{"id":63,"date":"2026-07-12T01:22:01","date_gmt":"2026-07-12T01:22:01","guid":{"rendered":"https:\/\/fibersandfaith.com\/?p=63"},"modified":"2026-07-12T01:26:55","modified_gmt":"2026-07-12T01:26:55","slug":"understanding-mutations-part-one-my-case","status":"publish","type":"post","link":"https:\/\/fibersandfaith.com\/?p=63","title":{"rendered":"Understanding Mutations &#8211; Part ONE &#8211; My case"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">This is going to be a comprehensive, detailed document covering everything about MY specific mutations <mark style=\"background-color:#fcb900\" class=\"has-inline-color has-black-color\">and a thorough general genetics education section\u00a0 THIS WILL BE IN PART TWO<\/mark>. &#8211; Please note anything highlighted <mark style=\"background-color:#fcb900\" class=\"has-inline-color has-black-color\">yellow <\/mark>either means its a start of a new topic , its important or it specifically indicates my specific case.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>PART ONE: MY SPECIFIC MUTATIONS \u2014 COMPLETE ANALYSIS<\/strong><\/h2>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>THE RYR1 GENE \u2014 FOUNDATIONAL UNDERSTANDING<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Before analyzing <mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MY<\/mark> specific mutations, understanding the gene itself is essential, i know i posted about the basic information on the gene in the last blog but i want to go over the understanding here as well before i get into my Gene mutations so its more clear.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Gene Location and Size<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Chromosome:<\/strong> 19 (specifically 19q13.2 \u2014 the long arm of chromosome 19, region 13, band 2)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Total size:<\/strong> Approximately 150,000 base pairs of DNA<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Number of exons:<\/strong> 106 (coding segments)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Total protein length:<\/strong> 5,037 amino acids<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Classification:<\/strong> One of the largest known human genes<br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">The RYR1 Protein Structure \u2014 Critical for Understanding Mutation Effects\u00a0<\/mark><\/strong>\n<ul class=\"wp-block-list\">\n<li>The RYR1 protein functions as a homotetramer \u2014 meaning four identical RYR1 protein subunits must assemble together to form one functional calcium channel complex. This assembly is critical because:\u00a0\n<ul class=\"wp-block-list\">\n<li>Each subunit is enormous (5,037 amino acids, ~560 kilodaltons)<\/li>\n\n\n\n<li>Four subunits together create a channel weighing approximately 2.2 megadaltons \u2014 one of the largest known protein complexes in biology\n<ul class=\"wp-block-list\">\n<li>If even ONE subunit is severely dysfunctional, it can disrupt the entire tetramer<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">The protein has distinct structural and functional zones:\u00a0<\/mark><\/strong>\n<ul class=\"wp-block-list\">\n<li><strong>N-terminal cytoplasmic domain (approximately aa 1\u20133,600):<\/strong>\u00a0<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li>Forms the massive &#8220;foot&#8221; structure visible under electron microscopy<\/li>\n\n\n\n<li>Contains regulatory binding sites for dozens of other proteins (calmodulin, FKBP12, PKA, calsequestrin, triadin, junction)\n<ul class=\"wp-block-list\">\n<li>Contains the &#8220;hot spot&#8221; regions where most pathogenic mutations cluster<\/li>\n\n\n\n<li>Houses the allosteric regulation machinery \u2014 sites where signals from outside the cell (metabolic state, redox status, pH, temperature) modulate channel activity<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Central linker\/regulatory domain (approximately aa 3,600\u20134,200):\u00a0<\/mark><\/strong>\n<ul class=\"wp-block-list\">\n<li>Connects the cytoplasmic regulatory domain to the transmembrane pore<\/li>\n\n\n\n<li>Contains critical inter-domain contacts that transmit conformational changes from regulatory sites to the pore<\/li>\n\n\n\n<li><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MY <\/mark>maternal frameshift mutation falls at the BEGINNING of this region (aa 4,189) \u2014 disrupting the critical connection between the regulatory machinery and the channel pore<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Transmembrane\/pore domain (approximately aa 4,200\u20135,037):<\/mark><\/strong>\n<ul class=\"wp-block-list\">\n<li>Embeds in the sarcoplasmic reticulum membrane<\/li>\n\n\n\n<li>Forms the actual calcium-conducting pore<\/li>\n\n\n\n<li>Contains the selectivity filter \u2014 the molecular &#8220;gate&#8221; that allows Ca\u00b2\u207a through while blocking other ions<\/li>\n\n\n\n<li>Contains the luminal (SR interior) calcium sensing region<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">The Three Established RYR1 Mutation Hotspot Regions\u00a0<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Scientists have identified three regions of the RYR1 protein where pathogenic mutations cluster disproportionately: <br><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Hotspot 1: <\/strong>Approximately amino acids 35\u2013614 (N-terminal)<\/li>\n\n\n\n<li><strong>Hotspot 2: <\/strong>Approximately amino acids 2,163\u20132,458 (central)<\/li>\n\n\n\n<li><strong>Hotspot 3<\/strong>: Approximately amino acids 4,136\u20134,973 (C-terminal) \u2014 <mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MY MATERNAL MUTATION FALLS HERE<\/mark><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The fact that pathogenic mutations cluster in these regions \u2014 rather than being evenly distributed across the protein \u2014 tells scientists these regions are functionally critical and that mutations here disproportionately disrupt normal channel function.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><br><br><br><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MY MUTATION #1 (MATERNAL) \u2014 THE PATHOGENIC VARIANT <br>Full Designation<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">RYR1, Exon 90, c.12567del (p.Ile4189Metfs*21), heterozygous, PATHOGENIC<\/mark><\/strong><br>Breaking Down Every Part of This Name\u00a0<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">&#8220;RYR1&#8221;<\/mark><\/strong> \u2014 The gene affected.<br><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">&#8220;Exon 90&#8221;<\/mark><\/strong> \u2014 The location within the gene.\u00a0\n<ul class=\"wp-block-list\">\n<li>The RYR1 gene has 106 exons total<\/li>\n\n\n\n<li>Exon 90 is in the later portion of the gene \u2014 near but not at the very end<\/li>\n\n\n\n<li>At the protein level, exon 90 encodes amino acids in the critical C-terminal hotspot region (Hotspot 3)<\/li>\n\n\n\n<li>Exons in the C-terminal region of RYR1 encode the linker domain connecting regulatory machinery to the transmembrane pore \u2014 a structurally and functionally critical transition zone<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">&#8220;c.12567del&#8221; \u2014 The DNA-level change.\u00a0<\/mark><\/strong>\n<ul class=\"wp-block-list\">\n<li>&#8220;c.&#8221; = coding sequence (the DNA that actually codes for protein, as opposed to regulatory\/intronic regions)<\/li>\n\n\n\n<li>&#8220;12567&#8221; = the position number within the coding sequence where the change occurs (the 12,567th nucleotide of the coding sequence)<\/li>\n\n\n\n<li>&#8220;del&#8221; = deletion \u2014 one single nucleotide (one DNA &#8220;letter&#8221;) has been deleted at this position<\/li>\n\n\n\n<li>This is a single nucleotide deletion \u2014 the smallest possible type of deletion mutation<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">&#8220;p.Ile4189Metfs*21&#8221; \u2014 The protein-level consequence.\u00a0<\/mark><\/strong>\n<ul class=\"wp-block-list\">\n<li>&#8220;p.&#8221; = protein (this part of the name describes what happens to the protein)<\/li>\n\n\n\n<li>&#8220;Ile&#8221; = Isoleucine \u2014 the amino acid that <strong>SHOULD<\/strong> be at position 4,189 in the normal protein<\/li>\n\n\n\n<li>&#8220;4189&#8221; = amino acid position 4,189 out of 5,037 total \u2014 approximately 83% of the way through the protein<\/li>\n\n\n\n<li>&#8220;Met&#8221; = Methionine \u2014 the first amino acid that is <strong>INCORRECTLY<\/strong> incorporated after the frameshift begins (because the reading frame has shifted, the codon at position 4,189 now reads as methionine instead of isoleucine)<\/li>\n\n\n\n<li>&#8220;fs&#8221; = frameshift \u2014 the critical descriptor; the deletion has shifted the reading frame<\/li>\n\n\n\n<li>&#8220;*21&#8221; = a premature stop codon appears 21 amino acids AFTER the frameshift begins \u2014 the protein is cut off at position 4,189+21 = approximately amino acid 4,210 instead of the normal 5,037<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">The Frameshift Mechanism \u2014 Explained In Complete Detail\u00a0<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">To understand why a single deleted nucleotide causes such catastrophic consequences,<mark style=\"background-color:#fcb900\" class=\"has-inline-color\"> MY and OUR<\/mark>\u00a0 need to understand how DNA is translated into protein.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">The Genetic Code \u2014 Triplet Codons:<\/mark><\/strong><br><br>DNA is read in groups of three nucleotides called <strong>codons<\/strong>. Each codon specifies exactly one amino acid. The sequence of codons in a gene determines the sequence of amino acids in the protein.\u00a0<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Normal DNA:&nbsp; &#8230;AAT CGT TAC GGA TTC&#8230;<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Codons: &nbsp; &nbsp; &nbsp; &nbsp; AAT | CGT | TAC | GGA | TTC<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Amino acids:&nbsp; &nbsp; Asn | Arg | Tyr | Gly | Phe<\/strong><strong><br><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">What a single nucleotide deletion does:\u00a0<\/mark><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When ONE nucleotide is deleted, every codon from that point forward is shifted by one position. This is the<strong> frameshift effect:<\/strong>\u00a0<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Normal:&nbsp; &nbsp; &#8230;AAT CGT TAC GGA TTC&#8230;<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#8230;Asn-Arg-Tyr-Gly-Phe&#8230;<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>After deleting one nucleotide (in this illustration, the &#8220;A&#8221; at position 1 of the second codon):<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Mutated: &nbsp; &#8230;AAT GTT ACG GAT TC&#8230;<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#8230;Asn-Val-Thr-Asp-STOP?&#8230;<\/strong><strong><br><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Every single codon from the deletion point forward reads completely differently \u2014 it&#8217;s like removing one space from a sentence and having every word after it scramble:<\/mark><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Normal: &#8220;THE CAT SAT ON THE MAT&#8221;<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Delete one letter: &#8220;THE ATS ATO NT HEM AT&#8221; \u2014 complete nonsense from the deletion point forward <\/strong><strong><br><\/strong><strong><br><\/strong><strong>The specific effect of c.12567del in RYR1:\u00a0<\/strong><\/li>\n<\/ul>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The single nucleotide deletion occurs at coding position 12,567<\/li>\n\n\n\n<li>From that point forward, every codon reads differently<\/li>\n\n\n\n<li>This means the amino acid sequence of the protein is COMPLETELY WRONG from position 4,189 onward<\/li>\n\n\n\n<li>After scrambling through 21 incorrect amino acids, the new reading frame generates a premature stop codon (UAA, UAG, or UGA in RNA)<\/li>\n\n\n\n<li>The ribosome (the cellular machine that builds proteins) stops when it hits this stop codon<\/li>\n\n\n\n<li>The resulting truncated protein would be approximately 4,210 amino acids long instead of the normal 5,037 \u2014 missing the entire C-terminal transmembrane and pore domain<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">BUT \u2014 the protein is almost certainly never even made:\u00a0<\/mark><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The cell has a quality control system called <strong>Nonsense-Mediated Decay (NMD).<\/strong> NMD recognizes messenger RNA molecules that contain premature stop codons (specifically those that occur more than ~50-55 nucleotides before the last exon-exon junction) and <strong>degrades them before they can be translated into protein.<\/strong><br><br><br><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MY<\/mark> mutation&#8217;s premature stop codon in Exon 90 (of 106 total exons) almost certainly triggers NMD \u2014 meaning the cell destroys the mutant mRNA transcript before a truncated protein can even be produced. The end result is that this allele contributes essentially <strong>ZERO RYR1 protein to the cellular pool.<\/strong><br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>This is the most severe possible mutation class: a null allele \u2014 producing nothing.<br><br><br><strong>Why This Specific Location Matters <\/strong><strong><br><\/strong>Position 4,189 sits at the beginning of the critical junction between:<br><br>The cytoplasmic regulatory domain (where the &#8220;decision&#8221; to open is made)<\/li>\n\n\n\n<li>The transmembrane pore domain (where calcium actually flows through)<br><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Even if NMD did NOT occur and a truncated protein WERE made, it would:\u00a0<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Lack the entire transmembrane anchoring domain (cannot even insert into the SR membrane properly)<\/li>\n\n\n\n<li>Lack the pore-forming region (cannot conduct calcium)<\/li>\n\n\n\n<li>Lack the C-terminal regulatory regions that control channel gating<\/li>\n\n\n\n<li>Potentially act as a dominant negative if it could still dimerize with normal subunits \u2014 poisoning the tetramer assembly<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>In every scenario, this mutation produces no functional contribution to RYR1 channel activity from the maternal allele.\u00a0<\/strong><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Population Frequency \u2014 The Significance of Zero <br><br>The fact that c.12567del is absent from all population databases \u2014 specifically from:\u00a0<\/mark><\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>ExAC (Exome Aggregation Consortium) \u2014 60,706 individuals<\/li>\n\n\n\n<li>gnomAD (Genome Aggregation Database) \u2014 141,456 exomes + 15,708 genomes (v2.1.1) and expanding versions<\/li>\n\n\n\n<li>dbSNP \u2014 does not have a registered rsID for this variant<\/li>\n\n\n\n<li>1000 Genomes Project<\/li>\n\n\n\n<li>ESP (Exome Sequencing Project)<\/li>\n\n\n\n<li>Invitae&#8217;s own internal database of all tested individuals<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">and has never been published in the peer-reviewed literature in association with any other patient \u2014 tells us several important things:\u00a0<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>This mutation is so rare it has never been independently rediscovered in any sequenced human population worldwide<\/strong><\/li>\n\n\n\n<li><strong>Natural selection acts against it (individuals with this mutation have reduced reproductive fitness due to disease)<\/strong><\/li>\n\n\n\n<li><strong>It is almost certainly a de novo or very recently arisen mutation within the family lineage \u2014 not an ancient inherited variant that spread through a population<\/strong><\/li>\n\n\n\n<li><strong>It cannot be classified using the typical evidence framework (population frequency comparisons) because there is nothing to compare it to \u2014 its pathogenicity is determined by its MECHANISM (frameshift \u2192 premature <\/strong><strong><br><\/strong><strong>stop \u2192 NMD \u2192 null allele) rather than by frequency data<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>The clinical implication of zero population frequency:<\/strong> This variant exists in essentially no other human being on Earth currently known to science. <mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MY<\/mark> maternal RYR1 allele is, to the best of current scientific knowledge, unique to <mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MY <\/mark>and <mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MY<\/mark>\u00a0 family line<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">Proof: this is my genetic report and what it states<\/mark>\u00a0<\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"742\" height=\"178\" src=\"https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/image_2026-07-11_205133314.png\" alt=\"\" class=\"wp-image-66\" style=\"aspect-ratio:4.168734491315137;width:840px;height:auto\" srcset=\"https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/image_2026-07-11_205133314.png 742w, https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/image_2026-07-11_205133314-300x72.png 300w, https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/image_2026-07-11_205133314-600x144.png 600w\" sizes=\"auto, (max-width: 742px) 100vw, 742px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">ACMG Classification Criteria \u2014 Why &#8220;PATHOGENIC&#8221; Despite Novelty<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The American College of Medical Genetics and Genomics (ACMG) has established a five-tier classification system for genetic variants:\u00a0<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Pathogenic<\/strong><\/li>\n\n\n\n<li><strong>Likely Pathogenic<\/strong><\/li>\n\n\n\n<li><strong>Variant of Uncertain Significance (VUS)<\/strong><\/li>\n\n\n\n<li><strong>Likely Benign<\/strong><\/li>\n\n\n\n<li><strong>Benign<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MY<\/mark> maternal variant received the highest-confidence classification: PATHOGENIC. Despite never having been seen before, it received this classification because the ACMG criteria include strong evidence categories that apply to<mark style=\"background-color:#fcb900\" class=\"has-inline-color\"> MY<\/mark> variant even without prior reports:\u00a0<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">PVS1 (Very Strong evidence \u2014 Pathogenic):<\/mark><\/strong><br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Null variant (frameshift, nonsense, splice site, large deletion) in a gene where loss-of-function is a known disease mechanism. &#x2705;<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">RYR1 is a well-established disease gene<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Loss-of-function variants in RYR1 are known pathogenic (PMIDs cited in the lab report: 20583297, 20839240, 23919265, 28818389)<\/strong><\/li>\n\n\n\n<li><strong>Your frameshift with premature stop \u2192 NMD \u2192 null allele is the prototypical PVS1 scenario<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\"><strong>PM2 (Moderate evidence \u2014 Pathogenic)<\/strong>:<\/mark><br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Absent from population databases in a recessive disease context. &#x2705;<br><br><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Zero frequency in ExAC\/gnomAD<\/mark><\/strong><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">PP4 (Supporting evidence \u2014 Pathogenic):\u00a0<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Patient phenotype consistent with the gene-disease relationship. &#x2705;<br><br><strong>MY clinical presentation is consistent with RYR1-related myopathy <br><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>The combination of PVS1 alone is often sufficient for Pathogenic classification <\/strong>\u2014 the other criteria further support it. This is why a never-before-seen variant can be definitively called Pathogenic: the mechanism (not the frequency) determines pathogenicity for null alleles.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><br><br><br><br><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MY MUTATIONS #2, #3, AND #4 (PATERNAL) \u2014 THE VUS TRIO<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">These three variants are all on the SAME chromosome (in cis) \u2014 meaning they were inherited together as a single haplotype from<mark style=\"background-color:#fcb900\" class=\"has-inline-color\"> MY<\/mark> father. This is critically important for interpretation<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Mutation #2 (Paternal) <br>Full Designation:<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>RYR1, Exon 67, c.10097G>A (p.Arg3366His), heterozygous, Variant of Uncertain Significance<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Breaking Down the Name<\/mark><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">&#8220;Exon 67&#8221; <\/mark>\u2014 <\/strong>Approximately two-thirds of the way through the gene\u00a0<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Located in the large cytoplasmic regulatory domain of the protein<\/li>\n\n\n\n<li>Not within the canonical hotspot regions (though close to the boundaries of Hotspot 2)<\/li>\n\n\n\n<li>This region contains important inter-domain communication pathways<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\"><strong>&#8220;c.10097G>A&#8221;<\/strong> \u2014 DNA-level change\u00a0<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Position 10,097 in the coding sequence<\/li>\n\n\n\n<li>&#8220;G>A&#8221; = a Guanine nucleotide has been replaced by an Adenine nucleotide<\/li>\n\n\n\n<li>This is a <strong>single nucleotide variant (SNV)<\/strong> \u2014 a substitution, NOT a deletion (completely different from your maternal mutation)<\/li>\n\n\n\n<li>One letter changed to another letter \u2014 the reading frame is NOT disrupted<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\"><strong>&#8220;p.Arg3366His&#8221;<\/strong> \u2014 Protein-level consequence\u00a0<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>&#8220;Arg&#8221; = Arginine \u2014 the normal amino acid at position 3,366<\/li>\n\n\n\n<li>&#8220;3366&#8221; = amino acid position 3,366 out of 5,037<\/li>\n\n\n\n<li>&#8220;His&#8221; = Histidine \u2014 the amino acid that is INCORRECTLY present due to this mutation<\/li>\n\n\n\n<li>This is a <strong>missense mutation<\/strong> \u2014 a single amino acid substitution<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">The Arginine-to-Histidine Change \u2014 Why It Matters\u00a0<\/mark><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Arginine (Arg, R):<\/strong><br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Positively charged at physiological pH<\/li>\n\n\n\n<li>One of the most basic (high pH) amino acids<\/li>\n\n\n\n<li>Frequently involved in electrostatic interactions with negatively charged residues, DNA, and phospholipids<\/li>\n\n\n\n<li>Often found at sites critical for protein-protein interactions and allosteric regulation<\/li>\n\n\n\n<li>The guanidinium group of arginine can form multiple hydrogen bonds simultaneously \u2014 making it a very &#8220;sticky&#8221; amino acid at interaction interfaces<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Histidine (His, H):<\/mark><\/strong><br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Partially positively charged at physiological pH (pKa ~6.0, so it&#8217;s transitioning between charged and uncharged near neutral pH)<\/li>\n\n\n\n<li>Much weaker positive charge than arginine<\/li>\n\n\n\n<li>Histidine is unique in being able to switch between protonated (charged) and neutral states near physiological pH \u2014 making it a frequent participant in enzyme active sites<\/li>\n\n\n\n<li>Cannot form as many or as strong hydrogen bonds as arginine<\/li>\n\n\n\n<li>Physically smaller than arginine<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">The physicochemical impact:<\/mark><\/strong><br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Replacing a strong, consistently positively charged arginine with a weaker, partially-charged histidine at position 3,366 is a moderate physicochemical change \u2014 not as drastic as replacing a charged amino acid with a neutral or hydrophobic one, but not trivially benign either<\/li>\n\n\n\n<li>The Invitae report specifically notes &#8220;there is a small physicochemical difference between arginine and histidine&#8221; \u2014 a slight understatement of the actual charge and size differences<\/li>\n\n\n\n<li>At a site in the inter-domain communication region of RYR1, this change could alter local electrostatic interactions, protein-protein binding surfaces, or allosteric signal transmission<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Population Frequency<\/mark><\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>rsID: rs137932199<\/strong><\/li>\n\n\n\n<li><strong>ExAC frequency: approximately 0.1% (1 in 1,000 people in the database)<\/strong><\/li>\n\n\n\n<li><strong>Context: 0.1% is rare but NOT ultra-rare \u2014 this variant exists in the general population at low frequency<\/strong><\/li>\n\n\n\n<li><strong>Important interpretation: The presence of this variant at 0.1% frequency means it CAN exist in healthy individuals \u2014 arguing AGAINST it being fully penetrant dominant pathogenic on its own. However, in the context of recessive disease (combined with other variants on the same allele and the pathogenic null allele on the other chromosome), its individually modest frequency is less reassuring.<\/strong><strong><br><\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Computational Predictions (Contradictory \u2014 Hence VUS)<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>SIFT: &#8220;Deleterious&#8221; \u2014 predicts this substitution disrupts protein function<\/li>\n\n\n\n<li>PolyPhen-2: &#8220;Benign&#8221; \u2014 predicts this substitution is tolerated<\/li>\n\n\n\n<li>Align-GVGD: &#8220;Class CO&#8221; \u2014 predicts no significant impact<\/li>\n\n\n\n<li>Interpretation: When computational tools disagree, no single prediction should be trusted \u2014 this disagreement itself supports VUS classification<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">ClinVar Entry<\/mark><\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>ClinVar Variation ID: 132990<\/strong><\/li>\n\n\n\n<li><strong>Multiple submissions from different laboratories and families, with various interpretations \u2014 the fact that ClinVar contains an entry means this variant has been encountered before in clinical genetic testing, and the accumulating evidence is what keeps it in the VUS (rather than Benign) category<\/strong><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">PROOF HERE: and what the genetic report states<\/mark><\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"751\" height=\"323\" src=\"https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/proof-2.png\" alt=\"\" class=\"wp-image-67\" style=\"width:840px;height:auto\" srcset=\"https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/proof-2.png 751w, https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/proof-2-300x129.png 300w, https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/proof-2-600x258.png 600w\" sizes=\"auto, (max-width: 751px) 100vw, 751px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><br><br><br><br><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Mutation #3 (Paternal)<\/mark><\/strong><br><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Full Designation:<\/strong><strong><br><\/strong><strong> RYR1, Exon 86, c.11798A&gt;G (p.Tyr3933Cys), heterozygous, Variant of Uncertain Significance<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Breaking Down the Name<\/mark><\/strong><br><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">&#8220;Exon 86&#8221; \u2014 Very late in the gene (86 of 106 exons)<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Located within or near Hotspot 3 (C-terminal, aa 4,136\u20134,973 approximately \u2014 though the exact hotspot boundaries vary by source, this exon encodes residues approaching that region)<\/li>\n\n\n\n<li>Getting close to the transmembrane\/pore region of the protein<\/li>\n\n\n\n<li>This region is highly conserved across species \u2014 a sign that changes here are more likely to be damaging<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">&#8220;c.11798A>G&#8221; \u2014 DNA-level change<\/mark><\/strong><br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Position 11,798 in the coding sequence<\/li>\n\n\n\n<li>&#8220;A>G&#8221; = Adenine replaced by Guanine<\/li>\n\n\n\n<li>Single nucleotide substitution \u2014 reading frame preserved<\/li>\n\n\n\n<li>A missense substitution at the DNA level<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">&#8220;p.Tyr3933Cys&#8221; \u2014 Protein-level consequence<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>&#8220;Tyr&#8221; = Tyrosine \u2014 the normal amino acid at position 3,933<\/li>\n\n\n\n<li>&#8220;3933&#8221; = amino acid position 3,933 out of 5,037 \u2014 approximately 78% through the protein<\/li>\n\n\n\n<li>&#8220;Cys&#8221; = Cysteine \u2014 the amino acid introduced by this mutation<\/li>\n\n\n\n<li>This is a missense mutation \u2014 single amino acid substitution<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><br><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">The Tyrosine-to-Cysteine Change \u2014 Why This Is More Concerning Than #2<\/mark><\/strong><br><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Tyrosine (Tyr, Y):<\/mark><\/strong><br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Large aromatic (ring-containing) amino acid<\/li>\n\n\n\n<li>Has a hydroxyl (-OH) group on its aromatic ring<\/li>\n\n\n\n<li>Can form hydrogen bonds through the hydroxyl group<\/li>\n\n\n\n<li>Participates in protein-protein interactions through both hydrophobic stacking (aromatic ring) and hydrogen bonding (hydroxyl)<\/li>\n\n\n\n<li>Often found at functionally important sites \u2014 enzyme active sites, protein interaction surfaces, signaling phosphorylation sites (tyrosine is a major phosphorylation target)<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Cysteine (Cys, C):<\/mark><\/strong><br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Small amino acid with a sulfhydryl (-SH) group<\/li>\n\n\n\n<li>Completely different chemical character from tyrosine \u2014 different size, different charge, different reactivity<\/li>\n\n\n\n<li>The sulfhydryl group of cysteine can form disulfide bonds with other cysteines \u2014 structurally critical but abnormal disulfide bonds could severely disrupt protein folding<\/li>\n\n\n\n<li>Cysteines introduced at non-native positions can cause abnormal protein aggregation or misfolding<\/li>\n\n\n\n<li>The Invitae report specifically notes &#8220;there is a large physicochemical difference between tyrosine and cysteine&#8221; \u2014 this is accurate and significant<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Why this substitution is more concerning than p.Arg3366His:<\/mark><\/strong><br><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Larger physicochemical difference \u2014 Tyr\u2192Cys is a more dramatic chemical change than Arg\u2192His<\/li>\n\n\n\n<li>Cysteine&#8217;s unique reactivity \u2014 an ectopic (incorrectly placed) cysteine can form aberrant disulfide bonds that misfolded the protein<\/li>\n\n\n\n<li>Location in a highly conserved region \u2014 amino acid 3,933 is in a region closer to the critical transmembrane domain, where the protein sequence is under stronger evolutionary pressure to remain unchanged<\/li>\n\n\n\n<li>The tyrosine residue at 3,933 may be functionally important \u2014 if it&#8217;s in an interdomain contact region or a post-translational modification site, replacing it disrupts that specific function<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Population Frequency<\/mark><\/strong><br><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>rsID: rs147136339<\/strong><\/li>\n\n\n\n<li><strong>ExAC frequency: approximately 0.1%<\/strong><\/li>\n\n\n\n<li><strong>Same frequency level as p.Arg3366His \u2014 both exist in the general population at low but non-zero frequency<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Computational Predictions (Also Contradictory)<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>SIFT: &#8220;Deleterious&#8221;<\/strong><\/li>\n\n\n\n<li><strong>PolyPhen-2: &#8220;Benign&#8221;<\/strong><\/li>\n\n\n\n<li><strong>Align-GVGD: &#8220;Class CO&#8221;<\/strong><\/li>\n\n\n\n<li><strong>Same pattern of disagreement as mutation #2<\/strong><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">ClinVar Entry<\/mark><\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>ClinVar Variation ID: 133021<\/strong><\/li>\n\n\n\n<li><strong>Multiple entries in ClinVar \u2014 has been reported in affected individuals<\/strong><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">PROOF HERE: What the genetic test states<\/mark><\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"742\" height=\"403\" src=\"https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/proof-3.png\" alt=\"\" class=\"wp-image-69\" style=\"width:786px;height:auto\" srcset=\"https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/proof-3.png 742w, https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/proof-3-300x163.png 300w, https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/proof-3-600x326.png 600w\" sizes=\"auto, (max-width: 742px) 100vw, 742px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\"><br><br><br><br><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Mutation #4 (Paternal)<\/mark><\/strong><br><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Full Designation:<br> RYR1, Exon 33, c.4711A>G (p.Ile1571Val), heterozygous, Variant of Uncertain Significance<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Breaking Down the Name<\/mark><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">&#8220;Exon 33&#8221; \u2014 In the first half of the gene<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Located within Hotspot 1 (approximately aa 35\u2013614) OR between Hotspot 1 and Hotspot 2<\/li>\n\n\n\n<li>Actually at amino acid position 1,571 \u2014 this is PAST the canonical Hotspot 1 boundary but BEFORE Hotspot 2<\/li>\n\n\n\n<li>However, Hotspot boundaries are somewhat loosely defined and different papers use slightly different ranges<\/li>\n\n\n\n<li>This region is part of the large N-terminal cytoplasmic regulatory domain<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">&#8220;c.4711A>G&#8221; \u2014 DNA-level change<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Position 4,711 in the coding sequence<\/li>\n\n\n\n<li>&#8220;A>G&#8221; = Adenine replaced by Guanine<\/li>\n\n\n\n<li>Single nucleotide substitution<\/li>\n\n\n\n<li>Missense substitution \u2014 reading frame preserved<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">&#8220;p.Ile1571Val&#8221; \u2014 Protein-level consequence<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>&#8220;Ile&#8221; = Isoleucine \u2014 the normal amino acid at position 1,571<\/li>\n\n\n\n<li>&#8220;1571&#8221; = amino acid position 1,571 out of 5,037 \u2014 approximately 31% through the protein<\/li>\n\n\n\n<li>&#8220;Val&#8221; = Valine \u2014 the amino acid introduced by this mutation<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">The Isoleucine-to-Valine Change \u2014 The Most Conservative of the Three<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Isoleucine (Ile, I):<\/mark><\/strong><br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Nonpolar, hydrophobic (water-repelling) amino acid<\/li>\n\n\n\n<li>Has a branched side chain<\/li>\n\n\n\n<li>Medium-large size<\/li>\n\n\n\n<li>Typically buried in the hydrophobic core of proteins<\/li>\n\n\n\n<li>No charge, no reactive groups<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Valine (Val, V):<\/mark><\/strong><br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>ALSO nonpolar, hydrophobic amino acid<\/li>\n\n\n\n<li>Has a branched side chain (slightly smaller than isoleucine)<\/li>\n\n\n\n<li>Similar chemical character to isoleucine but slightly smaller<\/li>\n\n\n\n<li>Also typically buried in hydrophobic protein cores<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Why this is the &#8220;mildest&#8221; of the three paternal variants:<\/mark><\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Very small physicochemical difference \u2014 Ile and Val are both nonpolar, hydrophobic amino acids; they are chemically very similar<\/strong><\/li>\n\n\n\n<li><strong>No change in charge, polarity, or reactivity \u2014 unlike the Arg\u2192His or Tyr\u2192Cys changes<\/strong><\/li>\n\n\n\n<li><strong>The Invitae report notes &#8220;small physicochemical difference&#8221; for this variant \u2014 consistent with the chemistry<\/strong><\/li>\n\n\n\n<li><strong>Highest population frequency (0.5%) among the three paternal VUS variants \u2014 1 in 200 people in ExAC carry this variant<\/strong><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Why it is NOT considered benign despite seeming mild:<\/mark><\/strong><br><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Isoleucine 1,571 is highly conserved \u2014 the Invitae report specifically notes &#8220;the isoleucine residue is highly conserved&#8221; \u2014 meaning natural evolution has strongly preserved this amino acid at this position across many species, suggesting changes here disrupt important function<\/strong><\/li>\n\n\n\n<li><strong>It travels with two other more impactful variants on the same allele \u2014 the cumulative effect of all three variants together on the same chromosome may be synergistic<\/strong><\/li>\n\n\n\n<li><strong>It has been reported as part of the trio in affected individuals \u2014 though the three-variant cluster&#8217;s individual contribution cannot be fully disentangled<\/strong><\/li>\n\n\n\n<li><strong>Location in a regulatory domain \u2014 even conservative amino acid changes in critical regulatory positions can alter allosteric signaling<\/strong><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Population Frequency<\/mark><\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>rsID: rs146429605<\/strong><\/li>\n\n\n\n<li><strong>ExAC frequency: approximately 0.5% \u2014 the most common of your four RYR1 variants (excluding the novel null allele which has zero frequency)<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Computational Predictions<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>SIFT: &#8220;Deleterious&#8221;<\/strong><\/li>\n\n\n\n<li><strong>PolyPhen-2: &#8220;Benign&#8221;<\/strong><\/li>\n\n\n\n<li><strong>Align-GVGD: &#8220;Class CO&#8221;<\/strong><\/li>\n\n\n\n<li><strong>Same contradictory pattern as mutations #2 and #3<\/strong><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">ClinVar Entry<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>ClinVar Variation ID: 159851<\/strong><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">PROOF HERE: what the genetic report states<\/mark><\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"783\" height=\"344\" src=\"https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/ptoof-4.png\" alt=\"\" class=\"wp-image-71\" style=\"width:840px;height:auto\" srcset=\"https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/ptoof-4.png 783w, https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/ptoof-4-300x132.png 300w, https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/ptoof-4-768x337.png 768w, https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/ptoof-4-600x264.png 600w\" sizes=\"auto, (max-width: 783px) 100vw, 783px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">THE THREE-VARIANT HAPLOTYPE \u2014 THE CRITICAL CONCEPT<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The most important thing about mutations #2, #3, and #4 is that they are <strong>all on the same chromosome \u2014 <\/strong>they form a haplotype (a set of variants that are inherited together as a single unit).<\/p>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>Why This Matters More Than Any Individual Variant<\/strong><\/h4>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Consider the analogy of a recipe for a complex dish. One unusual ingredient substitution might be harmless. But three simultaneous unusual substitutions in the same recipe \u2014 one changing the salt, one changing the fat, and one changing the thickener \u2014 could interact to produce something entirely different from the intended dish, even if each substitution alone seemed minor.<\/strong><strong><br><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Similarly, when three missense variants exist on the same RYR1 allele:\u00a0<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Each variant individually makes a small structural change to the protein<\/li>\n\n\n\n<li>But these three changes are present SIMULTANEOUSLY in the same protein molecule<\/li>\n\n\n\n<li>Their effects may be additive (each adding a small disruption)<\/li>\n\n\n\n<li>Or synergistic (each change making the other changes worse)<\/li>\n\n\n\n<li>Or they may affect different functional aspects of the protein that together disrupt it more completely than any one would alone<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Variant 4 (p.Ile1571Val) \u2014 in the N-terminal regulatory domain, potentially affecting allosteric regulation signals<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Variant 2 (p.Arg3366His) \u2014 in the inter-domain communication region, potentially affecting signal transmission<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Variant 3 (p.Tyr3933Cys) \u2014 approaching the transmembrane domain, potentially affecting channel gating and calcium selectivity <\/strong><strong><br><\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Together on one allele, these three variants may produce a protein that:<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Receives regulatory signals abnormally (due to variant 4)<\/li>\n\n\n\n<li>Transmits those signals poorly (due to variant 2)<\/li>\n\n\n\n<li>Gates abnormally and may have altered calcium conductance or an aberrant disulfide bond (due to variant 3)<br><br><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">The Family Evidence That Makes This Trio Significant<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>The Invitae report cites multiple published PMIDs where exactly these three variants \u2014 p.Ile1571Val, p.Arg3366His, and p.Tyr3933Cys \u2014 have been reported TOGETHER in individuals and families with:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Malignant hyperthermia syndrome (MHS)<\/strong><\/li>\n\n\n\n<li><strong>Congenital myopathy<\/strong><\/li>\n\n\n\n<li><strong>Central core disease (CCD)<\/strong><\/li>\n\n\n\n<li><strong>Multiminicore disease (MmD<\/strong><strong>)<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">In some of those families, the phase (whether the three variants were on the same or different chromosomes) was established, and the trio was confirmed as a disease-associated haplotype. In others, phase could not be determined. <strong><br><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>The fact that this specific combination of three variants has been seen in multiple unrelated affected families is strong evidence that the trio together is clinically significant \u2014 even though no individual variant alone meets the threshold for Pathogenic or Likely Pathogenic classification. <br><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MY situation adds to this evidence<\/mark>:<mark style=\"background-color:#fcb900\" class=\"has-inline-color\"> I have all three variants on MY\u00a0 paternal allele<\/mark> (confirmed in cis by family history), AND<mark style=\"background-color:#fcb900\" class=\"has-inline-color\"> I have a null maternal allele, AND I \u00a0have a clinical presentation consistent with recessive RYR1 myopathy<\/mark>. This is exactly the pattern that builds the case for reclassifying the trio from VUS to Likely Pathogenic<strong>.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><br><br><br><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MY FIFTH MUTATION \u2014 THE PLEC VUS<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Full Designation:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>PLEC, Exon 32, c.6271_6282del (p.Glu2091_Gln2094del), heterozygous, Variant of Uncertain Significance\u00a0<\/strong><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">What Is PLEC<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>PLEC<\/strong> encodes the protein Plectin \u2014 a very large cytoskeletal linker protein (one of the largest in the human body, even larger than RYR1 at approximately 4,684 amino acids in its major isoform). <strong><br><br><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Plectin functions as a molecular scaffold and mechanical linker \u2014 it connects different cytoskeletal networks together:\u00a0<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Connects intermediate filaments to the sarcolemma (muscle cell outer membrane)<\/li>\n\n\n\n<li>Connects intermediate filaments to the nuclear membrane<\/li>\n\n\n\n<li>Connects intermediate filaments to desmosomes and hemidesmosomes (cell junction structures)<\/li>\n\n\n\n<li>Helps distribute mechanical forces across the cell to prevent damage during muscle contraction<\/li>\n\n\n\n<li>Critical for muscle cell structural integrity during the repeated stress of contraction<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Plectin is expressed in:<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Skeletal muscle (highly expressed)<\/li>\n\n\n\n<li>Skin (particularly the dermal-epidermal junction)<\/li>\n\n\n\n<li>Heart<\/li>\n\n\n\n<li>Neurons<\/li>\n\n\n\n<li>Many other tissues<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">PLEC-Related Diseases<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Because PLEC is expressed in multiple tissues, PLEC mutations cause a diverse group of conditions depending on which tissues are most affected:<\/strong><br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Autosomal recessive conditions (both copies affected): <\/strong><strong><br><\/strong><strong><br><\/strong>Epidermolysis Bullosa Simplex with Muscular Dystrophy (EBS-MD) \u2014 skin blistering from birth (due to skin junction failure) plus progressive muscle disease; MedGen UID 347335<\/li>\n\n\n\n<li>Epidermolysis Bullosa Simplex with Pyloric Atresia (EBS-PA) \u2014 skin blistering plus narrowing of the stomach outlet; MedGen UID 436922<\/li>\n\n\n\n<li>Epidermolysis Bullosa Simplex with Myasthenic Syndrome (EBS-MS) \u2014 skin blistering plus neuromuscular junction dysfunction (muscle weakness); PMID 21263134<\/li>\n\n\n\n<li>Limb-Girdle Muscular Dystrophy Type 2Q (LGMD2Q) \u2014 muscle disease affecting primarily the shoulder and hip girdle muscles, WITHOUT skin involvement; MedGen UID 462339<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Autosomal dominant condition (one copy sufficient):<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Epidermolysis Bullosa Simplex, Ogna type (EBS-Ogna) <\/strong>\u2014 a milder skin fragility disorder; MedGen UID 98488<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Breaking Down MY PLEC Mutation<\/mark><\/strong><br><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>&#8220;Exon 32&#8221; \u2014 One of PLEC&#8217;s many exons (PLEC has alternative splicing producing multiple isoforms, so exon numbering can vary by transcript used)<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">&#8220;c.6271_6282del&#8221; \u2014 DNA-level change <br><\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>&#8220;c.6271_6282&#8221; = a range of coding sequence positions from 6,271 to 6,282<\/strong><\/li>\n\n\n\n<li><strong>&#8220;del&#8221; = deletion<\/strong><\/li>\n\n\n\n<li><strong>6,282 \u2212 6,271 + 1 = 12 nucleotides deleted<\/strong><\/li>\n\n\n\n<li><strong>This is a 12-nucleotide in-frame deletion \u2014 critically different from <mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MYmaternal<\/mark> RYR1 frameshift<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">&#8220;p.Glu2091_Gln2094del&#8221; \u2014 Protein-level consequence\u00a0<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>&#8220;Glu2091&#8221; = Glutamic acid at position 2,091 (first deleted amino acid)<\/strong><\/li>\n\n\n\n<li><strong>&#8220;Gln2094&#8221; = Glutamine at position 2,094 (last deleted amino acid)<\/strong><\/li>\n\n\n\n<li><strong>&#8220;del&#8221; = deletion of this stretch<\/strong><\/li>\n\n\n\n<li><strong>FOUR AMINO ACIDS<\/strong><strong> (Glu-2091 through Gln-2094) are deleted from the plectin protein<\/strong><\/li>\n\n\n\n<li><strong>The reading frame IS preserved (12 nucleotides = 4 complete codons; deleting complete codons maintains the reading frame)<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">The In-Frame Deletion Mechanism<\/mark><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Because 12 nucleotides = exactly 4 complete codons, this deletion removes exactly 4 amino acids from the plectin protein while leaving the rest of the sequence intact. This is fundamentally different from <mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MY maternal<\/mark> RYR1 frameshift:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>RYR1 frameshift:<\/strong> 1 nucleotide deleted \u2192 all subsequent codons scrambled \u2192 nonsense-mediated decay \u2192 no protein<\/li>\n\n\n\n<li><strong>PLEC in-frame deletion:<\/strong> 12 nucleotides deleted \u2192 4 amino acids missing \u2192 rest of protein sequence intact \u2192 protein IS made but is missing 4 amino acids<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">A protein missing 4 amino acids can potentially:\u00a0<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Fold nearly normally (if those 4 amino acids are in a non-critical region)<\/strong><\/li>\n\n\n\n<li><strong>Have subtly altered function (if those amino acids are in a moderately important region)<\/strong><\/li>\n\n\n\n<li><strong>Have significantly altered function (if those amino acids are in a critical domain)<\/strong><\/li>\n\n\n\n<li><strong>Fail to fold properly (if those amino acids are essential for structural stability)<\/strong><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Why This PLEC Variant Is Classified VUS<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Several specific reasons from the Invitae report:<\/strong><br><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">&#8220;The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the ExAC database&#8221;<\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This means the ExAC\/gnomAD data at this genomic position has technical artifacts that make the frequency numbers untrustworthy \u2014 can&#8217;t use population frequency as evidence<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">No literature reports:<\/mark><\/strong><br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>&#8220;This variant has not been reported in the literature in individuals with PLEC-related conditions&#8221;<\/li>\n\n\n\n<li>Unlike the RYR1 trio which has appeared in affected families, this PLEC variant has no published clinical associations<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">No experimental data:<\/mark><\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>&#8220;Experimental studies and prediction algorithms are not available or were not evaluated for this variant&#8221;<\/li>\n\n\n\n<li>No functional studies have been done on this specific variant<\/li>\n\n\n\n<li>The functional significance of the affected amino acids (Glu2091-Gln2094) is currently unknown<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#fcb900\" class=\"has-inline-color\">Clinical Significance for ME<\/mark><\/strong><\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>At this time, this PLEC variant is considered a finding of uncertain significance that:<\/strong><br><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Is being monitored but NOT treated or managed specifically<\/li>\n\n\n\n<li>Does NOT by itself explain your clinical presentation<\/li>\n\n\n\n<li>Would require both copies of PLEC to be mutated for the recessive muscle conditions (LGMD2Q, EBS-MD, etc.) \u2014 <mark style=\"background-color:#fcb900\" class=\"has-inline-color\">I have only ONE copy affected<\/mark><\/li>\n\n\n\n<li>May be a completely benign variant that happens to have been found alongside <mark style=\"background-color:#fcb900\" class=\"has-inline-color\">MY RYR1 variants<\/mark><\/li>\n\n\n\n<li>Would require future functional studies or additional cases to be reclassified<\/li>\n\n\n\n<li>Is relevant to<mark style=\"background-color:#fcb900\" class=\"has-inline-color\"> MY mother\/father\/half-sibling <\/mark>if any of them were tested, as it might help understand whether this is a family variant<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><mark style=\"background-color:#7bdcb5\" class=\"has-inline-color\">PROOF: what the report states <\/mark><br><\/h2>\n\n\n\n<figure class=\"wp-block-image size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"713\" height=\"185\" src=\"https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/image_2026-07-11_211940437.png\" alt=\"\" class=\"wp-image-74\" style=\"width:734px;height:auto\" srcset=\"https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/image_2026-07-11_211940437.png 713w, https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/image_2026-07-11_211940437-300x78.png 300w, https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/image_2026-07-11_211940437-600x156.png 600w\" sizes=\"auto, (max-width: 713px) 100vw, 713px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#f78da7\" class=\"has-inline-color\">THE COMPOUND HETEROZYGOUS PICTURE \u2014 ALL VARIANTS TOGETHER<\/mark><\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>CHROMOSOME 19 \u2014 MATERNAL COPY:<\/strong><\/li>\n\n\n\n<li><strong>[Normal RYR1]&#8212;-[EXON 90: c.12567del]&#8212;-[Normal rest of gene]<\/strong><\/li>\n\n\n\n<li><strong>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u2193<\/strong><\/li>\n\n\n\n<li><strong>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0FRAMESHIFT \u2192 PREMATURE STOP \u2192 NMD \u2192 ZERO PROTEIN<\/strong><\/li>\n\n\n\n<li><strong>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0= Complete loss of function on this allele<\/strong><\/li>\n\n\n\n<li><\/li>\n\n\n\n<li><strong>CHROMOSOME 19 \u2014 PATERNAL COPY:<\/strong><\/li>\n\n\n\n<li><strong>[EXON 33: c.4711A>G]&#8212;-[EXON 67: c.10097G>A]&#8212;-[EXON 86: c.11798A>G]<\/strong><\/li>\n\n\n\n<li><strong>(p.Ile1571Val) \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 (p.Arg3366His) \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 (p.Tyr3933Cys)<\/strong><\/li>\n\n\n\n<li><strong>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u2193<\/strong><\/li>\n\n\n\n<li><strong>ALTERED RYR1 PROTEIN \u2014 all three changes present simultaneously<\/strong><\/li>\n\n\n\n<li><strong>= Protein is made but with potentially significant functional alterations<\/strong><\/li>\n\n\n\n<li><strong>= The only source of any RYR1 protein in <\/strong><strong>MY<\/strong><strong> muscle cells<\/strong><\/li>\n\n\n\n<li><\/li>\n\n\n\n<li><strong>CHROMOSOME (unknown) \u2014 ONE COPY:<\/strong><\/li>\n\n\n\n<li><strong>PLEC c.6271_6282del (p.Glu2091_Gln2094del)<\/strong><\/li>\n\n\n\n<li><strong>= In-frame deletion of 4 amino acids from plectin protein<\/strong><\/li>\n\n\n\n<li><strong>= Significance unknown; recessive disease requires BOTH copies affected<\/strong><\/li>\n\n\n\n<li><strong>\u00a0<\/strong><strong><br><\/strong><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong><mark style=\"background-color:#f78da7\" class=\"has-inline-color\">Net result: MY skeletal muscle cells have:<\/mark>\u00a0<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Zero functional RYR1 from the maternal allele<\/strong><\/li>\n\n\n\n<li><strong>Only the three-VUS-harboring protein from the paternal allele<\/strong><\/li>\n\n\n\n<li><strong>This single source of RYR1 protein must supply ALL the calcium release channel function for EVERY muscle cell in <\/strong><strong>MY<\/strong><strong> body<\/strong><\/li>\n\n\n\n<li><strong>If the paternal allele&#8217;s protein has reduced function (plausible given the three simultaneous missense changes), she has significantly sub-normal total RYR1 channel function<\/strong><\/li>\n\n\n\n<li><strong>Plus MH susceptibility from both the null allele and the paternal variants (the trio has appeared in MH-affected families)<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\"><br><br><br><strong>I WANTED TO SHARE MY RESULTS AND PROOF OF SO THAT IF ANYONE WHO HAS THE SAME EXACT MUTATIONS AS ME PLEASE REACT OUT AS IN THE DATABASE I APPEAR TO BE THE ONLY ONE WITH THE MATERNAL MUTATION WHICH CAN INDICATE MY SYMPTOMS COULD BE DIFFERENT THEN OTHERS AS THIS IS A NOT KNOWN VARIANT\u00a0<\/strong><br><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Please feel free to comment! Part TWO will come out soon<\/p>\n","protected":false},"excerpt":{"rendered":"<p>This is going to be a comprehensive, detailed document covering everything about MY specific mutations and a thorough general genetics education section\u00a0 THIS WILL BE IN PART TWO. &#8211; Please note anything highlighted yellow either means its a start of a new topic , its important or it specifically indicates my specific case. PART ONE: MY SPECIFIC MUTATIONS \u2014 COMPLETE ANALYSIS THE RYR1 GENE \u2014 FOUNDATIONAL UNDERSTANDING Before analyzing MY specific mutations, understanding the gene itself is essential, i know i posted about the basic information on the gene in the last blog but i want to go over the understanding here as well before i get into my Gene mutations so its more clear. Gene Location and Size Chromosome: 19 (specifically 19q13.2 \u2014 the long arm of chromosome 19, region 13, band 2) Total size: Approximately 150,000 base pairs of DNA Number of exons: 106 (coding segments) Total protein length: 5,037 amino acids Classification: One of the largest known human genes The Three Established RYR1 Mutation Hotspot Regions\u00a0 Scientists have identified three regions of the RYR1 protein where pathogenic mutations cluster disproportionately: The fact that pathogenic mutations cluster in these regions \u2014 rather than being evenly distributed across the protein \u2014 tells scientists these regions are functionally critical and that mutations here disproportionately disrupt normal channel function. MY MUTATION #1 (MATERNAL) \u2014 THE PATHOGENIC VARIANT Full Designation RYR1, Exon 90, c.12567del (p.Ile4189Metfs*21), heterozygous, PATHOGENICBreaking Down Every Part of This Name\u00a0 The Frameshift Mechanism \u2014 Explained In Complete Detail\u00a0 To understand why a single deleted nucleotide causes such catastrophic consequences, MY and OUR\u00a0 need to understand how DNA is translated into protein. The Genetic Code \u2014 Triplet Codons: DNA is read in groups of three nucleotides called codons. Each codon specifies exactly one amino acid. The sequence of codons in a gene determines the sequence of amino acids in the protein.\u00a0 Normal DNA:&nbsp; &#8230;AAT CGT TAC GGA TTC&#8230; Codons: &nbsp; &nbsp; &nbsp; &nbsp; AAT | CGT | TAC | GGA | TTC Amino acids:&nbsp; &nbsp; Asn | Arg | Tyr | Gly | Phe What a single nucleotide deletion does:\u00a0 When ONE nucleotide is deleted, every codon from that point forward is shifted by one position. This is the frameshift effect:\u00a0 Normal:&nbsp; &nbsp; &#8230;AAT CGT TAC GGA TTC&#8230; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#8230;Asn-Arg-Tyr-Gly-Phe&#8230; After deleting one nucleotide (in this illustration, the &#8220;A&#8221; at position 1 of the second codon): Mutated: &nbsp; &#8230;AAT GTT ACG GAT TC&#8230; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&#8230;Asn-Val-Thr-Asp-STOP?&#8230; Every single codon from the deletion point forward reads completely differently \u2014 it&#8217;s like removing one space from a sentence and having every word after it scramble: Normal: &#8220;THE CAT SAT ON THE MAT&#8221; BUT \u2014 the protein is almost certainly never even made:\u00a0 The cell has a quality control system called Nonsense-Mediated Decay (NMD). NMD recognizes messenger RNA molecules that contain premature stop codons (specifically those that occur more than ~50-55 nucleotides before the last exon-exon junction) and degrades them before they can be translated into protein. MY mutation&#8217;s premature stop codon in Exon 90 (of 106 total exons) almost certainly triggers NMD \u2014 meaning the cell destroys the mutant mRNA transcript before a truncated protein can even be produced. The end result is that this allele contributes essentially ZERO RYR1 protein to the cellular pool. Even if NMD did NOT occur and a truncated protein WERE made, it would:\u00a0 In every scenario, this mutation produces no functional contribution to RYR1 channel activity from the maternal allele.\u00a0 Population Frequency \u2014 The Significance of Zero The fact that c.12567del is absent from all population databases \u2014 specifically from:\u00a0 and has never been published in the peer-reviewed literature in association with any other patient \u2014 tells us several important things:\u00a0 The clinical implication of zero population frequency: This variant exists in essentially no other human being on Earth currently known to science. MY maternal RYR1 allele is, to the best of current scientific knowledge, unique to MY and MY\u00a0 family line Proof: this is my genetic report and what it states\u00a0 ACMG Classification Criteria \u2014 Why &#8220;PATHOGENIC&#8221; Despite Novelty The American College of Medical Genetics and Genomics (ACMG) has established a five-tier classification system for genetic variants:\u00a0 MY maternal variant received the highest-confidence classification: PATHOGENIC. Despite never having been seen before, it received this classification because the ACMG criteria include strong evidence categories that apply to MY variant even without prior reports:\u00a0 PVS1 (Very Strong evidence \u2014 Pathogenic): RYR1 is a well-established disease gene PM2 (Moderate evidence \u2014 Pathogenic): PP4 (Supporting evidence \u2014 Pathogenic):\u00a0 Patient phenotype consistent with the gene-disease relationship. &#x2705; MY clinical presentation is consistent with RYR1-related myopathy The combination of PVS1 alone is often sufficient for Pathogenic classification \u2014 the other criteria further support it. This is why a never-before-seen variant can be definitively called Pathogenic: the mechanism (not the frequency) determines pathogenicity for null alleles. MY MUTATIONS #2, #3, AND #4 (PATERNAL) \u2014 THE VUS TRIO These three variants are all on the SAME chromosome (in cis) \u2014 meaning they were inherited together as a single haplotype from MY father. This is critically important for interpretation Mutation #2 (Paternal) Full Designation: Breaking Down the Name &#8220;Exon 67&#8221; \u2014 Approximately two-thirds of the way through the gene\u00a0 &#8220;c.10097G>A&#8221; \u2014 DNA-level change\u00a0 &#8220;p.Arg3366His&#8221; \u2014 Protein-level consequence\u00a0 The Arginine-to-Histidine Change \u2014 Why It Matters\u00a0 Arginine (Arg, R): Histidine (His, H): The physicochemical impact: Population Frequency Computational Predictions (Contradictory \u2014 Hence VUS) ClinVar Entry PROOF HERE: and what the genetic report states Mutation #3 (Paternal) Full Designation: RYR1, Exon 86, c.11798A&gt;G (p.Tyr3933Cys), heterozygous, Variant of Uncertain Significance Breaking Down the Name &#8220;Exon 86&#8221; \u2014 Very late in the gene (86 of 106 exons) &#8220;c.11798A>G&#8221; \u2014 DNA-level change &#8220;p.Tyr3933Cys&#8221; \u2014 Protein-level consequence The Tyrosine-to-Cysteine Change \u2014 Why This Is More Concerning Than #2 Tyrosine (Tyr, Y): Cysteine (Cys, C): Why this substitution is more concerning than p.Arg3366His: Population Frequency Computational Predictions (Also Contradictory) ClinVar Entry PROOF HERE: What the genetic test states Mutation #4 (Paternal) Full Designation: RYR1, Exon 33, c.4711A>G (p.Ile1571Val), heterozygous, Variant of Uncertain Significance Breaking Down the Name &#8220;Exon 33&#8221; \u2014 In the first half of the gene &#8220;c.4711A>G&#8221; \u2014 DNA-level change &#8220;p.Ile1571Val&#8221; \u2014 Protein-level consequence The Isoleucine-to-Valine Change \u2014 The Most Conservative of the Three Isoleucine (Ile, I): Valine (Val, V): Why this is the &#8220;mildest&#8221; of the three paternal variants: Why it is NOT considered benign despite seeming mild: Population Frequency Computational Predictions ClinVar Entry ClinVar Variation ID: 159851 PROOF HERE: what the genetic report states THE THREE-VARIANT HAPLOTYPE \u2014 THE CRITICAL CONCEPT The most important thing about mutations #2, #3, and #4 is that they are all on the same chromosome \u2014 they form a haplotype (a set of variants that are inherited together as a single unit). Why This Matters More Than Any Individual Variant Consider the analogy of a recipe for a complex dish. One unusual ingredient substitution might be harmless. But three simultaneous unusual substitutions in the same recipe \u2014 one changing the salt, one changing the fat, and one changing the thickener \u2014 could interact to produce something entirely different from the intended dish, even if each substitution alone seemed minor. Similarly, when three missense variants exist on the same RYR1 allele:\u00a0 Variant 4 (p.Ile1571Val) \u2014 in the N-terminal regulatory domain, potentially affecting allosteric regulation signals Variant 2 (p.Arg3366His) \u2014 in the inter-domain communication region, potentially affecting signal transmission Together on one allele, these three variants may produce a protein that: The Family Evidence That Makes This Trio Significant The Invitae report cites multiple published PMIDs where exactly these three variants \u2014 p.Ile1571Val, p.Arg3366His, and p.Tyr3933Cys \u2014 have been reported TOGETHER in individuals and families with: In some of those families, the phase (whether the three variants were on the same or different chromosomes) was established, and the trio was confirmed as a disease-associated haplotype. In others, phase could not be determined. The fact that this specific combination of three variants has been seen in multiple unrelated affected families is strong evidence that the trio together is clinically significant \u2014 even though no individual variant alone meets the threshold for Pathogenic or Likely Pathogenic classification. MY situation adds to this evidence: I have all three variants on MY\u00a0 paternal allele (confirmed in cis by family history), AND I have a null maternal allele, AND I \u00a0have a clinical presentation consistent with recessive RYR1 myopathy. This is exactly the pattern that builds the case for reclassifying the trio from VUS to Likely Pathogenic. MY FIFTH MUTATION \u2014 THE PLEC VUS Full Designation: What Is PLEC PLEC encodes the protein Plectin \u2014 a very large cytoskeletal linker protein (one of the largest in the human body, even larger than RYR1 at approximately 4,684 amino acids in its major isoform). Plectin functions as a molecular scaffold and mechanical linker \u2014 it connects different cytoskeletal networks together:\u00a0 Plectin is expressed in: PLEC-Related Diseases Because PLEC is expressed in multiple tissues, PLEC mutations cause a diverse group of conditions depending on which tissues are most affected: Autosomal dominant condition (one copy sufficient): Breaking Down MY PLEC Mutation &#8220;Exon 32&#8221; \u2014 One of PLEC&#8217;s many exons (PLEC has alternative splicing producing multiple isoforms, so exon numbering can vary by transcript used) &#8220;c.6271_6282del&#8221; \u2014 DNA-level change &#8220;p.Glu2091_Gln2094del&#8221; \u2014 Protein-level consequence\u00a0 The In-Frame Deletion Mechanism Because 12 nucleotides = exactly 4 complete codons, this deletion removes exactly 4 amino acids from the plectin protein while leaving the rest of the sequence intact. This is fundamentally different from MY maternal RYR1 frameshift: A protein missing 4 amino acids can potentially:\u00a0 Why This PLEC Variant Is Classified VUS Several specific reasons from the Invitae report: &#8220;The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the ExAC database&#8221; This means the ExAC\/gnomAD data at this genomic position has technical artifacts that make the frequency numbers untrustworthy \u2014 can&#8217;t use population frequency as evidence No literature reports: No experimental data: Clinical Significance for ME At this time, this PLEC variant is considered a finding of uncertain significance that: PROOF: what the report states THE COMPOUND HETEROZYGOUS PICTURE \u2014 ALL VARIANTS TOGETHER Net result: MY skeletal muscle cells have:\u00a0 I WANTED TO SHARE MY RESULTS AND PROOF OF SO THAT IF ANYONE WHO HAS THE SAME EXACT MUTATIONS AS ME PLEASE REACT OUT AS IN THE DATABASE I APPEAR TO BE THE ONLY ONE WITH THE MATERNAL MUTATION WHICH CAN INDICATE MY SYMPTOMS COULD BE DIFFERENT THEN OTHERS AS THIS IS A NOT KNOWN VARIANT\u00a0 Please feel free to comment! Part TWO will come out soon<\/p>\n","protected":false},"author":1,"featured_media":76,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"pagelayer_contact_templates":[],"_pagelayer_content":"","_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[1,23],"tags":[25],"class_list":["post-63","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-my-story","category-ryr1","tag-my-story"],"jetpack_featured_media_url":"https:\/\/fibersandfaith.com\/wp-content\/uploads\/2026\/07\/Gemini_Generated_Image_8yh45j8yh45j8yh4.png","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/fibersandfaith.com\/index.php?rest_route=\/wp\/v2\/posts\/63","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fibersandfaith.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fibersandfaith.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fibersandfaith.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fibersandfaith.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=63"}],"version-history":[{"count":7,"href":"https:\/\/fibersandfaith.com\/index.php?rest_route=\/wp\/v2\/posts\/63\/revisions"}],"predecessor-version":[{"id":75,"href":"https:\/\/fibersandfaith.com\/index.php?rest_route=\/wp\/v2\/posts\/63\/revisions\/75"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/fibersandfaith.com\/index.php?rest_route=\/wp\/v2\/media\/76"}],"wp:attachment":[{"href":"https:\/\/fibersandfaith.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=63"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fibersandfaith.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=63"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fibersandfaith.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=63"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}