rs371855540
Variant summary
Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PP2PP3
The NM_000257.4(MYH7):c.5459G>A(p.Arg1820Gln) variant causes a missense change. The variant allele was found at a frequency of 0.0000186 in 1,613,876 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000257.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 2 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000394 AC: 6AN: 152248Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000199 AC: 5AN: 251346Hom.: 0 AF XY: 0.0000147 AC XY: 2AN XY: 135868
GnomAD4 exome AF: 0.0000164 AC: 24AN: 1461628Hom.: 0 Cov.: 34 AF XY: 0.0000138 AC XY: 10AN XY: 727148
GnomAD4 genome AF: 0.0000394 AC: 6AN: 152248Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74376
ClinVar
Submissions by phenotype
Cardiomyopathy Uncertain:3
This missense variant replaces arginine with glutamine at codon 1820 of the MYH7 protein. Computational prediction tools indicate that this variant has a deleterious impact on protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with distal myopathy and hypertrophic cardiomyopathy (PMID: 27282841), and in an individual affected with arrhythmogenic right ventricular cardiomyopathy (PMID: 30177324). This variant has been identified in 5/251346 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
This missense variant replaces arginine with glutamine at codon 1820 of the MYH7 protein. Computational prediction tools indicate that this variant has a deleterious impact on protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with distal myopathy and hypertrophic cardiomyopathy (PMID: 27282841), and in an individual affected with arrhythmogenic right ventricular cardiomyopathy (PMID: 30177324). This variant has been identified in 5/251346 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
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Hypertrophic cardiomyopathy Pathogenic:1
This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 1820 of the MYH7 protein (p.Arg1820Gln). This variant is present in population databases (rs371855540, gnomAD 0.006%). This missense change has been observed in individual(s) with autosomal recessive MYH7-related conditions (PMID: 27282841). This variant has been reported in individual(s) with autosomal dominant hypertrophic cardiomyopathy (PMID: 37652022; internal data); however, the role of the variant in this condition is currently unclear. ClinVar contains an entry for this variant (Variation ID: 419278). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt MYH7 protein function with a positive predictive value of 95%. This variant disrupts the p.Arg1820 amino acid residue in MYH7. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 25666907). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
not specified Uncertain:1
Variant classified as Uncertain Significance - Favor Pathogenic. The p.Arg1820Gln variant in MYH7 has been reported in 1 individual with both hypertrophic cardiomyopathy and distal myopathy as well as in one sibling with only myopathy; however, both individuals as well as a third affected sibling had an additional pathogenic variant sufficient to cause distal myopathy, but which has not been previously associated with cardiomyopathy (Brand 2016). It has also been identified in 1 individual with HCM (LMM data) and has been identified in 5/251346 chromosomes by gnomAD (https://gnomad.broadinstitute.org). It has also been reported in ClinVar (Variation ID #419278). Computational prediction tools and conservation analysis suggest that the p.Arg1820Gln variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, while there is some suspicion for a pathogenic role, the clinical significance of this variant is uncertain. ACMG/AMP Criteria Applied: PM2, PS4_Supporting, PP3. -
Congenital myopathy with fiber type disproportion;C1834481:Dilated cardiomyopathy 1S;C1842160:Myosin storage myopathy;C1850709:Myopathy, myosin storage, autosomal recessive;C3495498:Hypertrophic cardiomyopathy 1;C4552004:MYH7-related skeletal myopathy Uncertain:1
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not provided Uncertain:1
The R1820Q variant of uncertain significance in the MYH7 gene has been previously reported in two sisters with distal myopathy, one of whom developed supraventricular tachycardia and HCM at the age of 64 years, however, it was absent from a third sibling with isolated distal myopathy (Brand et al., 2016). Brand et al. (2016) reported that all three siblings in this family also harbored a pathogenic missense variant in the TIA1 gene, which is associated with Welander distal myopathy, and this family had a paternal family history of cardiac disease but further segregation studies of the R1820Q variant were not reported. The R1820Q variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). Furthermore, R1820Q is a semi-conservative amino acid substitution, which may impact secondary protein structure as these residues differ in some properties, and this substitution occurs at a position that is conserved across species. Nevertheless, in silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. Additionally, although a missense variant at the same residue in the MYH7 gene (R1820W) has been reported in the Human Gene Mutation Database in association with myopathy (Stenson et al., 2014), the clinical significance of this variant also remains to be definitively determined. -
Cardiovascular phenotype Uncertain:1
The p.R1820Q variant (also known as c.5459G>A), located in coding exon 35 of the MYH7 gene, results from a G to A substitution at nucleotide position 5459. The arginine at codon 1820 is replaced by glutamine, an amino acid with highly similar properties. This alteration was detected in two of three siblings in a family, all of whom also carried the TIA1 p.E384K alteration. Phenotypes of the two siblings with both alterations included progressive asymmetric distal limb weakness, mild distal myopathy, supraventricular tachycardia and hypertrophic cardiomyopathy. The third sibling who only carried the TIA1 alteration had isolated distal myopathy (Brand P et al. Neuromuscul. Disord., 2016 08;26:511-5). This variant has also been reported in an individual with arrhythmogenic right ventricular cardiomyopathy (ARVC) and co-occurring DSG2 variants, as well as in an exome cohort with limited clinical details (Homburger JR et al. Proc Natl Acad Sci U S A, 2016 06;113:6701-6; Lin Y et al. J Electrocardiol Jun;51:837-843). This alteration also been reported in association with transposition of the great arteries (Blue GM et al. Am Heart J, 2022 Feb;244:1-13). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at