rs145677314
Variant summary
Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1PP2PP3
The NM_000257.4(MYH7):c.2359C>T(p.Arg787Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000133 in 1,614,022 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R787H) has been classified as Likely benign.
Frequency
Consequence
NM_000257.4 missense
Scores
Clinical Significance
Conservation
Publications
- dilated cardiomyopathyInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- dilated cardiomyopathy 1SInheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
- hypertrophic cardiomyopathyInheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
- hypertrophic cardiomyopathy 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
- MYH7-related skeletal myopathyInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
- myopathy, myosin storage, autosomal recessiveInheritance: AR Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
- myopathy, myosin storage, autosomal dominantInheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
- congenital myopathy 7A, myosin storage, autosomal dominantInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- Ebstein anomalyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- familial isolated dilated cardiomyopathyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- hyaline body myopathyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- left ventricular noncompactionInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- arrhythmogenic right ventricular cardiomyopathyInheritance: AD Classification: LIMITED Submitted by: ClinGen
- congenital heart diseaseInheritance: AD Classification: LIMITED Submitted by: ClinGen
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ACMG classification
Our verdict: Uncertain_significance. The variant received 4 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| MYH7 | ENST00000355349.4 | c.2359C>T | p.Arg787Cys | missense_variant | Exon 21 of 40 | 1 | NM_000257.4 | ENSP00000347507.3 | ||
| MYH7 | ENST00000713768.1 | c.2359C>T | p.Arg787Cys | missense_variant | Exon 21 of 41 | ENSP00000519070.1 | ||||
| MYH7 | ENST00000713769.1 | c.2359C>T | p.Arg787Cys | missense_variant | Exon 20 of 39 | ENSP00000519071.1 |
Frequencies
GnomAD3 genomes AF: 0.0000855 AC: 13AN: 152130Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000557 AC: 14AN: 251470 AF XY: 0.0000221 show subpopulations
GnomAD4 exome AF: 0.000138 AC: 202AN: 1461892Hom.: 0 Cov.: 33 AF XY: 0.000135 AC XY: 98AN XY: 727246 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000855 AC: 13AN: 152130Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74312 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:4
Identified in a patient with infantile nephropathic cystinosis (INC) and muscle weakness (PMID: 34888877); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Identified in patients with HCM referred for genetic testing at GeneDx and in published literature; at least one patient also harbored an additional cardiogenetic variant (PMID: 18403758, 19150014, 22765922, 27532257, 37652022); This variant is associated with the following publications: (PMID: 28606303, 23299917, 23861362, 25637381, 18403758, 22765922, 27532257, 34542152, 19150014, 29300372, 37652022, 34888877, 37937776) -
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MYH7: PM2 -
Cardiomyopathy Uncertain:3
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This missense variant replaces arginine with cysteine at codon 787 of the MYH7 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in individuals affected with hypertrophic cardiomyopathy (PMID: 18403758, 22765922, 27532257). It has also been reported in an individual affected with neuromuscular disease (PMID: 34888877). This variant has also been identified in 18/282860 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 cysteine at codon 787 of the MYH7 protein. Computational prediction tools indicate that this variant's impact on protein structure and function is inconclusive. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in five individuals affected with hypertrophic cardiomyopathy (PMID: 18403758, 22765922, 27532257). It has also been reported in one individual affected with neuromuscular disease (PMID: 34888877). This variant has also been identified in 18/282860 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. -
not specified Uncertain:2
The p.Arg787Cys variant in MYH7 has been identified in 5 individuals with HCM (G arcia-Castro 2009, Coto 2012, Walsh 2017), 1 child with HCM, who also carried th e p.Arg97Cys variant in ACTC (Morita 2008), 1 adult with premature atrial contr actions (Ng 2013), and in 1 adult with ARVC, who carried another likely disease causing variant (LMM data). This variant has also been identified in 11/126688 E uropean chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.br oadinstitute.org; dbSNP rs145677314). Arginine (Arg) at position 787 is not wel l conserved in mammals or evolutionarily distant species and the change to cyste ine (Cys) is present in 2 mammals (megabat and black flying fox). Additional com putational prediction tools do not provide strong support for or against an impa ct to the protein. In summary, the clinical significance of the p.Arg787Cys vari ant is uncertain. -
Variant summary: MYH7 c.2359C>T (p.Arg787Cys) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 5.6e-05 in 251470 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in MYH7 causing Hypertrophic Cardiomyopathy (5.6e-05 vs 0.0013), allowing no conclusion about variant significance. c.2359C>T has been reported in the literature in individuals affected with Hypertrophic Cardiomyopathy without strong evidence of causality (e.g. Morita_2008, Garcia-Castro_2009, Coto_2012, Gomez_2017, Walsh_2017, Kurzlechner_2022, McGurk_2023). These reports do not provide unequivocal conclusions about association of the variant with Hypertrophic Cardiomyopathy. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 18403758, 19150014, 27532257, 22765922, 28356264, 35629155, 37652022). ClinVar contains an entry for this variant (Variation ID: 161327). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Hypertrophic cardiomyopathy Uncertain:2
This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 787 of the MYH7 protein (p.Arg787Cys). This variant is present in population databases (rs145677314, gnomAD 0.009%). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 18403758, 22765922, 27532257). ClinVar contains an entry for this variant (Variation ID: 161327). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C65"). This variant is found within a region of MYH7 between codons 181 and 937 that contains the majority of the myosin head domain. Missense variants in this region have been shown to be significantly overrepresented in individuals with hypertrophic cardiomyopathy (PMID: 27532257). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
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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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Primary familial hypertrophic cardiomyopathy Uncertain:1
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Cardiovascular phenotype Uncertain:1
The p.R787C variant (also known as c.2359C>T), located in coding exon 19 of the MYH7 gene, results from a C to T substitution at nucleotide position 2359. The arginine at codon 787 is replaced by cysteine, an amino acid with highly dissimilar properties. This alteration is located in the myosin head domain, which contains a statistically significant clustering of pathogenic missense variants (Homburger JR et al. Proc Natl Acad Sci U S A, 2016 06;113:6701-6; Walsh R et al. Genet Med, 2017 02;19:192-203; Ambry internal data). This variant has been reported in individual(s) in hypertrophic cardiomyopathy (HCM) cohorts, but clinical details were limited (García-Castro M et al. Rev Esp Cardiol, 2009 Jan;62:48-56; Tsoutsman T et al. Clin. Exp. Pharmacol. Physiol., 2008 Nov;35:1349-57; Coto E et al. J Mol Diagn, 2012 Sep;14:518-24; Walsh R et al. Genet. Med., 2017 02;19:192-203). This amino acid position is well 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. -
Hypertrophic cardiomyopathy 1 Uncertain:1
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases did not allow this variant to be ruled in or out of causing disease. Therefore, this variant is classified as a variant of unknown significance. -
Dilated cardiomyopathy 1S Benign:1
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -
MYH7-related skeletal myopathy Benign:1
This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases allowed determination this variant is unlikely to cause disease. Therefore, this variant is classified as likely benign. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at