Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1PM2_SupportingPM5PP2PP3_StrongPP5_Very_Strong
The NM_000257(MYH7):c.1208G>T(p.Arg403Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD Genomes project. In-silico tool predicts a pathogenic outcome for this variant. 13/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R403Q) has been classified as Pathogenic.
Verdict is Pathogenic. Variant got 18 ACMG points.
GnomAD3 genomesCov.: 32
Submissions by phenotype
|Pathogenic, criteria provided, single submitter||clinical testing||GeneDx||May 28, 2020||Not observed in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 30847666, 31006259, 27532257, 15386449, 12707239, 18227814, 24566549, 7731997, 7848420, 8254035) -|
|Likely pathogenic, no assertion criteria provided||clinical testing||Stanford Center for Inherited Cardiovascular Disease, Stanford University||Jun 16, 2015||Note this variant was found in clinical genetic testing performed by one or more labs who may also submit to ClinVar. Thus any internal case data may overlap with the internal case data of other labs. The interpretation reviewed below is that of the Stanford Center for Inherited Cardiovascular Disease. p.Arg403Leu (c.1208G>T) in MYH7 Based on the data reviewed below we consider this variant likely disease-associated. The variant has been seen in at least 3 unrelated cases of HCM with strong segregation data. The variant was first reported by Dausse et al (1993) in a large kindred in which linkage studies including 11 affected relatives pointed towards MYH7. Sequencing of MYH7 identified p.Arg403Leu and its presence was confirmed in 6 affected individuals. A subsequent publication that included some of the same authors reported an additional family that appears to be distinct from the initial report (Al-Mahdawi et al 1994). Three affected individuals and one obligate carrier carried p.Arg403Leu. Richard et al (2003) reported the variant in one individual with HCM. In silico analysis with PolyPhen-2 predicts the variant to be probably damaging. The arginine at codon 403 is conserved across species, as are neighboring amino acids. Other variants have been reported in association with disease at this codon (p.Arg403Gln and p.Arg403Trp, both very likely disease cuausing) and nearby codons (p.Arg404Leu, p.Arg404Met, p.Arg406Met, p.Arg407Val). Moolman et al (1993) noted that there is a CpG doublet at codon 403 which may likely makes it susceptible to mutation. In total the variant has not been seen in 5150 published controls and publicly available population datsets. There is no variation at codon 403 listed in the NHLBI Exome Sequencing Project dataset, which currently includes variant calls on ~5000 Caucasian and African American individuals (as of 1/14/2012). There is also no variation at this codon listed in 1000 genomes (as of 1/14/2012). p.Arg403Gln is not listed in dbSNP (as of 1/14/2012). The variant was not observed in the following published control samples: 50 (Al-Mahdawi et al 1994), 100 (Richard et al 2003). -|
|Pathogenic, criteria provided, single submitter||clinical testing||Invitae||Aug 28, 2021||This sequence change replaces arginine with leucine at codon 403 of the MYH7 protein (p.Arg403Leu). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and leucine. This variant is not present in population databases (ExAC no frequency). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 8254035, 27532257). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 14101). 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: "Probably Damaging"; Align-GVGD: "Class C0"). 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). For these reasons, this variant has been classified as Pathogenic. -|
|Pathogenic, criteria provided, single submitter||clinical testing||Ambry Genetics||Jul 23, 2020||The p.R403L pathogenic mutation (also known as c.1208G>T), located in coding exon 11 of the MYH7 gene, results from a G to T substitution at nucleotide position 1208. The arginine at codon 403 is replaced by leucine, an amino acid with dissimilar properties, and is located in the head domain. This variant has been reported in several unrelated individuals with hypertrophic cardiomyopathy (HCM), and has been reported to segregate with disease in families (Dausse E et al. J. Clin. Invest., 1993 Dec;92:2807-13; al-Mahdawi S et al. Br Heart J, 1994 Aug;72:105-11; Santos S et al. BMC Med. Genet. 2012 Mar;13:17; Walsh R et al. Genet. Med., 2017 02;19:192-203; Cui H et al. Orphanet J Rare Dis. 2019 11;14(1):252; Norrish G et al. Circulation, 2019 07;140:184-192). In addition, other pathogenic variants affecting this codon (p.R403Q, c.1208G>A and p.R403W, c.1207C>T) have also been reported in association with HCM (Dausse E et al. J. Clin. Invest., 1993 Dec;92:2807-13; Van Driest SL et al. J. Am. Coll. Cardiol., 2004 Aug;44:602-10). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -|
Hypertrophic cardiomyopathy 1
|Pathogenic, no assertion criteria provided||literature only||OMIM||Dec 01, 1993||- -|
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