rs370310929
Variant summary
Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM5PP2PP3_Moderate
The NM_000257.4(MYH7):c.1315A>T(p.Met439Leu) variant causes a missense change. The variant allele was found at a frequency of 0.0000112 in 1,614,080 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M439V) has been classified as Likely pathogenic.
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: Likely_pathogenic. The variant received 7 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| MYH7 | ENST00000355349.4 | c.1315A>T | p.Met439Leu | missense_variant | Exon 14 of 40 | 1 | NM_000257.4 | ENSP00000347507.3 | ||
| MYH7 | ENST00000713768.1 | c.1315A>T | p.Met439Leu | missense_variant | Exon 14 of 41 | ENSP00000519070.1 | ||||
| MYH7 | ENST00000713769.1 | c.1315A>T | p.Met439Leu | missense_variant | Exon 13 of 39 | ENSP00000519071.1 |
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152186Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000795 AC: 2AN: 251494 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.0000116 AC: 17AN: 1461894Hom.: 0 Cov.: 33 AF XY: 0.0000138 AC XY: 10AN XY: 727248 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152186Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74338 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:3
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Hypertrophic cardiomyopathy Pathogenic:1Uncertain:1
The Met439Leu variant has not been reported in the literature. Methionine (Met) at position 439 is highly conserved across several evolutionary distant species. In addition, this variant was predicted to be pathogenic using a novel computational tool (a customized sarcomere-specific PolyPhen tool, which was validated using a set of cardiomyopathy variants with well-established clinical significance). This tool's pathogenic prediction is estimated to be correct 94% of the time, which suggests but does not prove that this variant is pathogenic. Finally, this individual's racial origin is reported to be Caucasian and the Met439Leu variant has not been identified in over 1675 Caucasian probands (3350 chromosomes) tested by our laboratory. Although we cannot exclude the possibility that this variant could be benign, this low frequency, high conservation and computational prediction together increase the likelihood that it is pathogenic. -
This sequence change replaces methionine with leucine at codon 439 of the MYH7 protein (p.Met439Leu). The methionine residue is highly conserved and there is a small physicochemical difference between methionine and leucine. This variant is present in population databases (rs370310929, ExAC 0.003%). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 27532257). ClinVar contains an entry for this variant (Variation ID: 177948). 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 C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -
Cardiomyopathy Uncertain:1
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Cardiovascular phenotype Uncertain:1
The p.M439L variant (also known as c.1315A>T), located in coding exon 12 of the MYH7 gene, results from an A to T substitution at nucleotide position 1315. The methionine at codon 439 is replaced by leucine, an amino acid with highly similar 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 alteration has been reported in hypertrophic cardiomyopathy (HCM) cohorts (Walsh R et al. Genet Med, 2017 Feb;19:192-203; van Lint FHM et al. Neth Heart J, 2019 Jun;27:304-309; Harper AR et al. Nat Genet, 2021 Feb;53:135-142). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at