chr14-23428642-T-C

Variant names:

• chr14-23428642-T-C
• rs727504236
• NM_000257.4:c.1436A>G

Variant summary

Our verdict is Pathogenic. Variant got 15 ACMG points: 15P and 0B. PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_000257.4(MYH7):​c.1436A>G​(p.Asn479Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 7.76

Genes affected

MYH7 (HGNC:7577): (myosin heavy chain 7) Muscle myosin is a hexameric protein containing 2 heavy chain subunits, 2 alkali light chain subunits, and 2 regulatory light chain subunits. This gene encodes the beta (or slow) heavy chain subunit of cardiac myosin. It is expressed predominantly in normal human ventricle. It is also expressed in skeletal muscle tissues rich in slow-twitch type I muscle fibers. Changes in the relative abundance of this protein and the alpha (or fast) heavy subunit of cardiac myosin correlate with the contractile velocity of cardiac muscle. Its expression is also altered during thyroid hormone depletion and hemodynamic overloading. Mutations in this gene are associated with familial hypertrophic cardiomyopathy, myosin storage myopathy, dilated cardiomyopathy, and Laing distal myopathy. [provided by RefSeq, May 2022]

ACMG classification

Verdict is Pathogenic. Variant got 15 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the MYH7 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 341 curated pathogenic missense variants (we use a threshold of 10). The gene has 16 curated benign missense variants. Gene score misZ: 3.9329 (above the threshold of 3.09). Trascript score misZ: 6.7889 (above the threshold of 3.09). GenCC associations: The gene is linked to hyaline body myopathy, MYH7-related skeletal myopathy, dilated cardiomyopathy 1S, congenital myopathy 7A, myosin storage, autosomal dominant, dilated cardiomyopathy, left ventricular noncompaction, myopathy, myosin storage, autosomal dominant, hypertrophic cardiomyopathy, congenital heart disease, Ebstein anomaly, arrhythmogenic right ventricular cardiomyopathy, myopathy, myosin storage, autosomal recessive, hypertrophic cardiomyopathy 1, familial isolated dilated cardiomyopathy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.985
• PP5: Variant 14-23428642-T-C is Pathogenic according to our data. Variant chr14-23428642-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 177623.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr14-23428642-T-C is described in Lovd as [Pathogenic]. Variant chr14-23428642-T-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH7	NM_000257.4	c.1436A>G	p.Asn479Ser	missense_variant	Exon 15 of 40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.1436A>G	p.Asn479Ser	missense_variant	Exon 14 of 39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.1436A>G	p.Asn479Ser	missense_variant	Exon 15 of 40	1	NM_000257.4	ENSP00000347507.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypertrophic cardiomyopathy Pathogenic:3

Dec 12, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 479 of the MYH7 protein (p.Asn479Ser). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with clinical features of hypertrophic cardiomyopathy (PMID: 12707239, 12820698, 27532257, 28356264). ClinVar contains an entry for this variant (Variation ID: 177623). 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 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. -

Mar 15, 2018

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

proposed classification - variant undergoing re-assessment, contact laboratory -

Feb 09, 2017

Center for Human Genetics, University of Leuven

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ACMG score pathogenic -

not provided Pathogenic:1

Mar 26, 2024

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Identified in patients with HCM in published literature (PMID: 12707239, 27532257, 12820698, 20800588, 28356264, 37652022, 29255176); Not observed at significant frequency in large population cohorts (gnomAD); 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: 12707239, 27532257, 31513939, 12820698, 20800588, 28356264, 28606303, 29300372, 37652022, 29255176) -

MYH7-related disorder Pathogenic:1

Nov 25, 2022

Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ACMG classification criteria: PS4 moderated, PM1 moderated, PM2 moderated, PP3 supporting -

Cardiovascular phenotype Pathogenic:1

Feb 06, 2025

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.N479S variant (also known as c.1436A>G), located in coding exon 13 of the MYH7 gene, results from an A to G substitution at nucleotide position 1436. The asparagine at codon 479 is replaced by serine, 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 detected in a number of individuals with hypertrophic cardiomyopathy and co-segregation has been reported in at least one family (Mohiddin SA et al. Genet. Test., 2003;7:21-7; Richard P et al. Circulation, 2003 May;107:2227-32; Gómez J et al. Circ Cardiovasc Genet, 2017 Apr;10:e001584; Walsh R et al. Genet. Med., 2017 02;19:192-203; Robyns T et al. Eur J Hum Genet, 2017 12;25:1313-1323; Robyns T et al. Eur J Med Genet, 2020 Mar;63:103754; Invitae pers. comm.). This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.91
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.28	D
BayesDel_noAF	Pathogenic	0.17
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.95	D
Eigen	Uncertain	0.42
Eigen_PC	Uncertain	0.43
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.99	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.2	D
MutationAssessor	Pathogenic	3.6	H
PrimateAI	Uncertain	0.77	T
PROVEAN	Uncertain	-4.1	D
REVEL	Pathogenic	0.91
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.030	D
Polyphen		0.12	B
Vest4		0.94
MutPred		0.86		Gain of catalytic residue at I478 (P = 0.0039);
MVP		0.99
MPC		1.2
ClinPred		0.98	D
GERP RS		4.2
Varity_R		0.79
gMVP		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs727504236; hg19: chr14-23897851;