chr14-23429044-C-T

Position:

• chr14-23429044-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PS4_Supporting PM2 PM1 PP3 PP1

This summary comes from the ClinGen Evidence Repository: The c.1318G>A (p.Val440Met) variant in MYH7 has been reported in at least 3 individuals with HCM (PS4_Supporting; Van Driest 2004 PMID:15358028; Bos 2014 PMID:24793961; Walsh 2017 PMID:27532257; LMM pers comm.; OMGL pers comm.) and 1 individual with RCM (Invitae pers comm.). This variant segregated with HCM in 3 affected relatives from 3 families (PP1; LMM pers comm.; OMGL pers comm.). This variant was absent from large population studies (PM2; http://gnomad.broadinstitute.org, v2.1.1). This variant lies in the head region of the protein (aa 181-937) and missense variants in this region are statistically more likely to be disease-associated (PM1; Walsh 2017 PMID:27532257). Computational prediction tools and conservation analysis suggest that this variant may impact the protein (PP3). In summary, this variant meets criteria to be classified as likely pathogenic for hypertrophic cardiomyopathy in an autosomal dominant manner. ACMG/AMP Criteria applied: PS4_Supporting; PP1; PM2; PM1; PP3. LINK:https://erepo.genome.network/evrepo/ui/classification/CA010537/MONDO:0005045/002

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYH7 ENST00000355349.4 missense
• Clinical Significance: Likely pathogenic reviewed by expert panel P:3 U:1
• Conservation: PhyloP100: 4.83

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 Likely_pathogenic. Variant got 7 ACMG points.

• PS4: For more information check the summary or visit ClinGen Evidence Repository.
• PM1: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PP1: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYH7	NM_000257.4	c.1318G>A	p.Val440Met	missense_variant	14/40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.1318G>A	p.Val440Met	missense_variant	13/39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.1318G>A	p.Val440Met	missense_variant	14/40	1	NM_000257.4	ENSP00000347507	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:3 Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Hypertrophic cardiomyopathy Pathogenic:2 Uncertain:1

Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Nov 13, 2023	This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 440 of the MYH7 protein (p.Val440Met). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 15358028, 27532257, 33673806). ClinVar contains an entry for this variant (Variation ID: 42835). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt MYH7 protein function with a positive predictive value of 95%. 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. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Nov 06, 2017	The p.Val440Met variant in MYH7 has been reported in 5 individuals with HCM (Van Driest 2004; Walsh 2016) and segregated with disease in 2 affected relatives fr om 2 families. This variant was absent from large population studies. This varia nt was predicted to be pathogenic using a computational tool clinically validate d by our laboratory. This tool's pathogenic prediction is estimated to be correc t 94% of the time (Jordan 2011). This variant lies in the head region of the pro tein. Missense variants in this region have been reported and statistically indi cated to be more likely to cause disease (Walsh 2016). In summary, although addi tional studies are required to fully establish its clinical significance, the p. Val440Met variant is likely pathogenic. -
Likely pathogenic, reviewed by expert panel	curation	ClinGen Cardiomyopathy Variant Curation Expert Panel	Aug 12, 2020	The c.1318G>A (p.Val440Met) variant in MYH7 has been reported in at least 3 individuals with HCM (PS4_Supporting; Van Driest 2004 PMID:15358028; Bos 2014 PMID:24793961; Walsh 2017 PMID:27532257; LMM pers comm.; OMGL pers comm.) and 1 individual with RCM (Invitae pers comm.). This variant segregated with HCM in 3 affected relatives from 3 families (PP1; LMM pers comm.; OMGL pers comm.). This variant was absent from large population studies (PM2; http://gnomad.broadinstitute.org, v2.1.1). This variant lies in the head region of the protein (aa 181-937) and missense variants in this region are statistically more likely to be disease-associated (PM1; Walsh 2017 PMID:27532257). Computational prediction tools and conservation analysis suggest that this variant may impact the protein (PP3). In summary, this variant meets criteria to be classified as likely pathogenic for hypertrophic cardiomyopathy in an autosomal dominant manner. ACMG/AMP Criteria applied: PS4_Supporting; PP1; PM2; PM1; PP3. -

Primary familial hypertrophic cardiomyopathy Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Dec 22, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.96	D
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.99	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.1	H
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.67	T
PROVEAN	Uncertain	-2.7	D
REVEL	Pathogenic	0.88
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.89
MutPred		0.77		Gain of catalytic residue at R442 (P = 0.0017);
MVP		0.97
MPC		2.1
ClinPred		1.0	D
GERP RS		4.2
Varity_R		0.82
gMVP		0.99

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: rs397516098; hg19: chr14-23898253;