rs202097576

Positions:

• chr14-23424034-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_000257.4(MYH7):​c.2795T>C​(p.Met932Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 7.32

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 Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_000257.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), MYH7. . Gene score misZ 3.9329 (greater than the threshold 3.09). Trascript score misZ 6.7889 (greater than threshold 3.09). GenCC has associacion of gene with 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYH7	NM_000257.4	c.2795T>C	p.Met932Thr	missense_variant	23/40	ENST00000355349.4
MYH7	NM_001407004.1	c.2795T>C	p.Met932Thr	missense_variant	22/39

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYH7	ENST00000355349.4	c.2795T>C	p.Met932Thr	missense_variant	23/40	1	NM_000257.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cardiomyopathy Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario	Dec 01, 2015	- -
Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Oct 30, 2023	This missense variant replaces methionine with threonine at codon 932 of the MYH7 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has not been identified 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. -

Primary familial hypertrophic cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

research

Biesecker Lab/Clinical Genomics Section, National Institutes of Health

Jun 24, 2013

- -

Hypertrophic cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 19, 2022

This variant disrupts the p.Met932 amino acid residue in MYH7. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 21302287, 28002430). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C65". The threonine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. ClinVar contains an entry for this variant (Variation ID: 191732). This variant has not been reported in the literature in individuals affected with MYH7-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 932 of the MYH7 protein (p.Met932Thr). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.19
CardioboostCm	Benign	0.0067
BayesDel_addAF	Uncertain	0.093	D
BayesDel_noAF	Benign	-0.10
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.81	D
Eigen	Benign	0.16
Eigen_PC	Uncertain	0.26
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Benign	0.60	T
M_CAP	Pathogenic	0.72	D
MetaRNN	Uncertain	0.59	D
MetaSVM	Uncertain	0.029	D
MutationAssessor	Uncertain	2.1	M
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.74	T
PROVEAN	Uncertain	-2.5	D
REVEL	Uncertain	0.45
Sift	Benign	0.058	T
Sift4G	Benign	0.61	T
Polyphen		0.46	P
Vest4		0.40
MutPred		0.43		Gain of phosphorylation at M932 (P = 0.0172);
MVP		0.96
MPC		0.61
ClinPred		0.87	D
GERP RS		4.2
Varity_R		0.27
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: rs202097576; hg19: chr14-23893243;