rs3218713

Positions:

• chr14-23431468-C-A
• chr14-23431468-C-T

Variant summary

Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000257.4(MYH7):​c.746G>T​(p.Arg249Leu) 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R249Q) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.74

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 19 ACMG points.

• PM1: In a strand (size 8) in uniprot entity MYH7_HUMAN there are 15 pathogenic changes around while only 0 benign (100%) in NM_000257.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr14-23431468-C-T is described in Lovd as [Pathogenic].
• 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.972
• PP5: Variant 14-23431468-C-A is Pathogenic according to our data. Variant chr14-23431468-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 635223.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYH7	NM_000257.4	c.746G>T	p.Arg249Leu	missense_variant	9/40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.746G>T	p.Arg249Leu	missense_variant	8/39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.746G>T	p.Arg249Leu	missense_variant	9/40	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

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Likely pathogenic, no assertion criteria provided

provider interpretation

Stanford Center for Inherited Cardiovascular Disease, Stanford University

Mar 23, 2017

- -

Cardiovascular phenotype Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 01, 2019

The p.R249L variant (also known as c.746G>T), located in coding exon 7 of the MYH7 gene, results from a G to T substitution at nucleotide position 746. The arginine at codon 249 is replaced by leucine, an amino acid with dissimilar properties. Other alterations affecting the same amino acid, p.R249Q (c.746G>A) and p.R249G (c.745C>G), have been reported in association with hypertrophic cardiomyopathy (HCM) and left ventricular non-compaction (LVNC) (Rosenzweig A et al. N. Engl. J. Med. 1991;325:1753-60; Tian T et al. Heart Vessels. 2015;30:258-64). In addition, this variant has been determined to be the result of a de novo mutation or germline mosaicism in one family with an isolated case of restrictive cardiomyopathy (Ambry internal data).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. -

Hypertrophic cardiomyopathy 1 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Mendelics

May 28, 2019

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.47
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.90	D
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.43
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D
M_CAP	Pathogenic	0.98	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.9	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Pathogenic	-5.7	D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0030	D
Polyphen		0.90	P
Vest4		0.89
MutPred		0.79		Gain of catalytic residue at A254 (P = 0);
MVP		0.99
MPC		2.3
ClinPred		0.99	D
GERP RS		3.5
Varity_R		0.91
gMVP		0.96

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.16		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: rs3218713; hg19: chr14-23900677;