chr14-23415258-C-A

Variant names:

• chr14-23415258-C-A
• rs267606909
• NM_000257.4:c.5296G>T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PM5 PP2

The NM_000257.4(MYH7):​c.5296G>T​(p.Ala1766Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A1766T) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.54

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]

ENSG00000258444 (HGNC:):

MHRT (HGNC:51291): (myosin heavy chain associated RNA transcript) This gene encodes a spliced long non-coding RNA that may act as a cardioprotective agent in the heart. Based on a study of a similar gene in mouse, the encoded transcript may regulate chromatin remodeling by acting as a decoy to the BRG1 chromatin repressor complex thus preventing it from binding to its genomic targets. Blocking the actions of BRG1 could be crucial in protecting the heart from pathological hypertrophy. [provided by RefSeq, Dec 2014]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a helix (size 38) in uniprot entity MYH7_HUMAN there are 10 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 chr14-23415258-C-T is described in Lovd as [Pathogenic].
• 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH7	NM_000257.4	c.5296G>T	p.Ala1766Ser	missense_variant	Exon 37 of 40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.5296G>T	p.Ala1766Ser	missense_variant	Exon 36 of 39		NP_001393933.1
MHRT	NR_126491.1	n.-192C>A		upstream_gene_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.5296G>T	p.Ala1766Ser	missense_variant	Exon 37 of 40	1	NM_000257.4	ENSP00000347507.3
ENSG00000258444	ENST00000557368.1	n.-81C>A		upstream_gene_variant		3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251486 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135920

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.65
CardioboostCm	Uncertain	0.19
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.030
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.68	D
Eigen	Pathogenic	0.77
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.90	D
M_CAP	Pathogenic	0.64	D
MetaRNN	Uncertain	0.73	D
MetaSVM	Uncertain	0.21	D
MutationAssessor	Uncertain	2.4	M
PrimateAI	Pathogenic	0.85	D
PROVEAN	Benign	-1.7	N
REVEL	Uncertain	0.52
Sift	Benign	0.12	T
Sift4G	Benign	0.21	T
Polyphen		1.0	D
Vest4		0.55
MutPred		0.39		Gain of phosphorylation at A1766 (P = 0.0142);
MVP		0.86
MPC		1.5
ClinPred		0.98	D
GERP RS		5.3
Varity_R		0.34
gMVP		0.90

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: rs267606909; hg19: chr14-23884467;