14-23429005-G-T

Variant names:

• chr14-23429005-G-T
• rs121913625
• NM_000257.4:c.1357C>A

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000257.4(MYH7):​c.1357C>A​(p.Arg453Ser) variant causes a missense change involving the alteration of a non-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 Pathogenic (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R453C) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Pathogenic reviewed by expert panel P:2 U:1
• Conservation: PhyloP100: 1.75

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 17 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr14-23429005-G-A 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.973
• PP5: Variant 14-23429005-G-T is Pathogenic according to our data. Variant chr14-23429005-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 14129.Status of the report is reviewed_by_expert_panel, 3 stars. Variant chr14-23429005-G-T is described in Lovd as [Pathogenic]. Variant chr14-23429005-G-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH7	NM_000257.4	c.1357C>A	p.Arg453Ser	missense_variant	Exon 14 of 40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.1357C>A	p.Arg453Ser	missense_variant	Exon 13 of 39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.1357C>A	p.Arg453Ser	missense_variant	Exon 14 of 40	1	NM_000257.4	ENSP00000347507.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2 Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Hypertrophic cardiomyopathy Pathogenic:1

Jun 16, 2021

ClinGen Cardiomyopathy Variant Curation Expert Panel

Significance: Pathogenic

Review Status: reviewed by expert panel

Collection Method: curation

The c.1357C>A (p.Arg453Ser) variant in MYH7 has been identified in 3 individuals with HCM, including 1 individual with early onset HCM (<20 yo; PS4_Supporting; Frazier 2008 PMID:18175163; Walsh 2017 PMID:27532257; Centenary Institute Sydney pers. comm.; LMM pers. comm.) and segregated with disease in 9 affected relatives with HCM from 2 families (PP1_Strong; Centenary Institute Sydney pers. comm.; LMM pers. comm.). This variant was absent from large population studies (PM2; http:/gnomad.broadinstitute.org, v2.1.1). Computational prediction tools and conservation analysis suggest that this variant may impact the protein (PP3). Two different missense variants that have been classified as pathogenic by this expert panel have been previously identified at this codon, which indicate that this residue may be critical to the function of the protein (PM5; c.1358G>T, p.Arg453His - Variation ID 42838 and c.1357C>T, p.Arg453Cys - Variation ID 14089). 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); however, because the other pathogenic variants at this codon were used to establish this enrichment, PM1 cannot be used in combination with PM5. In summary, this variant meets criteria to be classified as likely pathogenic for hypertrophic cardiomyopathy in an autosomal dominant manner. MYH7-specific ACMG/AMP criteria applied (Kelly 2018 PMID:29300372): PS4_Supporting; PP1_Strong; PM2; PP3; PM5. -

Hypertrophic cardiomyopathy 1 Pathogenic:1

Jul 01, 2008

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

not specified Uncertain:1

Mar 07, 2014

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

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

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.30
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.87	D
Eigen	Uncertain	0.42
Eigen_PC	Uncertain	0.36
FATHMM_MKL	Benign	0.61	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Uncertain	0.48	D
MutationAssessor	Benign	1.6	L
PrimateAI	Uncertain	0.77	T
PROVEAN	Pathogenic	-5.4	D
REVEL	Pathogenic	0.76
Sift	Pathogenic	0.0	D
Sift4G	Benign	0.093	T
Polyphen		1.0	D
Vest4		0.84
MutPred		0.81		Gain of catalytic residue at Q454 (P = 0.0057);
MVP		0.96
MPC		2.2
ClinPred		0.99	D
GERP RS		4.2
Varity_R		0.92
gMVP		0.98

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: rs121913625; hg19: chr14-23898214;