NM_000257.4:c.1358G>T

Variant names:

• chr14-23429004-C-A
• rs397516101
• NM_000257.4:c.1358G>T

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.1358G>T​(p.Arg453Leu) variant causes a missense change. 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. R453C) 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 U:1
• Conservation: PhyloP100: 4.92

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, 0.983
• PP5: Variant 14-23429004-C-A is Pathogenic according to our data. Variant chr14-23429004-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 235026.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr14-23429004-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH7	NM_000257.4	c.1358G>T	p.Arg453Leu	missense_variant	Exon 14 of 40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.1358G>T	p.Arg453Leu	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.1358G>T	p.Arg453Leu	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: Likely pathogenic

Submissions summary: Pathogenic:3 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypertrophic cardiomyopathy Pathogenic:2

Apr 24, 2023

All of Us Research Program, National Institutes of Health

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces arginine with leucine at codon 453 of the MYH7 protein. This variant is found within a highly conserved region of the myosin head domain. Missense variants in this region have been shown to be significantly overrepresented in individuals with hypertrophic cardiomyopathy (PMID: 27532257). Computational prediction suggests that this variant may have deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in at least one individual affected with hypertrophic cardiomyopathy (PMID: 25351510, 33495597). This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). Different variants occurring at the same codon: p.Arg453Cys, p.Arg453His, and p.Arg453Ser, are well documented pathogenic mutations (Clinvar variation ID: 14089, 42838, 14129), indicating that arginine at this position is important for MYH7 protein function. Based on the available evidence, this variant is classified as Likely Pathogenic. -

Sep 19, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 453 of the MYH7 protein (p.Arg453Leu). This missense change has been observed in individual(s) with clinical features of MYH7-related conditions (PMID: 21520333). ClinVar contains an entry for this variant (Variation ID: 235026). 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. This variant disrupts the p.Arg453 amino acid residue in MYH7. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 11133230, 12975413, 17599605, 24093860, 24111713; 20031618 23283745). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Cardiovascular phenotype Pathogenic:1

Dec 03, 2024

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R453L variant (also known as c.1358G>T), located in coding exon 12 of the MYH7 gene, results from a G to T substitution at nucleotide position 1358. The arginine at codon 453 is replaced by leucine, an amino acid with dissimilar properties. This variant was reported in individual(s) with features consistent with hypertrophic cardiomyopathy (HCM) (Lopes LR et al. Heart, 2015 Feb;101:294-301; Harper AR et al. Nat Genet, 2021 02;53:135-142; Ambry internal data). This alteration is located in the myosin head domain, which contains a statistically significant clustering of pathogenic missense variants (Homburger JR et al. Proc Natl Acad Sci U S A, 2016 06;113:6701-6; Walsh R et al. Genet Med, 2017 02;19:192-203; Ambry internal data). In addition, Other variant(s) at the same codon, p.R453H (c.1358G>T), have been reported in association with HCM (Frazier A et al. Pediatr Cardiol, 2008 Jul;29:846-50; Walsh R et al. Genet. Med., 2017 02;19:192-203). This variant is considered to be rare based on population 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. -

not specified Uncertain:1

Jun 02, 2015

Stanford Center for Inherited Cardiovascular Disease, Stanford University

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

Note this variant was found in clinical genetic testing performed by one or more labs who may also submit to ClinVar. Thus any internal case data may overlap with the internal case data of other labs. The interpretation reviewed below is that of the Stanford Center for Inherited Cardiovascular Disease. p.Arg453Leu in MYH7 Based on the lack of data on this variant, we consider it a variant of uncertain significance. The online cardiogenomics database (curated by the Seidman group) notes that this variant was reported online by Haluza et al in 2000. I wasn’t able to find any further details or additional reports. The arginine at codon 453 is conserved across species, as are neighboring variants. In silico analysis with PolyPhen-2 predicts the variant to be probably damaging. There are two other variants at this codon (p.Arg453Cys, p.Arg453His). There is strong evidence supporting the pathogenicity of p.Arg453Cys and we consider it very likely disease causing. We currently classify p.Arg453His as likely disease causing. Variants at a nearby codon have been reported in association with cardiomyopathy (p.Lys450Glu, p.Lys450Thr). There is no variation at codon 453 listed in the NHLBI Exome Sequencing Project dataset, which currently includes variant calls on ~5000 Caucasian and African American individuals (as of 1/14/2012). There is also no variation at this codon listed in dbSNP or 1000 genomes (as of 1/14/2012). ***The variant was not observed in published controls: ***. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.90	D
Eigen	Pathogenic	0.73
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.97	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Uncertain	2.8	M
PrimateAI	Uncertain	0.79	T
PROVEAN	Pathogenic	-6.3	D
REVEL	Pathogenic	0.87
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.019	D
Polyphen		1.0	D
Vest4		0.93
MutPred		0.84		Gain of stability (P = 0.0197);
MVP		0.98
MPC		2.3
ClinPred		0.99	D
GERP RS		4.2
Varity_R		0.93
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: rs397516101; hg19: chr14-23898213;