NM_000257.4:c.2348G>T

Variant names:

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 7P and 1B. PM1PM2PM5PP2BP4

The NM_000257.4(MYH7):c.2348G>T(p.Arg783Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R783H) has been classified as Pathogenic.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

MYH7
NM_000257.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:6

Conservation

PhyloP100: -0.131

Variant links:

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]

MYH7 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

PM1

In a helix (size 20) in uniprot entity MYH7_HUMAN there are 22 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 chr14-23425357-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.

BP4

Computational evidence support a benign effect (MetaRNN=0.29085296).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH7	NM_000257.4 link	c.2348G>T	p.Arg783Leu	missense_variant	Exon 21 of 40	ENST00000355349.4	NP_000248.2	P12883
MYH7	NM_001407004.1 link	c.2348G>T	p.Arg783Leu	missense_variant	Exon 20 of 39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4 link	c.2348G>T	p.Arg783Leu	missense_variant	Exon 21 of 40	1	NM_000257.4	ENSP00000347507.3		P12883

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000795

AC:

AN:

251466

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135906

show subpopulations

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:

0.000163

GnomAD4 exome

AF:

0.00000274

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727242

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000180

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

Cov.:

Bravo

AF:

0.0000189

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cardiomyopathy

Uncertain:2

Apr 25, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces arginine with leucine at codon 783 of the MYH7 protein. Computational prediction tools indicate that this variant has a neutral impact on protein structure and function. To our knowledge, functional studies have not been reported for this variant. This variant has been reported in one individual affected with sudden arrhythmic death (PMID: 26498160), in one individual affected with sudden cardiac death (PMID: 34984526), and in one individual affected with familial amyloid polyneuropathy and left ventricular hypertrophy who also carried a pathogenic variant in the TTR gene (PMID: 34817018). This variant has been identified in 2/251466 chromosomes in the general population by the Genome Aggregation Database (gnomAD). Different variants affecting the same codon, p.Arg783His and p.Arg783Pro, are considered to be disease-causing (ClinVar variation ID: 193999, 42895), suggesting that arginine at this position is important for MYH7 protein function. 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. -

Apr 27, 2020

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces arginine with leucine at codon 783 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 been identified in 2/251466 chromosomes 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. -

not provided

Uncertain:2

May 12, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Identified in a patient who died suddenly at 50 years of age and was found to have left ventricular hypertrophy (Fadoni et al., 2022); Identified in a patient with familial amyloid polyneuropathy who also harbored a pathogenic variant in the TTR gene (Rodrigues et al., 2021); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 27532257, 34984526, 34817018, 29300372) -

Aug 01, 2023

Revvity Omics, Revvity

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hypertrophic cardiomyopathy

Uncertain:1

Oct 24, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 783 of the MYH7 protein (p.Arg783Leu). This variant is present in population databases (no rsID available, gnomAD 0.003%). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy and/or sudden cardiac death, clinical features of autosomal dominant MYH7-related myopathy (PMID: 34984526; internal data). ClinVar contains an entry for this variant (Variation ID: 454355). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on MYH7 protein function. This variant disrupts the p.Arg783 amino acid residue in MYH7. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 21211974). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. -

Cardiovascular phenotype

Uncertain:1

Jan 12, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R783L variant (also known as c.2348G>T), located in coding exon 19 of the MYH7 gene, results from a G to T substitution at nucleotide position 2348. The arginine at codon 783 is replaced by leucine, an amino acid with dissimilar properties. This alteration has been reported in sudden death cohorts (Nunn LM et al. Europace, 2016 Jun;18:888-96; Fadoni J et al. Int J Legal Med, 2022 Mar;136:483-491). Two other alterations at the same codon, p.R783H (c.2348G>A) and p.R783P (c.2348G>C), have been detected in cardiomyopathy cohorts (Walsh R et al. Genet. Med., 2017 Feb;19:192-203). 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). This amino acid position is not well conserved in available vertebrate species, and leucine is the reference amino acid in other vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.18

CardioboostCm

Uncertain

0.20

BayesDel_addAF

Benign

-0.053

BayesDel_noAF

Benign

-0.23

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.56

Eigen

Benign

-0.41

Eigen_PC

Benign

-0.26

FATHMM_MKL

Benign

0.081

LIST_S2

Uncertain

0.89

M_CAP

Pathogenic

0.53

MetaRNN

Benign

0.29

MetaSVM

Uncertain

-0.23

MutationAssessor

Benign

0.33

PrimateAI

Uncertain

0.71

PROVEAN

Uncertain

-2.9

REVEL

Uncertain

0.34

Sift

Benign

0.21

Sift4G

Benign

0.23

Polyphen

0.0

Vest4

0.26

MutPred

0.57

Gain of catalytic residue at R787 (P = 0.0071);

MVP

0.93

MPC

1.2

ClinPred

0.31

GERP RS

4.6

Varity_R

0.46

gMVP

0.96

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over