NM_000257.4:c.221A>G

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1PM2PP2

The NM_000257.4(MYH7):c.221A>G(p.Asp74Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,614,014 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

MYH7
NM_000257.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 1.53

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 Uncertain_significance. Variant got 5 ACMG points.

PM1

In a domain Myosin N-terminal SH3-like (size 49) in uniprot entity MYH7_HUMAN there are 6 pathogenic changes around while only 0 benign (100%) in NM_000257.4

PM2

Very rare variant in population databases, with high coverage;

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 link	c.221A>G	p.Asp74Gly	missense_variant	Exon 4 of 40	ENST00000355349.4	NP_000248.2	P12883
MYH7	NM_001407004.1 link	c.221A>G	p.Asp74Gly	missense_variant	Exon 3 of 39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4 link	c.221A>G	p.Asp74Gly	missense_variant	Exon 4 of 40	1	NM_000257.4	ENSP00000347507.3		P12883

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152126

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727246

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

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:

0.00000270

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152126

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74300

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Dilated cardiomyopathy 1S;C3495498:Hypertrophic cardiomyopathy 1

Uncertain:1

May 30, 2023

New York Genome Center

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.221A>G p.(Asp74Gly) variant identified in the MYH7 gene has not been reported in affected individuals in the literature. It has been deposited to ClinVar database as a Varaint of Uncertain Significance [ClinVar ID:181298]. This variant is found in 1 out of ~590,000 alleles (0 homozygotes) in population databases (gnomAD v2.1.1, gnomAD v3.1.2, Top Med Freeze 8) suggesting that it is not a common benign variant in the populations represented in those databases. The c.221A>G variant in MYH7 is located in exon 4 of this 40-exon gene, and is predicted to replace an evolutionarily conserved aspartic acid residue with glycine at position 74 [p.(Asp74Gly)] in the head/motor domain of the encoded protein [PMID: 34935411, 30924982]. In silico predictions are inconclusive for the variant’s damaging effect [REVEL = 0.382]; however, functional studies to support or refute these predictions have not been reported. Given the lack of compelling evidence for its pathogenicity, the c.221A>G p.(Asp74Gly) variant identified in the MYH7 gene is reported as a Variant of Uncertain Significance. -

Cardiomyopathy

Uncertain:1

Oct 02, 2023

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 aspartic acid with glycine at codon 74 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 MYH7-related disorders in the literature. This variant has not been identified 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:1

Aug 23, 2012

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

p.Asp74Gly (GAC>GGC):c.221 A>G in exon 4 of the MYH7 gene (NM_000257.2). The Asp74Gly variant in the MYH7 gene has not been reported as a disease-causing mutation or as a benign polymorphism to our knowledge. Asp74Gly results in a non-conservative amino acid substitution of a negatively charged Aspartic acid residue with a non-polar Glycine residue at a position that is conserved across species. However, in silico analysis predicts Asp74Gly is benign to the protein structure/function. Nevertheless, the NHLBI ESP Exome Variant Server reports Asp74Gly was not observed in approximately 6,000 samples from individuals of European and African American backgrounds, indicating it is not a common benign variant in these populations. With the clinical and molecular information available at this time, we cannot definitively determine if Asp74Gly is a disease-causing mutation or a rare benign variant. The variant is found in HCM panel(s). -

Hypertrophic cardiomyopathy

Uncertain:1

Jul 19, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 74 of the MYH7 protein (p.Asp74Gly). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with MYH7-related conditions. ClinVar contains an entry for this variant (Variation ID: 181298). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.20

CardioboostCm

Benign

0.055

BayesDel_addAF

Uncertain

0.052

BayesDel_noAF

Benign

-0.16

CADD

Uncertain

DANN

Uncertain

0.98

DEOGEN2

Pathogenic

0.81

Eigen

Benign

-0.38

Eigen_PC

Benign

-0.39

FATHMM_MKL

Benign

0.18

LIST_S2

Uncertain

0.93

M_CAP

Pathogenic

0.67

MetaRNN

Uncertain

0.44

MetaSVM

Uncertain

-0.12

MutationAssessor

Uncertain

2.8

PrimateAI

Benign

0.43

PROVEAN

Uncertain

-3.3

REVEL

Uncertain

0.38

Sift

Benign

0.034

Sift4G

Uncertain

0.035

Polyphen

0.0

Vest4

0.41

MutPred

0.59

Gain of catalytic residue at V71 (P = 0.0211);

MVP

0.81

MPC

1.3

ClinPred

0.23

GERP RS

3.6

Varity_R

0.55

gMVP

0.73

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