Genetic Variant MYH6:p.Ala1443Asp (chr14-23388186-G-T) – ACMG Classification: Likely_benign (-4 pts)

Genes affected

MYH6 (HGNC:7576): (myosin heavy chain 6) Cardiac muscle myosin is a hexamer consisting of two heavy chain subunits, two light chain subunits, and two regulatory subunits. This gene encodes the alpha heavy chain subunit of cardiac myosin. The gene is located approximately 4kb downstream of the gene encoding the beta heavy chain subunit of cardiac myosin. Mutations in this gene cause familial hypertrophic cardiomyopathy and atrial septal defect 3. [provided by RefSeq, Feb 2017]

MYH6 links:

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

BS2

High AC in GnomAd4 at 26 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH6	NM_002471.4 link	c.4328C>A	p.Ala1443Asp	missense_variant	Exon 30 of 39	ENST00000405093.9	NP_002462.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYH6	ENST00000405093.9 link	c.4328C>A	p.Ala1443Asp	missense_variant	Exon 30 of 39	5	NM_002471.4	ENSP00000386041.3		P13533

Frequencies

GnomAD3 genomes

AF:

0.000171

AC:

AN:

152210

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000482

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000131

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:

0.000323

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000835

AC:

AN:

251422

Hom.:

AF XY:

0.000103

AC XY:

AN XY:

135888

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

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:

0.000176

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.000206

AC:

301

AN:

1459992

Hom.:

Cov.:

AF XY:

0.000191

AC XY:

139

AN XY:

726306

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000447

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:

0.000263

Gnomad4 OTH exome

AF:

0.0000996

GnomAD4 genome

AF:

0.000171

AC:

AN:

152210

Hom.:

Cov.:

AF XY:

0.000134

AC XY:

AN XY:

74352

show subpopulations

Gnomad4 AFR

AF:

0.0000482

Gnomad4 AMR

AF:

0.000131

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000323

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000128

Hom.:

Bravo

AF:

0.000132

ExAC

AF:

0.0000659

AC:

EpiCase

AF:

0.000164

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:16

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:6

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Apr 07, 2022

Revvity Omics, Revvity

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Clinical Genetics, Academic Medical Center

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Jan 25, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Identified in individuals with various forms of cardiac disease, including congenital heart defects, atrial fibrillation, and cardiomyopathies (Granados-Riveron et al., 2010; Granados-Riveron et al., 2012; Gonzalez-Garay et al., 2013; Tomita-Mitchell et al., 2016; Dal Ferro et al., 2017; Gigli et al., 2019; Marschall et al., 2019; Robyns et al., 2020; Verdonschot et al., 2020; Bowling et al., 2022; Zhu et al., 2022); 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: 28416588, 20656787, 27789736, 29875424, 31514951, 32880476, 35456442, 31513939, 31737537, 22011241, 34930662, 24082139) -

Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

not specified

Uncertain:2

Nov 01, 2013

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The Ala1443Asp variant in MYH6 has been reported in 1 individual with congenital heart disease (ASD) and was absent from at least 960 control chromosomes (Grana dos-Riveron 2010, Granados-Riveron 2012). It was also absent from large populati on studies. Computational analyses (biochemical amino acid properties, conservat ion, AlignGVGD, PolyPhen2, and SIFT) suggest that this variant may impact the pr otein, though this information is not predictive enough to determine pathogenici ty. In summary, additional information is needed to fully assess the clinical si gnificance of this variant. -

Jan 30, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: MYH6 c.4328C>A (p.Ala1443Asp) results in a non-conservative amino acid change located in the Myosin tail domain (IPR002928) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8.4e-05 in 251422 control chromosomes (gnomAD). The observed variant frequency is approximately 3 fold of the estimated maximal expected allele frequency for a pathogenic variant in MYH6 causing Cardiomyopathy phenotype (2.5e-05), strongly suggesting that the variant is benign. c.4328C>A has been reported in the literature in individuals affected or suspected with Cardiomyopathy (examples: Gonzalez_2013, Dal ferro_2017, Gigli_2019, Mazzarotto_2019, Marschall_2019, Verdonschot_2020), Congenital heart defects (Granados-Riveron_2010), atrial septal defects (Bowling_2022) and Hypoplastic left heart syndrome (Tomita-Mitchell_2016, Najib_ 2023). These report(s) do not provide unequivocal conclusions about association of the variant with Cardiomyopathy. The following publications have been ascertained in the context of this evaluation (PMID: 34930662, 28416588, 31514951, 24082139, 22011241, 31737537, 29875424, 36890431, 31513939, 27789736, 32880476, 35456442). ClinVar contains an entry for this variant (Variation ID: 164221). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Atrial septal defect 3

Uncertain:2

May 06, 2021

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3B. Following criteria are met: 0105 - The mechanism of disease for this gene is not clearly established. (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from alanine to aspartic acid. (I) 0251 - This variant is heterozygous. (I) 0302 - Variant is present in gnomAD (v2, v3) <0.001 for a dominant condition (26 heterozygotes, 0 homozygotes). (SP) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0600 - Variant is located in the annotated myosin tail domain (NCBI). (I) 0705 - No comparable missense variants have previous evidence for pathogenicity. (I) 0809 - Previous evidence of pathogenicity for this variant is inconclusive. This variant has been reported many times as a VUS within European cohorts (ClinVar, LOVD, cardiodb, PMID: 30847666, PMID: 29875424). (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Jul 12, 2018

HudsonAlpha Institute for Biotechnology, HudsonAlpha Institute for Biotechnology

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: research

ACMG codes: PP3 -

Hypertrophic cardiomyopathy 14

Uncertain:1

Jan 26, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 1443 of the MYH6 protein (p.Ala1443Asp). This variant is present in population databases (rs727503234, gnomAD 0.02%). This missense change has been observed in individual(s) with clinical features of MYH6-related conditions (PMID: 20656787, 24082139, 27789736, 28416588, 29875424, 31513939, 31737537, 32880476, 36890431). ClinVar contains an entry for this variant (Variation ID: 164221). 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) indicates that this missense variant is not expected to disrupt MYH6 protein function with a negative predictive value of 80%. 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. -

Dilated cardiomyopathy 1EE;C2750467:Hypertrophic cardiomyopathy 14;C3279790:Atrial septal defect 3;C3279791:Sick sinus syndrome 3, susceptibility to;C3495498:Hypertrophic cardiomyopathy 1

Uncertain:1

Sep 09, 2021

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Primary dilated cardiomyopathy

Uncertain:1

Sep 29, 2014

Blueprint Genetics

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Hypertrophic cardiomyopathy

Uncertain:1

Oct 31, 2018

Center for Human Genetics, University of Leuven

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Primary familial hypertrophic cardiomyopathy

Uncertain:1

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiovascular phenotype

Uncertain:1

Jul 07, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.A1443D variant (also known as c.4328C>A), located in coding exon 28 of the MYH6 gene, results from a C to A substitution at nucleotide position 4328. The alanine at codon 1443 is replaced by aspartic acid, an amino acid with dissimilar properties. This alteration has been reported in various cohorts, including those with hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), congenital heart defects (including a hypoplastic left heart syndrome (HLHS) cohort), as well as in a cohort of volunteers who underwent exome sequencing; however, clinical details were limited (Lopes LR et al. Heart, 2015 Feb;101:294-301; Dal Ferro M et al. Heart, 2017 11;103:1704-1710; Tomita-Mitchell A et al. Physiol. Genomics, 2016 12;48:912-921; Granados-Riveron JT et al. Congenit Heart Dis Oct;7:151-9; Gonzalez-Garay ML et al. Proc. Natl. Acad. Sci. U.S.A., 2013 Oct;110:16957-62; Mazzarotto F et al. Genet. Med., 2019 02;21:284-292; van Lint FHM et al. Neth Heart J, 2019 Jun;27:304-309). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious 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

Pathogenic

0.87

BayesDel_addAF

Uncertain

0.12

BayesDel_noAF

Pathogenic

0.21

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.68

D;D

Eigen

Pathogenic

0.68

Eigen_PC

Uncertain

0.63

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.94

D;.

M_CAP

Uncertain

0.20

MetaRNN

Uncertain

0.55

D;D

MetaSVM

Uncertain

0.59

MutationAssessor

Uncertain

2.5

M;M

PrimateAI

Uncertain

0.75

PROVEAN

Uncertain

-3.3

D;D

REVEL

Pathogenic

0.83

Sift

Uncertain

0.0040

D;D

Sift4G

Benign

0.29

T;T

Polyphen

0.94

P;P

Vest4

0.53

MVP

0.97

MPC

1.0

ClinPred

0.58

GERP RS

4.6

Varity_R

0.66

gMVP

0.72

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.

chr14-23388186-G-T

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

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