NM_002471.4:c.679G>A

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BS2

The NM_002471.4(MYH6):c.679G>A(p.Ala227Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000186 in 1,614,220 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. A227V) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000072 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000013 ( 0 hom. )

Consequence

MYH6
NM_002471.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 0.252

Publications

2 publications found

Variant links:

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 Gene-Disease associations (from GenCC):

hypertrophic cardiomyopathy 14
Inheritance: AD Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), PanelApp Australia, Laboratory for Molecular Medicine
Keppen-Lubinsky syndrome
Inheritance: AD Classification: MODERATE Submitted by: Illumina
familial isolated dilated cardiomyopathy
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
atrial septal defect 3
Inheritance: AD Classification: LIMITED Submitted by: G2P
dilated cardiomyopathy
Inheritance: AD Classification: LIMITED Submitted by: ClinGen
hypertrophic cardiomyopathy
Inheritance: AD Classification: LIMITED Submitted by: ClinGen

MYH6 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BS2

High AC in GnomAd4 at 11 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH6	NM_002471.4 link	c.679G>A	p.Ala227Thr	missense_variant	Exon 8 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.679G>A	p.Ala227Thr	missense_variant	Exon 8 of 39	5	NM_002471.4	ENSP00000386041.3		P13533
MYH6	ENST00000557461.2 link	n.746G>A		non_coding_transcript_exon_variant	Exon 8 of 14	5

Frequencies

GnomAD3 genomes

AF:

0.0000723

AC:

AN:

152218

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000523

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:

0.00

Gnomad OTH

AF:

0.00143

GnomAD2 exomes

AF:

0.0000278

AC:

AN:

251486

AF XY:

0.0000294

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000578

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000130

AC:

AN:

1461884

Hom.:

Cov.:

AF XY:

0.0000151

AC XY:

AN XY:

727244

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.0000671

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39700

South Asian (SAS)

AF:

0.000104

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1112004

Other (OTH)

AF:

0.0000662

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.478

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000722

AC:

AN:

152336

Hom.:

Cov.:

AF XY:

0.0000671

AC XY:

AN XY:

74480

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41586

American (AMR)

AF:

0.000523

AC:

AN:

15306

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5178

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10628

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68020

Other (OTH)

AF:

0.00142

AC:

AN:

2116

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.466

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000205

Hom.:

Bravo

AF:

0.000208

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ExAC

AF:

0.0000247

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jun 14, 2013

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The Ala227Thr variant in MYH6 has not been reported in individuals with cardiomy opathy, but has been identified in 1.8% (2/110) of Puerto Rican chromosomes by t he 1000 Genomes Project (dbSNP rs201828188). Computational analyses (biochemical amino acid properties, conservation, AlignGVGD, PolyPhen2, and SIFT) do not pro vide strong support for or against an impact to the protein. The presence of thi s variant in the general population raises the possibility that it may be benign but this additional information is needed to establish this with confidence -

Hypertrophic cardiomyopathy 14

Uncertain:1

Jul 12, 2024

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 threonine, which is neutral and polar, at codon 227 of the MYH6 protein (p.Ala227Thr). This variant is present in population databases (rs201828188, gnomAD 0.01%). This missense change has been observed in individual(s) with dilated cardiomyopathy (PMID: 32746448). ClinVar contains an entry for this variant (Variation ID: 164254). 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 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. -

not provided

Uncertain:1

Aug 30, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis indicates that this missense variant does not alter protein structure/function; This variant is associated with the following publications: (PMID: 32746448) -

Cardiovascular phenotype

Uncertain:1

Oct 09, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.A227T variant (also known as c.679G>A), located in coding exon 6 of the MYH6 gene, results from a G to A substitution at nucleotide position 679. The alanine at codon 227 is replaced by threonine, an amino acid with similar properties. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.69

BayesDel_addAF

Benign

-0.16

BayesDel_noAF

Benign

-0.24

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.77

D;D

Eigen

Uncertain

0.33

Eigen_PC

Benign

0.16

FATHMM_MKL

Benign

0.42

LIST_S2

Benign

0.57

T;.

M_CAP

Uncertain

0.14

MetaRNN

Uncertain

0.63

D;D

MetaSVM

Uncertain

0.0081

MutationAssessor

Uncertain

2.6

M;M

PhyloP100

0.25

PrimateAI

Uncertain

0.73

PROVEAN

Benign

-1.7

N;N

REVEL

Uncertain

0.36

Sift

Uncertain

0.0080

D;D

Sift4G

Uncertain

0.015

D;D

Polyphen

1.0

D;D

Vest4

0.72

MVP

0.74

MPC

1.1

ClinPred

0.31

GERP RS

3.4

Varity_R

0.34

gMVP

0.77

Mutation Taster

=44/56

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over