rs786204364

Positions:

chr14-23432479-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1PP2PP3_Strong

The NM_000257.4(MYH7):c.530C>T(p.Thr177Ile) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000041 in 1,461,872 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. 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. T177S) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

MYH7
NM_000257.4 missense, splice_region

Scores

Splicing: ADA: 0.5227

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:7

Conservation

PhyloP100: 7.89

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 7 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_000257.4

PP2

Missense variant in gene, where missense usually causes diseases (based on misZ statistic), MYH7. . Gene score misZ 3.9329 (greater than the threshold 3.09). Trascript score misZ 6.7889 (greater than threshold 3.09). GenCC has associacion of gene with 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, 0.953

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYH7	NM_000257.4 linkuse as main transcript	c.530C>T	p.Thr177Ile	missense_variant, splice_region_variant	6/40	ENST00000355349.4
MYH7	NM_001407004.1 linkuse as main transcript	c.530C>T	p.Thr177Ile	missense_variant, splice_region_variant	5/39

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYH7	ENST00000355349.4 linkuse as main transcript	c.530C>T	p.Thr177Ile	missense_variant, splice_region_variant	6/40	1	NM_000257.4	P1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000119

AC:

AN:

251482

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135914

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:

0.0000653

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000410

AC:

AN:

1461872

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

727240

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:

0.0000348

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000270

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Alfa

AF:

0.0000688

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Cardiomyopathy

Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Aug 15, 2023	This missense variant replaces threonine with isoleucine at codon 177 of the MYH7 protein. Computational prediction suggests that this variant may have a 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 individuals affected with hypertrophic cardiomyopathy (PMID: 20624503, 20800588, 23140321, 27247418). One of these individuals also carried a pathogenic variant in the TNNT2 gene (PMID: 20624503). This variant has been identified in 3/251482 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Aug 04, 2023	This missense variant replaces threonine with isoleucine at codon 177 of the MYH7 protein. Computational prediction suggests that this variant may have a 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 individuals affected with hypertrophic cardiomyopathy (PMID: 20624503, 20800588, 23140321, 27247418). One of these individuals also carried a pathogenic variant in the TNNT2 gene (PMID: 20624503). This variant has been identified in 3/251482 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario	Feb 16, 2022	- -

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Mar 01, 2017

Variant identified in a genome or exome case(s) and assessed due to predicted null impact of the variant or pathogenic assertions in the literature or databases. Disclaimer: This variant has not undergone full assessment. The following are preliminary notes: 3 papers HGMD, variant found in 1 patient with a TNNT2 variant, 1 variant in 1 HCM cohort, -

Hypertrophic cardiomyopathy

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 07, 2022

This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 177 of the MYH7 protein (p.Thr177Ile). This variant is present in population databases (rs752930302, gnomAD 0.006%). This missense change has been observed in individual(s) with clinical features of hypertrophic cardiomyopathy (PMID: 27247418). ClinVar contains an entry for this variant (Variation ID: 188596). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 15, 2020

The p.T177I variant (also known as c.530C>T), located in coding exon 4 of the MYH7 gene, results from a C to T substitution at nucleotide position 530. The amino acid change results in threonine to isoleucine at codon 177, an amino acid with similar properties. This variant has been detected in hypertrophic cardiomyopathy (HCM) cohorts; however, in one case, it co-occurred with a mutation in the TNNT2 gene (Millat G et al. Eur J Med Genet. 2010 Jul;53:261-7; Teirlinck CH et al. BMC Med. Genet., 2012 Nov;13:105; Homburger JR et al. Proc. Natl. Acad. Sci. U.S.A., 2016 06;113:6701-6). A different variant affecting this codon (p.T177S, c.530C>G) has been detected in an HCM cohort; however, it co-occurred with another variant in a cardiac-related gene (Mademont-Soler I et al. PLoS ONE, 2017 Aug;12:e0181465). This amino acid position is highly 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. -

Hypertrophic cardiomyopathy 1

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

MGZ Medical Genetics Center

Feb 14, 2022

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

1.0

CardioboostCm

Pathogenic

1.0

BayesDel_addAF

Pathogenic

0.34

BayesDel_noAF

Pathogenic

0.43

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.95

Eigen

Pathogenic

0.93

Eigen_PC

Pathogenic

0.76

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.90

M_CAP

Pathogenic

0.97

MetaRNN

Pathogenic

0.95

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

4.0

MutationTaster

Benign

1.0

PrimateAI

Pathogenic

0.92

PROVEAN

Pathogenic

-4.5

REVEL

Pathogenic

0.91

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.92

MutPred

0.65

Gain of catalytic residue at S180 (P = 0);

MVP

0.95

MPC

2.2

ClinPred

1.0

GERP RS

3.8

Varity_R

0.92

gMVP

0.98

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Benign

0.52

dbscSNV1_RF

Benign

0.65

SpliceAI score (max)

0.010

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