chr14-23424893-A-G

Variant names:

• chr14-23424893-A-G
• rs397516157
• NM_000257.4:c.2555T>C

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_000257.4(MYH7):​c.2555T>C​(p.Met852Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,146 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M852I) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 8.83
• Publications: 6 publications found

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 Gene-Disease associations (from GenCC):

• dilated cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• dilated cardiomyopathy 1S

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• hypertrophic cardiomyopathy 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• MYH7-related skeletal myopathy

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), ClinGen, Ambry Genetics
• myopathy, myosin storage, autosomal recessive

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• myopathy, myosin storage, autosomal dominant

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• congenital myopathy 7A, myosin storage, autosomal dominant

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Ebstein anomaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hyaline body myopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• left ventricular noncompaction

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• congenital heart disease

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 19 ACMG points.

• PM1: In a hotspot region, there are 13 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 19 uncertain 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 chr14-23424893-A-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 181375.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• 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 myopathy, myosin storage, autosomal recessive, MYH7-related skeletal myopathy, congenital myopathy 7A, myosin storage, autosomal dominant, Ebstein anomaly, hyaline body myopathy, left ventricular noncompaction, hypertrophic cardiomyopathy 1, dilated cardiomyopathy 1S, dilated cardiomyopathy, congenital heart disease, familial isolated dilated cardiomyopathy, myopathy, myosin storage, autosomal dominant, arrhythmogenic right ventricular cardiomyopathy, hypertrophic cardiomyopathy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.948
• PP5: Variant 14-23424893-A-G is Pathogenic according to our data. Variant chr14-23424893-A-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 42916.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH7	NM_000257.4	c.2555T>C	p.Met852Thr	missense_variant	Exon 22 of 40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.2555T>C	p.Met852Thr	missense_variant	Exon 21 of 39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.2555T>C	p.Met852Thr	missense_variant	Exon 22 of 40	1	NM_000257.4	ENSP00000347507.3
MYH7	ENST00000713768.1	c.2555T>C	p.Met852Thr	missense_variant	Exon 22 of 41			ENSP00000519070.1
MYH7	ENST00000713769.1	c.2555T>C	p.Met852Thr	missense_variant	Exon 21 of 39			ENSP00000519071.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152146 Hom.: 0 Cov.: 32

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 Cov.: 33

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152146 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74320

African (AFR) AF: 0.00 AC: 0 AN: 41424

American (AMR) AF: 0.00 AC: 0 AN: 15290

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5186

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68018

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.0000267 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Hypertrophic cardiomyopathy Pathogenic:2

Jan 31, 2019

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Met852Thr variant in MYH7 has been reported in 5 individuals with HCM (Richard 2003, Morita 2008, Marsiglia 2013, Walsh 2016, LMM unpublished data). This variant has also been identified in 1/15420 European chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org/; dbSNP rs397516157). Methionine (Met) at position 852 is highly conserved in mammals and across evolutionarily distant species and the change to threonine (Thr) was predicted to be pathogenic using a computational tool clinically validated by our laboratory. This tool's pathogenic prediction is estimated to be correct 94% of the time (Jordan 2011). Additionally, this variant lies in the head region of the protein. Missense variants in this region have been reported and statistically indicated to be more likely to cause disease (Walsh 2016). In summary, although additional studies are required to fully establish its clinical significance, the p.Met852Thr variant is likely pathogenic. ACMG/AMP Criteria applied: PM1; PM2; PP3; PS4_Supporting. -

Jan 11, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 852 of the MYH7 protein (p.Met852Thr). This variant is present in population databases (rs397516157, gnomAD no frequency). This missense change has been observed in individuals with hypertrophic cardiomyopathy and familial left ventricular hypertrophy (PMID: 12707239, 18403758, 24093860, 27247418). ClinVar contains an entry for this variant (Variation ID: 42916). 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 expected to disrupt MYH7 protein function with a positive predictive value of 95%. This variant is found within a region of MYH7 between codons 181 and 937 that contains the majority of the myosin head domain. Missense variants in this region have been shown to be significantly overrepresented in individuals with hypertrophic cardiomyopathy (PMID: 27532257). For these reasons, this variant has been classified as Pathogenic. -

Cardiovascular phenotype Pathogenic:2

Apr 11, 2024

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.M852T variant (also known as c.2555T>C), located in coding exon 20 of the MYH7 gene, results from a T to C substitution at nucleotide position 2555. The methionine at codon 852 is replaced by threonine, an amino acid with similar properties, and is located in the head domain. This alteration has been detected in multiple individuals with hypertrophic cardiomyopathy (HCM) and was reported to segregate with disease in one small family (Richard P et al. Circulation, 2003 May;107:2227-32; Morita H et al. N. Engl. J. Med., 2008 May;358:1899-908; Marsiglia JD et al. Am. Heart J., 2013 Oct;166:775-82; Walsh R et al. Genet. Med., 2017 02;19:192-203; external communication). 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 highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Jan 21, 2025

Molecular Diagnostic Laboratory for Inherited Cardiovascular Disease, Montreal Heart Institute

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM1;PM2;PM5;PP3;PS4_supp -

Hypertrophic cardiomyopathy 1 Pathogenic:2

-

Laboratory of Genetics and Molecular Cardiology, University of São Paulo

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 25, 2024

3billion

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.003%). Predicted Consequence/Location: The variant is located in a mutational hot spot and/or well-established functional domain in which established pathogenic variants have been reported (PMID: 29300372). In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.95 (>=0.6, sensitivity 0.68 and specificity 0.92); 3Cnet: 0.98 (>=0.6, sensitivity 0.72 and precision 0.9)]. Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000042916 /PMID: 12707239 /3billion dataset). Different missense changes at the same codon (p.Met852Arg, p.Met852Ile, p.Met852Lys) have been reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000181375, VCV000454357, VCV000567905). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.35
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.51
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.82	D
Eigen	Pathogenic	0.83
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.95	D
M_CAP	Pathogenic	0.95	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.8	H
PhyloP100		8.8
PrimateAI	Pathogenic	0.79	T
PROVEAN	Uncertain	-4.1	D
REVEL	Pathogenic	0.95
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.050	T
Polyphen		0.98	D
Vest4		0.95
MutPred		0.73		Gain of phosphorylation at M852 (P = 0.0213);
MVP		0.97
MPC		2.2
ClinPred		1.0	D
GERP RS		4.7
Varity_R		0.86
gMVP		0.99
Mutation Taster		=5/95	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs397516157; hg19: chr14-23894102;