rs397516128

Variant names:

• chr14-23426057-A-G
• rs397516128
• NM_000257.4:c.2069T>C

Variant summary

Our verdict is Uncertain significance. The variant received 6 ACMG points: 6P and 0B. PS4_Supporting PM2 PM1 PP3

This summary comes from the ClinGen Evidence Repository: The c.2069T>C (p.Met690Thr) variant in MYH7 has been reported in at least 3 individuals with HCM (PS4_Supporting; Coppini 2014 PMID:25524337; Homberger 2016 PMID:27247418; Weissler-Snir 2017 PMID:28193612; Walsh 2017 PMID:27532257; CHEO pers. comm.; LMM pers. comm.; OMGL pers. comm.). This variant was absent from large population studies (PM2; http://gnomad.broadinstitute.org, v2.1.1). This variant lies in the head region of the protein (aa 181-937) and missense variants in this region are statistically more likely to be associated with HCM (PM1; Walsh 2017 PMID:27532257). Computational prediction tools and conservation analysis suggest that this variant may impact the protein (PP3). Based on criteria selected, this variant would be classified as likely pathogenic; however the expert panel deemed the bulk of available evidence as being derived from predictive models. Therefore, in the absence of additional case or segregation data, this variant is classified as uncertain significance for hypertrophic cardiomyopathy in an autosomal dominant manner. ACMG/AMP Criteria applied: PS4_Supporting; PM2; PM1; PP3. LINK:https://erepo.genome.network/evrepo/ui/classification/CA011635/MONDO:0005045/002

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Uncertain significance reviewed by expert panel P:1 U:3
• Conservation: PhyloP100: 9.02
• Publications: 3 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: Uncertain_significance. The variant received 6 ACMG points.

• PS4: For more information check the summary or visit ClinGen Evidence Repository.
• PM1: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH7	NM_000257.4	c.2069T>C	p.Met690Thr	missense_variant	Exon 19 of 40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.2069T>C	p.Met690Thr	missense_variant	Exon 18 of 39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.2069T>C	p.Met690Thr	missense_variant	Exon 19 of 40	1	NM_000257.4	ENSP00000347507.3
MYH7	ENST00000713768.1	c.2069T>C	p.Met690Thr	missense_variant	Exon 19 of 41			ENSP00000519070.1
MYH7	ENST00000713769.1	c.2069T>C	p.Met690Thr	missense_variant	Exon 18 of 39			ENSP00000519071.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:3

Revision: reviewed by expert panel

Submissions by phenotype

Hypertrophic cardiomyopathy Pathogenic:1 Uncertain:2

Feb 06, 2023

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Met690Thr variant in MYH7 has been reported in at least 3 individuals with hypertrophic cardiomyopathy (HCM) and segregated with disease in 1 affected relative from 1 family (Coppini 2014 PMID:25524337; Homburger 2016 PMID:27247418; Walsh 2017 PMID:27532257; Marschall 2019 PMID:31737537, LMM data). It was absent from large population studies. Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. This variant lies in the head region of the protein and missense variants in this region are statistically more likely to be disease-associated (Walsh 2017 PMID 27532257). Moreover, this variant was classified as Uncertain Significance on September 22, 2021 by the ClinGen-approved Cardiomyopathy expert panel (Variation ID 42876). In summary, while there is some suspicion for a pathogenic role, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: PM1, PS4_Supporting, PM2_Supporting, PP3. -

Sep 22, 2021

ClinGen Cardiomyopathy Variant Curation Expert Panel

Significance: Uncertain significance

Review Status: reviewed by expert panel

Collection Method: curation

The c.2069T>C (p.Met690Thr) variant in MYH7 has been reported in at least 3 individuals with HCM (PS4_Supporting; Coppini 2014 PMID:25524337; Homberger 2016 PMID:27247418; Weissler-Snir 2017 PMID:28193612; Walsh 2017 PMID:27532257; CHEO pers. comm.; LMM pers. comm.; OMGL pers. comm.). This variant was absent from large population studies (PM2; http://gnomad.broadinstitute.org, v2.1.1). This variant lies in the head region of the protein (aa 181-937) and missense variants in this region are statistically more likely to be associated with HCM (PM1; Walsh 2017 PMID:27532257). Computational prediction tools and conservation analysis suggest that this variant may impact the protein (PP3). Based on criteria selected, this variant would be classified as likely pathogenic; however the expert panel deemed the bulk of available evidence as being derived from predictive models. Therefore, in the absence of additional case or segregation data, this variant is classified as uncertain significance for hypertrophic cardiomyopathy in an autosomal dominant manner. ACMG/AMP Criteria applied: PS4_Supporting; PM2; PM1; PP3. -

Nov 03, 2023

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 690 of the MYH7 protein (p.Met690Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with hypertrophic cardiomyopathy (PMID: 25524337, 27247418, 27532257). ClinVar contains an entry for this variant (Variation ID: 42876). 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 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. -

Cardiomyopathy Uncertain:1

Oct 17, 2016

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
CardioboostCm	Uncertain	0.79
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.25
CADD	Uncertain	26
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.87	D
Eigen	Uncertain	0.58
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.94	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Pathogenic	0.87	D
MutationAssessor	Benign	0.93	L
PhyloP100		9.0
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-3.5	D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0020	D
Polyphen		0.78	P
Vest4		0.83
MutPred		0.60		Gain of catalytic residue at L693 (P = 0.004);
MVP		1.0
MPC		2.1
ClinPred		0.99	D
GERP RS		4.8
Varity_R		0.80
gMVP		0.98
Mutation Taster		=0/100	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: rs397516128; hg19: chr14-23895266;