rs397516272

Positions:

• chr14-23430924-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2_Supporting PM1 PP3 PS4_Supporting

This summary comes from the ClinGen Evidence Repository: The NM_000257.4 (MYH7): c.872C>T (p.Ser291Phe) variant has been reported in at least 4 individuals with HCM (PS4_Supporting; Lakdawala 2011 PMID:21943931; Marsiglia 2013 PMID:24093860; Homburger 2016 PMID:27247418; Walsh 2017 PMID:27532257; LMM pers. comm.); however, one of these individuals had early-onset HCM (<25 yo) and also carried a second MYH7 variant that is classified as likely pathogenic by this expert panel (p.Lys847del, LMM pers. comm.). This variant was absent from large population studies (PM2_Supporting; http://gnomad.broadinstitute.org, v2.1.1). Following the ClinGen Sequence Variant Interpretation (SVI) working group recommendation for weight adjustment of the PM2 criterion due to concerns that rarity in the general population may not meet the relative odds of pathogenicity for moderate evidence, the PM2 criterion was downgraded to PM2_Supporting. 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 disease-associated (PM1; Walsh 2017 PMID:27532257). Computational prediction tools and conservation analysis suggest that this variant may impact the protein (PP3). In summary, due to insufficient evidence, this variant meets criteria to be classified as uncertain significance for hypertrophic cardiomyopathy in an autosomal dominant manner. MYH7-specific ACMG/AMP criteria applied (Kelly 2018 PMID:29300372): PS4_Supporting; PM2_Supporting; PM1; PP3. LINK:https://erepo.genome.network/evrepo/ui/classification/CA016918/MONDO:0005045/002

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:3
• Conservation: PhyloP100: 7.72

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 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/exons	MANE	Protein	UniProt
MYH7	NM_000257.4	c.872C>T	p.Ser291Phe	missense_variant	10/40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.872C>T	p.Ser291Phe	missense_variant	9/39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.872C>T	p.Ser291Phe	missense_variant	10/40	1	NM_000257.4	ENSP00000347507.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461510 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727108

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hypertrophic cardiomyopathy 1 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Laboratory of Genetics and Molecular Cardiology, University of São Paulo

-

- -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Jul 10, 2018

Variant classified as Uncertain Significance - Favor Pathogenic. The p.Ser291Phe variant in MYH7 has been identified by our laboratory in 2 individuals with HCM . One of these individuals had a second disease-causing variant in MYH7 and pres ented at an earlier age. This variant was absent from large population studies. Computational prediction tools and conservation analysis suggest that the p.Ser2 91Phe variant may impact the protein, though this information is not predictive enough to determine pathogenicity. Additionally, this variant lies in the head r egion of the protein. Missense variants in this region have been reported and st atistically indicated to be more likely to cause disease (Walsh 2016). In summar y, while there is some suspicion for a pathogenic role, the clinical significanc e of the p.Ser291Phe variant is uncertain. ACMG/AMP Criteria applied: PM1; PM2; PP3. -

Hypertrophic cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 17, 2020

This variant is not present in population databases (ExAC no frequency). This sequence change replaces serine with phenylalanine at codon 291 of the MYH7 protein (p.Ser291Phe). The serine residue is highly conserved and there is a large physicochemical difference between serine and phenylalanine. This variant has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 21943931, 27247418, 24093860). ClinVar contains an entry for this variant (Variation ID: 43110). 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. 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). 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 C15"). -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 04, 2021

The p.S291F variant (also known as c.872C>T), located in coding exon 8 of the MYH7 gene, results from a C to T substitution at nucleotide position 872. The serine at codon 291 is replaced by phenylalanine, an amino acid with highly dissimilar properties. 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 variant has been reported in hypertrophic cardiomyopathy (HCM) clinical and genetic testing cohorts; however, limited details were provided (Lakdawala NK et al. Am J Cardiol, 2011 Dec;108:1606-13; Marsiglia JD et al. Am Heart J, 2013 Oct;166:775-82; 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). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.91	D
Eigen	Pathogenic	0.78
Eigen_PC	Uncertain	0.64
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.90	D
M_CAP	Pathogenic	0.98	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	2.9	M
PrimateAI	Pathogenic	0.80	T
PROVEAN	Uncertain	-4.3	D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.97
MutPred		0.73		Gain of catalytic residue at L290 (P = 0.0014);
MVP		0.99
MPC		2.2
ClinPred		1.0	D
GERP RS		3.6
Varity_R		0.90
gMVP		0.95

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

Other links and lift over

dbSNP: rs397516272; hg19: chr14-23900133;