14-23425783-C-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5

The NM_000257.4(MYH7):c.2198G>A(p.Gly733Glu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G733V) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 4.78

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 Pathogenic. Variant got 12 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 10 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 chr14-23425783-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 181177.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant where missense usually causes diseases, MYH7
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.951
• PP5: Variant 14-23425783-C-T is Pathogenic according to our data. Variant chr14-23425783-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 177628.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=1}. Variant chr14-23425783-C-T is described in Lovd as [Pathogenic]. Variant chr14-23425783-C-T is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYH7	NM_000257.4	c.2198G>A	p.Gly733Glu	missense_variant	20/40	ENST00000355349.4
MYH7	NM_001407004.1	c.2198G>A	p.Gly733Glu	missense_variant	19/39

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYH7	ENST00000355349.4	c.2198G>A	p.Gly733Glu	missense_variant	20/40	1	NM_000257.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hypertrophic cardiomyopathy Pathogenic:1 Uncertain:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	May 21, 2019	The p.Gly733Glu variant in MYH7 has been reported in at least 5 individuals with HCM and segregated with disease in 5 affected relatives (Richard 2003, Maron 2011, Fujino 2013, LMM data). This variant was absent from large population studies. Computational prediction tools and conservation analyses do not provide strong support for or against an impact to the protein. Of note, 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). Two other variants at this position (p.Gly733Val and p.Gly733Arg) have also been reported in affected individuals. In summary, although additional studies are required to fully establish its clinical significance, the Gly733Glu variant is likely pathogenic. PM1, PM2, PP1_Moderate, PS4_Supporting. -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Apr 05, 2023	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. 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. ClinVar contains an entry for this variant (Variation ID: 177628). This missense change has been observed in individual(s) with hypertrophic cardiomyopathy (PMID: 12707239, 20975235, 21185001, 25611685). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 733 of the MYH7 protein (p.Gly733Glu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.91
CardioboostCm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
Cadd	Pathogenic	28
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.88	D
Eigen	Pathogenic	0.72
Eigen_PC	Pathogenic	0.68
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.97	D
M_CAP	Pathogenic	0.81	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Pathogenic	0.95	D
MutationAssessor	Uncertain	2.1	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.84	D
PROVEAN	Uncertain	-4.4	D
REVEL	Pathogenic	0.88
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.034	D
Polyphen		1.0	D
Vest4		0.91
MutPred		0.73		Gain of catalytic residue at I736 (P = 0.0032);
MVP		0.99
MPC		2.4
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.77
gMVP		0.97

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: rs727504241; hg19: chr14-23894992; COSMIC: COSV100806141;