rs1555338124

chr14-23427651-A-C

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PP2 PP3_Moderate

The NM_000257.4(MYH7):c.1822T>G(p.Leu608Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L608S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.737

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 Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a hotspot region, there are 8 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_000257.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, MYH7
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.892

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYH7	NM_000257.4	c.1822T>G	p.Leu608Val	missense_variant	16/40	ENST00000355349.4
MYH7	NM_001407004.1	c.1822T>G	p.Leu608Val	missense_variant	15/39

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYH7	ENST00000355349.4	c.1822T>G	p.Leu608Val	missense_variant	16/40	1	NM_000257.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

May 18, 2016

Variant classified as Uncertain Significance - Favor Pathogenic. The p.Leu608Val variant in MYH7 has not been previously reported in individuals with cardiomyop athy or in large population studies. This variant 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). In summary, while there is some suspicion for a pathogenic role, the clinical si gnificance of the p.Leu608Val variant is uncertain. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
CardioboostCm	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.33	D
BayesDel_noAF	Pathogenic	0.23
Cadd	Benign	20
Dann	Benign	0.97
DEOGEN2	Uncertain	0.77	D
Eigen	Benign	-0.66
Eigen_PC	Benign	-0.89
FATHMM_MKL	Benign	0.40	N
LIST_S2	Uncertain	0.87	D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.89	D
MetaSVM	Uncertain	0.27	D
MutationAssessor	Benign	1.8	L
MutationTaster	Benign	0.88	D
PrimateAI	Uncertain	0.65	T
PROVEAN	Benign	-1.7	N
REVEL	Uncertain	0.58
Sift	Benign	0.15	T
Sift4G	Benign	0.20	T
Polyphen		0.85	P
Vest4		0.81
MutPred		0.64		Gain of catalytic residue at Q610 (P = 2e-04);
MVP		0.77
MPC		1.3
ClinPred		0.30	T
GERP RS		-5.5
Varity_R		0.46
gMVP		0.84

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: rs1555338124; hg19: chr14-23896860; COSMIC: COSV105912863;