NM_000257.4:c.637A>G

Variant names:

• chr14-23431763-T-C
• rs1555338682
• NM_000257.4:c.637A>G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_000257.4(MYH7):​c.637A>G​(p.Lys213Glu) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: MYH7 NM_000257.4 missense, splice_region
• Scores: Splicing: ADA: 0.01898
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.46

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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• 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 hyaline body myopathy, MYH7-related skeletal myopathy, dilated cardiomyopathy 1S, congenital myopathy 7A, myosin storage, autosomal dominant, dilated cardiomyopathy, left ventricular noncompaction, myopathy, myosin storage, autosomal dominant, hypertrophic cardiomyopathy, congenital heart disease, Ebstein anomaly, arrhythmogenic right ventricular cardiomyopathy, myopathy, myosin storage, autosomal recessive, hypertrophic cardiomyopathy 1, familial isolated dilated cardiomyopathy.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MYH7	NM_000257.4	c.637A>G	p.Lys213Glu	missense_variant, splice_region_variant	Exon 7 of 40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.637A>G	p.Lys213Glu	missense_variant, splice_region_variant	Exon 6 of 39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.637A>G	p.Lys213Glu	missense_variant, splice_region_variant	Exon 7 of 40	1	NM_000257.4	ENSP00000347507.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hypertrophic cardiomyopathy Uncertain:1

Jul 31, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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). 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. A computational algorithm designed to assess the pathogenicity of variants in MYH7 with regard to hypertrophic cardiomyopathy predicted this sequence change to be tolerated. The algorithm has a sensitivity of 94% and a specificity of 89% (PMID: 21310275). This sequence change replaces lysine with glutamic acid at codon 213 of the MYH7 protein (p.Lys213Glu). The lysine residue is highly conserved and there is a small physicochemical difference between lysine and glutamic acid. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with MYH7-related disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.48
CardioboostCm	Uncertain	0.47
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	-0.040
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.77	D
Eigen	Benign	-0.20
Eigen_PC	Benign	-0.16
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.83	T
M_CAP	Pathogenic	0.91	D
MetaRNN	Uncertain	0.66	D
MetaSVM	Uncertain	-0.011	T
MutationAssessor	Benign	1.4	L
PrimateAI	Uncertain	0.61	T
PROVEAN	Benign	-1.9	N
REVEL	Uncertain	0.61
Sift	Uncertain	0.0020	D
Sift4G	Benign	0.28	T
Polyphen		0.020	B
Vest4		0.51
MutPred		0.45		Loss of ubiquitination at K213 (P = 0.0034);
MVP		0.94
MPC		1.9
ClinPred		0.79	D
GERP RS		3.1
Varity_R		0.69
gMVP		0.86

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.019
dbscSNV1_RF	Benign	0.15
SpliceAI score (max)		0.010		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: rs1555338682; hg19: chr14-23900972;