chr14-23417562-C-G

Position:

• chr14-23417562-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_000257.4(MYH7):​c.4294G>C​(p.Val1432Leu) 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 benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency: Genomes: not found (cov: 33)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.07

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]

MHRT (HGNC:51291): (myosin heavy chain associated RNA transcript) This gene encodes a spliced long non-coding RNA that may act as a cardioprotective agent in the heart. Based on a study of a similar gene in mouse, the encoded transcript may regulate chromatin remodeling by acting as a decoy to the BRG1 chromatin repressor complex thus preventing it from binding to its genomic targets. Blocking the actions of BRG1 could be crucial in protecting the heart from pathological hypertrophy. [provided by RefSeq, Dec 2014]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), MYH7. . Gene score misZ: 3.9329 (greater than the threshold 3.09). Trascript score misZ: 6.7889 (greater than threshold 3.09). The gene has 341 curated pathogenic missense variants (we use a threshold of 10). The gene has 16 curated benign missense variants. GenCC has associacion of the gene with 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.29502386).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYH7	NM_000257.4	c.4294G>C	p.Val1432Leu	missense_variant	31/40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.4294G>C	p.Val1432Leu	missense_variant	30/39		NP_001393933.1
MHRT	NR_126491.1	n.843C>G		non_coding_transcript_exon_variant	6/6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.4294G>C	p.Val1432Leu	missense_variant	31/40	1	NM_000257.4	ENSP00000347507.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.25
CardioboostCm	Benign	0.017
BayesDel_addAF	Benign	-0.093	T
BayesDel_noAF	Benign	-0.37
CADD	Benign	22
DANN	Benign	0.95
DEOGEN2	Uncertain	0.45	T
Eigen	Benign	-0.50
Eigen_PC	Benign	-0.28
FATHMM_MKL	Benign	0.59	D
LIST_S2	Uncertain	0.87	D
M_CAP	Uncertain	0.27	D
MetaRNN	Benign	0.30	T
MetaSVM	Benign	-0.84	T
MutationAssessor	Benign	-0.49	N
PrimateAI	Uncertain	0.64	T
PROVEAN	Benign	0.22	N
REVEL	Benign	0.24
Sift	Benign	0.69	T
Sift4G	Benign	1.0	T
Polyphen		0.0010	B
Vest4		0.34
MutPred		0.54		Gain of catalytic residue at M1429 (P = 0.0868);
MVP		0.72
MPC		0.77
ClinPred		0.18	T
GERP RS		5.0
Varity_R		0.12
gMVP		0.96

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: rs144200285; hg19: chr14-23886771;