NM_000257.4:c.4238C>A

Variant names:

• chr14-23417618-G-T
• rs730880796
• NM_000257.4:c.4238C>A

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_000257.4(MYH7):​c.4238C>A​(p.Ser1413*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,598 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. S1413S) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay. The gene MYH7 is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MYH7 NM_000257.4 stop_gained
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.72
• Publications: 5 publications found

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

Specifications for MYH7 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000257.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYH7	NM_000257.4	MANE Select	c.4238C>A	p.Ser1413*	stop_gained	Exon 31 of 40	NP_000248.2	P12883
	MYH7	NM_001407004.1		c.4238C>A	p.Ser1413*	stop_gained	Exon 30 of 39	NP_001393933.1	P12883
	MHRT	NR_126491.1		n.*23G>T		downstream_gene	N/A

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MYH7	ENST00000355349.4	TSL:1 MANE Select	c.4238C>A	p.Ser1413*	stop_gained	Exon 31 of 40	ENSP00000347507.3	P12883
	MYH7	ENST00000858540.1		c.4238C>A	p.Ser1413*	stop_gained	Exon 31 of 40	ENSP00000528599.1
	MYH7	ENST00000965955.1		c.4238C>A	p.Ser1413*	stop_gained	Exon 31 of 40	ENSP00000636014.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251478 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460598 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 726606

African (AFR) AF: 0.00 AC: 0 AN: 33436

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86194

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4700

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112006

Other (OTH) AF: 0.00 AC: 0 AN: 60284

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	1	-	Cardiomyopathy (1)
-	1	-	Hypertrophic cardiomyopathy (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	43
DANN	Uncertain	1.0
Eigen	Pathogenic	0.80
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		9.7
Vest4		0.91
GERP RS		5.0
Mutation Taster		=8/192	disease causing (fs/PTC)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs730880796; hg19: chr14-23886827;