14-23433722-G-C

Position:

• chr14-23433722-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PM5 PP2 PP3

The ENST00000355349.4(MYH7):​c.11C>G​(p.Ser4Trp) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,622 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S4L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MYH7 ENST00000355349.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.92

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 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr14-23433722-G-A is described in Lovd as [Pathogenic].
• 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). GenCC has associacion of 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.762

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYH7	NM_000257.4	c.11C>G	p.Ser4Trp	missense_variant	3/40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.11C>G	p.Ser4Trp	missense_variant	2/39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.11C>G	p.Ser4Trp	missense_variant	3/40	1	NM_000257.4	ENSP00000347507	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461622 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 727120

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hypertrophic cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 15, 2018

This variant is not present in population databases (ExAC no frequency). This sequence change replaces serine with tryptophan at codon 4 of the MYH7 protein (p.Ser4Trp). The serine residue is weakly conserved and there is a large physicochemical difference between serine and tryptophan. 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 variant has not been reported in the literature in individuals with MYH7-related disease. However, a different sequence change affecting the same codon, p.Ser4Leu, has been reported in individuals affected with hypertrophic cardiomyopathy (PMID: 19150014, 22765922, 25342278). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.42
CardioboostCm	Benign	0.018
BayesDel_addAF	Uncertain	0.067	T
BayesDel_noAF	Benign	-0.14
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Benign	0.39	T
Eigen	Benign	-0.052
Eigen_PC	Benign	-0.045
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.77	D
MetaRNN	Pathogenic	0.76	D
MetaSVM	Uncertain	0.058	D
MutationAssessor	Benign	0.84	L
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.49	T
PROVEAN	Benign	-2.3	N
REVEL	Uncertain	0.43
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.060	T
Polyphen		0.92	P
Vest4		0.35
MutPred		0.46		Loss of disorder (P = 0);
MVP		0.94
MPC		2.0
ClinPred		0.80	D
GERP RS		4.1
Varity_R		0.53
gMVP		0.60

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs758659692; hg19: chr14-23902931;