14-23427868-T-G

Position:

• chr14-23427868-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP2 PP3

The ENST00000355349.4(MYH7):​c.1605A>C​(p.Glu535Asp) 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. E535K) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: MYH7 ENST00000355349.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.328

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 8 ACMG points.

• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 10 uncertain in ENST00000355349.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr14-23427870-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1301885.Status of the report is criteria_provided_single_submitter, 1 stars.
• 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, 0.783

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MYH7	NM_000257.4	c.1605A>C	p.Glu535Asp	missense_variant	16/40	ENST00000355349.4	NP_000248.2
MYH7	NM_001407004.1	c.1605A>C	p.Glu535Asp	missense_variant	15/39		NP_001393933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MYH7	ENST00000355349.4	c.1605A>C	p.Glu535Asp	missense_variant	16/40	1	NM_000257.4	ENSP00000347507	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

Hypertrophic cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 16, 2020

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. 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). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has been observed in individual(s) with MYH7-related conditions (Invitae). This variant is not present in population databases (ExAC no frequency). This sequence change replaces glutamic acid with aspartic acid at codon 535 of the MYH7 protein (p.Glu535Asp). The glutamic acid residue is highly conserved and there is a small physicochemical difference between glutamic acid and aspartic acid. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
CardioboostCm	Pathogenic	0.96
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.060
CADD	Benign	18
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.86	D
Eigen	Benign	-0.68
Eigen_PC	Benign	-0.58
FATHMM_MKL	Benign	0.55	D
LIST_S2	Uncertain	0.90	D
M_CAP	Pathogenic	0.50	D
MetaRNN	Pathogenic	0.78	D
MetaSVM	Benign	-0.72	T
MutationAssessor	Benign	0.32	N
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.78	T
PROVEAN	Uncertain	-2.6	D
REVEL	Uncertain	0.54
Sift	Uncertain	0.012	D
Sift4G	Benign	0.79	T
Polyphen		0.0010	B
Vest4		0.75
MutPred		0.63		Gain of catalytic residue at I530 (P = 5e-04);
MVP		0.74
MPC		2.0
ClinPred		0.65	D
GERP RS		1.0
Varity_R		0.54
gMVP		0.92

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: rs2069543; hg19: chr14-23897077;