14-23412864-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 5P and 2B. PM1 PM2 PP2 BP4_Moderate

The NM_000257.4(MYH7):c.5798A>G(p.Asn1933Ser) 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. 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. N1933H) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: MYH7 NM_000257.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 2.59

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.

• PM1: In a region_of_interest Disordered (size 28) in uniprot entity MYH7_HUMAN there are 17 pathogenic changes around while only 2 benign (89%) in NM_000257.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, MYH7
• BP4: Computational evidence support a benign effect (MetaRNN=0.122276306).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
MYH7	NM_000257.4	c.5798A>G	p.Asn1933Ser	missense_variant	40/40	ENST00000355349.4
MYH7	NM_001407004.1	c.5798A>G	p.Asn1933Ser	missense_variant	39/39

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MYH7	ENST00000355349.4	c.5798A>G	p.Asn1933Ser	missense_variant	40/40	1	NM_000257.4	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

May 16, 2022

This missense variant replaces asparagine with serine at codon 1933 of the MYH7 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Hypertrophic cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Dec 06, 2020

This variant has not been reported in the literature in individuals with MYH7-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces asparagine with serine at codon 1933 of the MYH7 protein (p.Asn1933Ser). The asparagine residue is highly conserved and there is a small physicochemical difference between asparagine and serine. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.057
CardioboostCm	Benign	0.027
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.39
Cadd	Benign	19
Dann	Benign	0.90
DEOGEN2	Benign	0.26	T
Eigen	Benign	-0.52
Eigen_PC	Benign	-0.24
FATHMM_MKL	Uncertain	0.81	D
LIST_S2	Benign	0.74	T
M_CAP	Uncertain	0.13	D
MetaRNN	Benign	0.12	T
MetaSVM	Benign	-0.67	T
MutationAssessor	Benign	-1.4	N
MutationTaster	Benign	0.77	D
PrimateAI	Uncertain	0.57	T
PROVEAN	Benign	0.24	N
REVEL	Benign	0.24
Sift	Benign	1.0	T
Sift4G	Benign	1.0	T
Polyphen		0.020	B
Vest4		0.27
MutPred		0.13		Gain of catalytic residue at L1932 (P = 0);
MVP		0.69
MPC		0.46
ClinPred		0.39	T
GERP RS		5.4
Varity_R		0.082
gMVP		0.40

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr14-23882073;