chrX-32816504-T-A

Position:

• chrX-32816504-T-A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_004006.3(DMD):​c.494A>T​(p.Asp165Val) variant causes a missense change involving the alteration of a 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 (★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: DMD NM_004006.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter P:1 U:1
• Conservation: PhyloP100: 8.01

Genes affected

DMD (HGNC:2928): (dystrophin) This gene spans a genomic range of greater than 2 Mb and encodes a large protein containing an N-terminal actin-binding domain and multiple spectrin repeats. The encoded protein forms a component of the dystrophin-glycoprotein complex (DGC), which bridges the inner cytoskeleton and the extracellular matrix. Deletions, duplications, and point mutations at this gene locus may cause Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), or cardiomyopathy. Alternative promoter usage and alternative splicing result in numerous distinct transcript variants and protein isoforms for this gene. [provided by RefSeq, Dec 2016]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a region_of_interest Actin-binding (size 239) in uniprot entity DMD_HUMAN there are 5 pathogenic changes around while only 1 benign (83%) in NM_004006.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DMD	NM_004006.3	c.494A>T	p.Asp165Val	missense_variant	6/79	ENST00000357033.9	NP_003997.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DMD	ENST00000357033.9	c.494A>T	p.Asp165Val	missense_variant	6/79	1	NM_004006.3	ENSP00000354923	P4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Becker muscular dystrophy Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Institute of Human Genetics, University of Wuerzburg

-

- -

Duchenne muscular dystrophy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 06, 2018

This sequence change replaces aspartic acid with valine at codon 165 of the DMD protein (p.Asp165Val). The aspartic acid residue is highly conserved and there is a large physicochemical difference between aspartic acid and valine. This variant is not present in population databases (ExAC no frequency). This variant has been reported in individuals affected with Becker muscular dystrophy (PMID: 12632325, Invitae). Experimental studies have shown that this missense change increases protein aggregation and thermal denaturation but does not significantly affect actin-binding affinity (PMID: 20457930). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.91
BayesDel_addAF	Pathogenic	0.74	D
BayesDel_noAF	Pathogenic	0.82
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.90	.;D;.;.;D
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;.;D;D;D
M_CAP	Pathogenic	0.87	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.70	T
PROVEAN	Pathogenic	-6.7	.;D;.;D;D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	.;D;.;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D
Polyphen		1.0	.;D;.;.;D
Vest4		0.99
MutPred		0.94		.;.;Gain of helix (P = 0.2059);Gain of helix (P = 0.2059);.;
MVP		1.0
MPC		0.13
ClinPred		1.0	D
GERP RS		5.5
gMVP		0.95

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1557052542; hg19: chrX-32834621;