rs1556917057

Positions:

• chrX-31820015-CT-C

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_004006.3(DMD):​c.7268del​(p.Lys2423SerfsTer5) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. K2423K) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 24)
• Consequence: DMD NM_004006.3 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 3.95

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 Pathogenic. Variant got 18 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
• PP5: Variant X-31820015-CT-C is Pathogenic according to our data. Variant chrX-31820015-CT-C is described in ClinVar as [Pathogenic]. Clinvar id is 455931.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DMD	NM_004006.3	c.7268del	p.Lys2423SerfsTer5	frameshift_variant	50/79	ENST00000357033.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DMD	ENST00000357033.9	c.7268del	p.Lys2423SerfsTer5	frameshift_variant	50/79	1	NM_004006.3	P4

Frequencies

GnomAD3 genomes Cov.: 24

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 24

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Apr 19, 2017

- -

Duchenne muscular dystrophy Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Mar 21, 2017

While this particular variant has not been reported in the literature, loss-of-function variants in DMD are known to be pathogenic (PMID: 16770791). This sequence change deletes 1 nucleotide from exon 50 of the DMD mRNA (c.7268delA), causing a frameshift at codon 2423. This creates a premature translational stop signal (p.Lys2423Serfs*5) and is expected to result in an absent or disrupted protein product. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

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: rs1556917057; hg19: chrX-31838132;