rs398124034

Positions:

• chrX-32699264-ACTT-A

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM2 PM4_Supporting PP5_Very_Strong

The ENST00000357033.9(DMD):​c.676_678del​(p.Lys226del) variant causes a inframe deletion change involving the alteration of a conserved nucleotide. 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. K226K) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 23)
• Consequence: DMD ENST00000357033.9 inframe_deletion
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 7.52

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 11 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in ENST00000357033.9. Strenght limited to Supporting due to length of the change: 1aa.
• PP5: Variant X-32699264-ACTT-A is Pathogenic according to our data. Variant chrX-32699264-ACTT-A is described in ClinVar as [Pathogenic]. Clinvar id is 94746.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chrX-32699264-ACTT-A is described in Lovd as [Pathogenic]. Variant chrX-32699264-ACTT-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DMD	NM_004006.3	c.676_678del	p.Lys226del	inframe_deletion	8/79	ENST00000357033.9	NP_003997.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DMD	ENST00000357033.9	c.676_678del	p.Lys226del	inframe_deletion	8/79	1	NM_004006.3	ENSP00000354923	P4

Frequencies

GnomAD3 genomes Cov.: 23

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jul 07, 2023	Published functional studies demonstrate decreased dystrophin on Western blot (Aartsma-Rus et al., 2006); In-frame deletion of 1 amino acids in a non-repeat region predicted to critically alter the protein length. Deleted amino acid residue is predicted to be within the CH domain 2 in the actin binding domain; In silico analysis supports a deleterious effect on protein structure/function; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 21515508, 19937601, 27582364, 20485447, 33101180, 33644936, 29973226, 19760747) -
Pathogenic, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jan 21, 2016	- -

Duchenne muscular dystrophy Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 16, 2023

For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 94746). This variant has been observed in individuals with Becker/Duchenne muscular dystrophy (PMID: 19760747, 20485447, 21515508, 27582364). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This variant, c.676_678del, results in the deletion of 1 amino acid(s) of the DMD protein (p.Lys226del), but otherwise preserves the integrity of the reading frame. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.17		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: rs398124034; hg19: chrX-32717381;