rs398123909

chrX-32472310-C-AchrX-32472310-C-GchrX-32472310-C-T

Variant summary

Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PVS1 PM2 PP3_Strong PP5_Very_Strong

The NM_004006.3(DMD):c.2804-1G>T variant causes a splice acceptor 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: DMD NM_004006.3 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 7.36

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 22 ACMG points.

• PVS1: Splicing variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 4.3, offset of 32, new splice context is: tgccaccaatgcgctatcAGgag. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant X-32472310-C-A is Pathogenic according to our data. Variant chrX-32472310-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 455886.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chrX-32472310-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DMD	NM_004006.3	c.2804-1G>T		splice_acceptor_variant		ENST00000357033.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DMD	ENST00000357033.9	c.2804-1G>T		splice_acceptor_variant		1	NM_004006.3	P4

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Duchenne muscular dystrophy Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	May 06, 2018	This sequence change affects an acceptor splice site in intron 21 of the DMD gene. It is expected to disrupt RNA splicing and likely results in an absent or disrupted protein product. This variant is not present in population databases (ExAC no frequency). This variant has been reported in individuals affected with Duchene Muscular Dystrophy (PMID: 16770791, 23453023, 28859693). In one of these individuals this variant was reported to be de novo (PMID: 16770791). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site, but this prediction has not been confirmed by published transcriptional studies. Donor and acceptor splice site variants typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in DMD are known to be pathogenic (PMID: 16770791, 23453023, 25007885). For these reasons, this variant has been classified as Pathogenic. -
Likely pathogenic, no assertion criteria provided	clinical testing	Counsyl	Sep 22, 2017	- -

Becker muscular dystrophy Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

Counsyl

Sep 22, 2017

- -

Dilated cardiomyopathy 3B Pathogenic:1

Likely pathogenic, no assertion criteria provided

clinical testing

Counsyl

Sep 22, 2017

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Jun 14, 2017

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.20
Cadd	Pathogenic	32
Dann	Uncertain	0.99
FATHMM_MKL	Uncertain	0.97	D
MutationTaster	Benign	1.0	D;D
GERP RS		5.0

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.98		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.79		Position offset: -33
DS_AL_spliceai		0.98		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs398123909; hg19: chrX-32490427;