NM_004006.3:c.2665C>T

Variant names:

• chrX-32485057-G-A
• rs1060502639
• NM_004006.3:c.2665C>T

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.2665C>T​(p.Arg889*) variant causes a stop gained change involving the alteration of a non-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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 23)
• Consequence: DMD NM_004006.3 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:8
• Conservation: PhyloP100: -0.120

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-32485057-G-A is Pathogenic according to our data. Variant chrX-32485057-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 409911.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chrX-32485057-G-A is described in Lovd as [Pathogenic]. Variant chrX-32485057-G-A is described in Lovd as [Likely_pathogenic]. Variant chrX-32485057-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DMD	NM_004006.3	c.2665C>T	p.Arg889*	stop_gained	Exon 21 of 79	ENST00000357033.9	NP_003997.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DMD	ENST00000357033.9	c.2665C>T	p.Arg889*	stop_gained	Exon 21 of 79	1	NM_004006.3	ENSP00000354923.3

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 23

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Mar 26, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The DMD c.2665C>T; p.Arg889Ter variant (rs1060502639; ClinVar ID: 409911) is reported in the literature in several individuals affected with Duchenne muscular dystrophy (Mah 2011, Taylor 2010). This variant is absent from the Genome Aggregation Database (v2.1.1), indicating it is not a common polymorphism. This variant induces an early termination codon and is predicted to result in a truncated protein or mRNA subject to nonsense-mediated decay. Based on available information, this variant is considered to be pathogenic. References: Mah JK et al. A population-based study of dystrophin mutations in Canada. Can J Neurol Sci. 2011 May;38(3):465-74. PMID: 21515508. Taylor PJ et al. Dystrophin gene mutation location and the risk of cognitive impairment in Duchenne muscular dystrophy. PLoS One. 2010 Jan 20;5(1):e8803. PMID: 20098710. -

Nov 07, 2022

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Duchenne muscular dystrophy Pathogenic:2

Dec 16, 2022

Laboratory of Medical Genetics, National & Kapodistrian University of Athens

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PVS1, PM2, PP5 -

Aug 24, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Arg889*) in the DMD gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in DMD are known to be pathogenic (PMID: 16770791, 25007885). For these reasons, this variant has been classified as Pathogenic. ClinVar contains an entry for this variant (Variation ID: 409911). This premature translational stop signal has been observed in individuals with Duchenne muscular dystrophy (PMID: 20098710, 21515508). This variant is not present in population databases (gnomAD no frequency). -

Qualitative or quantitative defects of dystrophin Pathogenic:1

Jun 03, 2019

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: DMD c.2665C>T (p.Arg889X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant was absent in 183384 control chromosomes (gnomAD). c.2665C>T has been reported in the literature in multiple individuals affected with Dystrophinopathies (Mah_2011, Okubo_2017, Xu_2017, Taylor_2010, Zengui_2018). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two ClinVar submissions from clinical diagnostic laboratories (evaluation after 2014) cite the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Becker muscular dystrophy Pathogenic:1

Nov 20, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Duchenne muscular dystrophy;C0878544:Cardiomyopathy;C0917713:Becker muscular dystrophy;na:Dystrophin deficiency Pathogenic:1

May 19, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Duchenne muscular dystrophy;C0917713:Becker muscular dystrophy;C3668940:Dilated cardiomyopathy 3B Pathogenic:1

Jun 07, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.51
CADD	Pathogenic	34
DANN	Uncertain	1.0
FATHMM_MKL	Benign	0.15	N
Vest4		0.93
GERP RS		0.47

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: rs1060502639; hg19: chrX-32503174; COSMIC: COSV63764262;