Associated disorders

The DMD gene is associated with X-linked Duchenne muscular dystrophy (DMD) (MedGen UID: 3925), Becker muscular dystrophy (BMD) (MedGen UID: 182959), and dilated cardiomyopathy (DCM) (MedGen UID: 777148).

DMD is the only known cause of Duchenne and Becker muscular dystrophies. Test sensitivity is high when quantitative analysis and gene sequencing are combined. Deletion/duplication testing will detect approximately 55%-75% of the pathogenic DMD variants in Duchenne patients and slightly more (75%-90%) in Becker patients. Sequence analysis of DMD will detect an additional 20%-35% of Duchenne cases and 10%-20% of Becker cases. Relative contribution to dilated cardiomyopathy by DMD is unknown but is likely implicated in less than 1% of all cases of DCM.

DMD encodes dystrophin, a large cytoplasmic protein that bridges the intracellular cytoskeleton and the extracellular matrix by binding to actin at its C-terminus and dystroglycan at its N-terminus.

Assay and technical information

Invitae is a College of American Pathologists (CAP)-accredited and Clinical Laboratory Improvement Amendments (CLIA)-certified clinical diagnostic laboratory performing full-gene sequencing and deletion/duplication analysis using next-generation sequencing technology (NGS).

Our sequence analysis covers clinically important regions of each gene, including coding exons, +/- 10 base pairs of adjacent intronic sequence, and select noncoding variants. Our assay provides a Q30 quality-adjusted mean coverage depth of 350x (50x minimum, or supplemented with additional analysis). Variants classified as pathogenic or likely pathogenic are confirmed with orthogonal methods, except individual variants that have high quality scores and previously validated in at least ten unrelated samples.

Our analysis detects most intragenic deletions and duplications at single exon resolution. However, in rare situations, single-exon copy number events may not be analyzed due to inherent sequence properties or isolated reduction in data quality. If you are requesting the detection of a specific single-exon copy number variation, please contact Client Services before placing your order.

Gene Transcript reference Sequencing analysis Deletion/Duplication analysis
DMD* NM_004006.2

*DMD: Analysis guarantees del/dup detection at single-exon resolution.