DMD (Dystrophin) Gene: Structure, Function, and Clinical Significance
Comprehensive resource on the DMD gene, encoding dystrophin, its role in muscle integrity, associated disorders, expression patterns, and mutation landscape.
Gene Information Card
| Symbol | DMD |
|---|---|
| Full Name | Dystrophin |
| Gene Type | Protein coding |
| Chromosomal Location | Xp21.2-p21.1 |
| NCBI Gene ID | 1756 ncbi.nlm.nih.gov/gene/1756 |
| Ensembl ID | ENSG00000198947 |
| UniProt ID | P11532 |
| OMIM ID | 300377 |
| HGNC ID | 2928 |
| Aliases | DXS142, DXS164, DXS206, DXS230, DXS239, DXS268, DXS269, DXS270, DXS272 |
Description
The DMD gene encodes dystrophin, a large cytoskeletal protein that links the actin cytoskeleton to the extracellular matrix via the dystrophin-associated glycoprotein complex (DAPC). This linkage is essential for maintaining muscle fiber integrity during contraction. Mutations in DMD cause Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD), and X-linked dilated cardiomyopathy (XLDC). The gene is one of the largest in the human genome, spanning ~2.2 Mb, and has multiple tissue-specific promoters and alternative splicing isoforms.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Duchenne muscular dystrophy (DMD) | Out-of-frame deletions or nonsense mutations lead to complete loss of dystrophin, disrupting the DAPC and causing muscle fiber necrosis. | ClinVar, OMIM |
| Becker muscular dystrophy (BMD) | In-frame deletions or missense mutations produce a partially functional dystrophin, resulting in a milder phenotype with later onset. | ClinVar, OMIM |
| X-linked dilated cardiomyopathy (XLDC) | Mutations affecting the cardiac isoform of dystrophin (e.g., in the muscle promoter or exon 1) cause isolated cardiomyopathy without skeletal muscle involvement. | ClinVar, OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skeletal muscle | High (nTPM ~ 100) | High |
| Heart muscle | High (nTPM ~ 80) | High |
| Brain | Low (nTPM ~ 5) | Low |
| Smooth muscle | Moderate (nTPM ~ 20) | Moderate |
| Liver | Not detected | Absent |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Skeletal muscle myotubes | High | Differentiated muscle cells show strong expression |
| Cardiomyocytes | High | Essential for cardiac function |
| Fibroblasts | Low | Minimal expression in undifferentiated cells |
| HeLa (cervical cancer) | Not detected | Non-muscle cell line lacks expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| Exonic deletion (out-of-frame) | Deletion | ~60-70% of DMD cases | Complete loss of dystrophin, severe phenotype |
| Nonsense mutation | Point mutation | ~10-15% of DMD cases | Premature stop codon, truncated protein |
| Exonic deletion (in-frame) | Deletion | ~80% of BMD cases | Partially functional dystrophin, milder phenotype |
| Missense mutation | Point mutation | Rare | Variable effect, often mild or cardiac-specific |
Mutation functional classification
Loss of Function (LOF)
Most DMD mutations are loss-of-function, leading to absent or non-functional dystrophin. This disrupts the DAPC, causing membrane instability and muscle degeneration.
Gain of Function (GOF)
No gain-of-function mutations are described for DMD; the gene is not oncogenic.
Dominant Negative (DN)
Not applicable; DMD is X-linked recessive, and mutations are typically recessive. However, some rare dominant-negative effects have been suggested in specific isoforms, but evidence is limited.
View complete mutation data：
Gene Ontology (GO)
| • actin binding | • structural constituent of muscle |
| • protein binding | • cytoskeleton organization |
| • muscle contraction | • cell adhesion |
| • signal transduction |
Pathways
• Dystrophin-associated glycoprotein complex (DAPC) signaling
• Muscle contraction and sarcomere organization
• Cytoskeletal anchoring to extracellular matrix
• Calcium homeostasis and signaling in muscle
Protein Summary
Dystrophin is a 427 kDa rod-shaped protein with an N-terminal actin-binding domain, a central spectrin-like repeat region, and a C-terminal domain that interacts with dystroglycans and syntrophins. It localizes to the sarcolemma and stabilizes the muscle membrane. Alternative promoters produce isoforms in brain (Dp427c), retina, and other tissues. Loss of dystrophin leads to membrane fragility, increased calcium influx, and muscle necrosis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| DMD Knockout HEK293 Cell Line | EDJ-KQ3154 | Human | 1756 | Details Get a Quote |
| GSDMD Knockout HEK293 Cell Line | EDJ-KQ12933 | Human | 79792 | Details Get a Quote |
| DMD Knockout HeLa Cell Line | EDJ-KQ24552 | Human | 1756 | Details Get a Quote |
| GSDMD Knockout A-549 Cell Line | EDJ-KQ43393 | Human | 79792 | Details Get a Quote |
| GSDMD Knockout HCT 116 Cell Line | EDJ-KQ43395 | Human | 79792 | Details Get a Quote |
| GSDMD Knockout HeLa Cell Line | EDJ-KQ43396 | Human | 79792 | Details Get a Quote |
| GSDMD Knockout HTR-8/SVneo Cell Line | EDJ-KZ273 | Human | 79792 | Details Get a Quote |
| GSDMD Knockout THP-1 Cell Line | EDJ-KZ274 | Human | 79792 | Details Get a Quote |
| DMD Knockout A-549 Cell Line | EDJ-KQ61566 | Human | 1756 | Details Get a Quote |
| DMD Knockout HCT 116 Cell Line | EDJ-KQ70057 | Human | 1756 | Details Get a Quote |
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