Duchenne Muscular Dystrophy (DMD) is a severe genetic disorder characterized by progressive muscle degeneration and weakness. It is caused by mutations in the dystrophin gene, which encodes the protein dystrophin. Dystrophin is essential for maintaining the structural integrity of muscle cells. The lack of functional dystrophin leads to muscle damage, inflammation, and eventual replacement of muscle tissue with fat and fibrotic tissue.
Key Features and Progression of DMD:
- Early Childhood: Symptoms usually appear between ages 2 and 5. Early signs include difficulty in walking, running, jumping, and climbing stairs. Children may also exhibit a waddling gait and frequent falls.
- School Age: Muscle weakness progressively worsens, affecting the arms, legs, and trunk. By age 12, most children with DMD are unable to walk and require a wheelchair.
- Adolescence to Adulthood: Complications such as scoliosis, respiratory issues, and cardiomyopathy (heart muscle disease) develop. Lifespan is significantly shortened, often due to heart or respiratory failure.
Diagnosis and Treatment:
- Diagnosis: Includes genetic testing to identify mutations in the dystrophin gene, muscle biopsy, and blood tests for elevated levels of creatine kinase.
- Treatment: While there is no cure for DMD, treatments aim to manage symptoms and improve quality of life. These include corticosteroids to slow muscle degeneration, physical therapy, respiratory support, and cardiac care. Emerging therapies, such as exon skipping and gene therapy, are being researched to target the underlying genetic cause.