Dystrophinopathy

Dystrophinopathy is a group of genetic disorders characterized by progressive muscle weakness and degeneration. These conditions are caused by mutations in the DMD gene, which provides instructions for making a protein called dystrophin. Dystrophin is essential for maintaining the structural integrity of muscle cells. Its absence or deficiency leads to muscle fiber damage and inflammation.

The most common and severe form of dystrophinopathy is Duchenne muscular dystrophy (DMD). DMD typically affects boys and usually appears between the ages of 2 and 6 years. Symptoms include difficulty walking, frequent falls, enlarged calf muscles (pseudohypertrophy), and learning disabilities. Muscle weakness progresses, leading to loss of ambulation by the teenage years and affecting respiratory and cardiac muscles later in life.

A milder form is Becker muscular dystrophy (BMD). BMD also affects boys and men, but symptoms usually begin later in childhood or adolescence, and the progression of muscle weakness is slower. Individuals with BMD may retain the ability to walk into adulthood, and their lifespan is generally longer than those with DMD.

Diagnosis of dystrophinopathy involves genetic testing to identify mutations in the DMD gene and muscle biopsy to assess dystrophin levels. Currently, there is no cure for dystrophinopathy, but treatments focus on managing symptoms, slowing disease progression, and improving quality of life. These may include corticosteroids to reduce inflammation and muscle breakdown, physical therapy to maintain muscle function, and respiratory and cardiac support as needed. Research into gene therapy and other innovative treatments is ongoing.