Muscular Dystrophy (MD)

Muscular dystrophy (MD) is a group of muscle diseases that results in increasing weakening and breakdown of skeletal muscles over time.[1] The disorders differ in which muscles are primarily affected, the degree of weakness, how fast they worsen, and when symptoms begin.[1] Many people eventually become unable to walk. Some types are also associated with problems in other organs.[2]

There are nine main categories of muscular dystrophy that contain more than thirty specific types.[1][2] The most common type is Duchenne muscular dystrophy (DMD) which typically affects males beginning around the age of four. Other types include Becker muscular dystrophy, facioscapulohumeral muscular dystrophy, and myotonic dystrophy.[1] They are due to mutations in genes that are involved in making muscle proteins. This can occur due to either inheriting the defect from one's parents or the mutation occurring during early development. Disorders may be X-linked recessive, autosomal recessive, or autosomal dominant. Diagnosis often involves blood tests and genetic testing.[2]