Muscular dystrophy

Alternative names:

inherited myopathy; MD

Definition:

A group of disorders characterized by progressive muscle weakness and loss of muscle tissue.

Causes, incidence, and risk factors:

The group of diseases called muscular dystrophies includes many inherited disorders such as:

• Becker's muscular dystrophy
• Duchenne's muscular dystrophy
• facioscapulohumeral muscular dystrophy
• limb-girdle muscular dystrophy
• Emery-Dreifuss muscular dystrophy
• myotonic dystrophy
• myotonia congenita

Disorders are distinguished by the type of inheritance ( sex-linked, dominant genes , or recessive gene, and so on), the age when symptoms appear, and the types of symptoms that develop. Because these are inherited disorders, risks include a family history of muscular dystrophy.

Lambert-Eaton syndrome and myasthenia gravis have symptoms that may be similar to early stages of some types of muscular dystrophies.