Emery-Dreifuss muscular dystrophy (EDMD) is a condition affecting the joints, muscles and heart. It is named for Alan Emery and Fritz Dreifuss, physicians who first described the disorder among a Virginia family in the 1960s.
The symptoms of EDMD usually become apparent by 10 years of age. Characteristic symptoms include a triad of:
EDMD progresses slowly. Muscle weakness may not become a source of difficulty until later in life. Intellect is not affected.
EDMD can be caused by mutations in several genes that produce proteins in the membrane surrounding the nucleus of each muscle cell, and can be inherited in several different ways. Mutations in the EMD gene or, less commonly, in the FHL1 gene cause the X-linked type of the condition. Mutations in the LMNA gene cause both the autosomal dominant and autosomal recessive types of the condition. Other genes related to autosomal dominant EDMD include SYNE1, SYNE2 and TMEM43. Meanwhile, more than half of all EDMD patients have no identifiable genetic causes.
A diagnosis of EDMD is based upon a thorough clinical evaluation, a detailed patient and family history, identification of characteristic symptoms (contractures, myopathy, heart defects, etc.), surgical removal and microscopic study (biopsy) of affected tissue, and specialized tests such as immunodetection and molecular genetic testing. Genetic testing, usually using a blood sample, can be used to confirm the EDMD diagnosis and to identify a specific subtype.
No specific treatment exists for EDMD. Current treatment options are aimed at alleviating specific symptoms, and may include physical therapy and active and passive exercise to build muscle strength and prevent contractures. Surgery may be recommended in some cases to treat contractures or scoliosis. The use of mechanical aids (e.g., canes, braces, and wheelchairs) may become necessary to aid walking.