Muscular dystrophy, in which the body's muscles are abnormally weak, is a hereditary condition. The genetic causes of muscular dystrophy are specific to the type of dystrophy the patient suffers. In general, abnormalities in an individual's genes inhibit his ability to build and maintain healthy muscles. Dystrophia myotonica (DM), for example, is linked to defects in chromosomes 3 and 19. Although researchers have yet to develop treatments that effectively address the genetic causes of muscular dystrophy, proper exercise and therapy can delay degenerative effects.
Among the many different genetic causes of muscular dystrophy, a defect in the gene dystrophia myotonica protein kinase (DMPK) is the most common. In some individuals, the cytosine-thymine-guanine triplet found in DMPK repeats abnormally, resulting in type 1 dystrophia myotonica (DM1). DM1 accounts for nearly 98% of dystrophia myotonica cases. Type 2 dystrophia myotonica (DM2), on the other hand, is caused by a repeat in the cytosine-cytosine-thymine-guanine (CCTG) chain in the zinc finger protein 9 (ZFN9) gene. Both DM1 and DM2 are among the majority of adult muscular dystrophy cases.
Another very common type of muscular dystrophy is Duchenne muscular dystrophy (DMD). In DMD, the genetic causes of muscular dystrophy are mutations in the dystrophin gene. The abnormality induces several complex reactions that eventually lead to muscle fiber death. Mutations in the dystrophin gene can also result in Becker's muscular dystrophy, a less severe relative of DMD. These irregularities can be caused by a number of influences, including toxic substances that damage developing fetuses in the womb.
The genetic causes of muscular dystrophy are generally untreatable, though continuing research shows promise. In the case of DM1, for example, genetic splicing has allowed researchers to replicate and reverse the condition in mice. Similar research is being conducted on the other genetic causes of muscular dystrophy, bearing mixed results.
Treatment for muscular dystrophy serves mainly to help patients manage the symptoms and sustain a decent quality of life. Medication, such as corticosteroids, can help boost the patient's strength to workable levels. Treatment is often coupled with regular physical therapy in order to improve muscle tone and delay cell degeneration. If the condition progresses to severe levels, it becomes necessary to supplement the patient's oxygen supplies through assisted respiration, as the muscle failure makes breathing difficult. Although muscular dystrophy can be extremely debilitating in serious cases, modern treatment makes it possible for individuals afflicted with the disease to cope with the symptoms.