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Duchenne and Becker Muscular Dystrophy (DMD/BMD)
Duchenne Muscular Dystrophy is one of the most common inherited disorders worldwide. It is a disorder that affects boys almost exclusively. Parents may first see that their three-to-five year old child has frequent falls, runs slowly, or has toe-walking or a waddling gait. The child’s calves are often unusually large. Weakness is initially most pronounced in the hips and upper leg muscles, but will include most voluntary muscles over time, including those responsible for respiration. The heart similarly becomes weak over time. Weakness of the heart and respiratory muscles make this a fatal disorder that requires careful medical management. Becker muscular dystrophy is similar to Duchenne in that it can cause weakness of the skeletal muscles, muscles of respiration, and heart, but the symptoms are usually less severe.
Both Duchenne and Becker muscular dystrophy are caused by mutations in a protein called dystrophin. In Duchenne muscular dystrophy, functioning dystrophin is completely absent in muscle, while in Becker muscular dystrophy, there is some dystrophin present, although not enough for completely normal muscle function.
Diagnosis is based on the history of disease, including a family history, clinical features found during examination, and supporting laboratory data. Mutations in the dystrophin gene can be detected by a genetic blood test. In most cases of Duchenne and Becker muscular dystrophy, the mutation is inherited from the child's mother, who carries the disease gene but does not have symptoms; in other cases, the mutation occurs spontaneously. Our genetic counselor will carefully review the history of disease with each family, discuss the principles of inheritance and help weigh risks and benefits of genetic testing of various family members, including the patient and the mother.
The treatment of DMD/BMD requires active participation from health care providers, parents and schools to ensure that each child thrives. Most children with DMD are placed on corticosteroids, which have been shown in clinical trials to decrease the rate of decline in strength. A neurologist on our team will manage this treatment and help minimize side effects of the drug. The neurologist also directs and coordinates care among a variety of services. Physical and occupational rehabilitation play a large role in designing exercise programs and teaching stretching activities to minimize limiting contractures. Severe contractures and scoliosis are treated by orthopedic surgeons on our team who have extensive experience with DMD. Heart function is followed through EKGs and echocardiograms reviewed by a cardiologist. An endocrinologist on the team manages hormonal issues and bone health. The Center for Genetic Muscle Disorders is designed to maximize independent function and minimize complications of DMD. We welcome the opportunity to work with families living with DMD.