children s health issues
Duchenne Muscular Dystrophy and Becker Muscular Dystrophy
Introduction
Muscular dystrophies are a group of inherited muscle disorders in which one or more genes needed for normal muscle structure and function are defective, leading to Weakness of varying severity. Duchenne muscular dystrophy and Becker muscular dystrophy cause weakness in the muscles closest to the torso. They are the most common muscular dystrophies. These dystrophies are caused by defects in genes responsible for muscle function, which lead to muscle weakness that develops during childhood or adolescence, and nearly always occur in boys. Both dystrophies are characterized by physical weakness. The diagnosis is based on the results of tests done on samples of blood and a sample of muscle tissue. Treatment includes physical therapy and sometimes surgery for both dystrophies andprednisoneordeflazacortand sometimes other medications for Duchenne dystrophy. Duchenne muscular dystrophy and Becker muscular dystrophy are the most common muscular dystrophies. Duchenne muscular dystrophy is the most severe form of muscular dystrophy. It begins during early childhood. Becker muscular dystrophy, although closely related to Duchenne muscular dystrophy, begins later during adolescence and causes milder symptoms. These dystrophies nearly always occur in boys. Together, Duchenne muscular dystrophy and Becker muscular dystrophy affect about 1 of 5,000 to 1 of 6,000 live male births. Most affected people have Duchenne muscular dystrophy. gene. The gene for either of these traits is recessive and is carried on the X chromosome. Therefore, although a female can carry the defective gene, she will not develop the disorder because the normal gene on one X chromosome compensates for the gene defect on the other X chromosome. However, any male who receives the defective gene from the mother will have the disorder because males have only one X chromosome (see X-Linked Inheritance ). Boys with Duchenne muscular dystrophy lack almost all of the muscle protein dystrophin, which is important for maintaining the structure of muscle cells. Boys with Becker muscular dystrophy produce dystrophin, but because the protein structure is altered, the dystrophin does not function properly or the amount of dystrophin is insufficient. 