Muscular dystrophy is usually diagnosed in children between 3 and 6 years of age. What are the symptoms of muscular dystrophy? For example, a woman can carry a recessive gene on one of the X chromosomes unknowingly, and pass it on to a son, who will express the trait or disease. However, for males there only needs to be one copy of an X-linked recessive gene in order for the trait or disorder to be expressed. X-linked recessive genes are expressed in females only if there are two copies of the gene (one on each X chromosome). Genes on the X chromosome can be recessive or dominant, and their expression in females and males is not the same because the genes on the Y chromosome do not exactly pair up with the genes on the X. "X-linked" means that the gene causing the trait or the disorder is located on the X chromosome. The first 22 pairs are shared in common between males and females, while the last pair determine gender and are called the sex chromosome pair: females have two X chromosomes, while males have one X and one Y chromosome.ĭuchenne muscular dystrophy is caused by an X-linked recessive gene. There are normally 46 chromosomes in each cell of our body, or 23 pairs.
Genes are contained in the cells of our bodies on stick-like structures called chromosomes. Our genes determine our traits, such as eye color and blood type. What causes muscular dystrophy?ĭuchenne muscular dystrophy is a genetic disease which means it is inherited. Girls are rarely affected by either of these two forms of muscular dystrophy. The two forms are very similar, but Becker muscular dystrophy is less severe than DMD. The most common forms of muscular dystrophy are Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy. A lateral, or sideways, curvature and rotation of the back bones (vertebrae), giving the appearance that the person is leaning to one side. Other health problems commonly associated with muscular dystrophy include the following: The muscles break down and are replaced with fatty deposits over time. Muscular dystrophy causes the muscles in the body to become very weak. Muscular dystrophy (MD) is a broad term that describes a genetic (inherited) disorder of the muscles.