Muscular Dystrophy - What is Duchenne Muscular Dystrophy?

By Hilary Basile

Muscular dystrophy is an inherited disease. Different muscular dystrophies follow various inheritance patterns.

The best-known type, Duchenne muscular dystrophy (DMD), is inherited in an X-linked recessive pattern, meaning that the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes, and is thus considered sex-linked. In males (who have only one X chromosome) one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes) a mutation must generally be present in both copies of the gene to cause the disorder. This condition is much more common in males than in females.

A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons. In about two thirds of DMD cases, an affected male inherits the mutation from a mother who carries one altered copy of the DMD gene. The other one-third of cases probably results from new mutations in the gene. Females who carry one copy of a DMD mutation may have some signs and symptoms related to the condition (such as muscle weakness and cramping), but these are typically milder than the signs and symptoms seen in affected males.

Duchenne muscular dystrophy is the most severe form of dystrophinopathy. DMD is due to a genetic deficiency of the protein dystrophin. It is the most common form of muscular dystrophy that affects children. It is more common in young boys between the ages of 2 and 5. Signs and symptoms of Duchenne muscular dystrophy may include:

· Frequent falls

· Large calf muscles

· getting up from a lying or sitting position

· Weakness in lower leg muscles, resulting in difficulty running and jumping

· Waddling gait

· Mild mental retardation (in some cases)

Duchenne muscular dystrophy first affects the muscles of the pelvis, upper arms and upper legs. By late childhood, most children with DMD are unable to walk. Most die by their late teens or early 20s, often from pneumonia, respiratory muscle weakness or cardiac complications. Some people with DMD may exhibit curvature of their spine (scoliosis).

Hilary Basile is a writer for MyGuidesUSA.com http://www.myguidesusa.com, you will find valuable tips and resources for handling life's major events. Whether you're planning a wedding, buying your first home, anxiously awaiting the birth of a child, contending with a divorce, searching for a new job, or planning for your retirement, you'll find answers to your questions at MyGuidesUSA.com.

Find information on the causes and risk factors of muscular dystrophy, symptoms and types of muscular dystrophy, diagnosing muscular dystrophy, and treatment and care of muscular dystrophy at http://musculardystrophy.myguidesusa.com

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