Muscular System Diseases | Duchenne Muscular Dystrophy

Posted on May 17, 2014 in Health

Muscular system diseases can affect the muscles that help us run, move, hold things, eat, walk, talk and cause numerous problems that damage the mobility and functioning of the body. Duchenne muscular dystrophy (DMD) is a condition that starts in childhood and causes muscle weakness. Because it is a recessive X-linked disease, it affects only boys, although girls can be carriers. Symptoms start before the age 6 and develop gradually.


DMD is one of the muscular system diseases that causes muscle weakness associated with muscle wasting. Voluntary muscles are the first to be affected in the pelvic area, shoulders, calf muscles, hips and tights. Patients tend to walk and run in an awkward manner, on their forefeet because of the enlarged calves and on their toes to compensate the knee extensors weakness. Running, jumping and hopping are difficult for affected children and they can often fall.

Other symptoms include fatigue, muscle fiber deformities, increased Lumbar lordosis, higher risk of neurobehavioral disorders such as ADHD, learning disorders, delayed speech development, skeletal deformities and loss of the ability to walk (around age 12). The boy might use his hands to get up as he gets older, climbing them up his legs (Gower’s sign). When you pick him up you might feel he is slipping through your hands because of the loose shoulder muscles.

The cause of Duchenne muscular dystrophy is a mutation of the dystrophin gene at locus Xp2, responsible with the connection between each muscle fiber to the underlying basal lamina and the cytoskeleton. The daughter of a carrier mother has a 50% chance to be a carrier herself, and the son of a carrier mother has a 50% chance if inheriting the gene. Sometimes carriers of a X-linked recessive condition can show some some symptoms.

Some physicians believe that the condition can be diagnosed when the child takes his first steps, because the muscle wasting begins in the pelvis and legs. By the age of 21 most patients are paralyzed from the neck down. Genetic testing, a muscle biopsy or prenatal tests can confirm the diagnosis. Prenatal tests can indicate if the fetus has the mutation, although a less invasive method is determining the sex on the child.

These types of muscular system diseases have no specific cure, therefore the treatment aims to maximize the quality of life and to control the symptoms. Some clinical trials produced a small improvement with walking but more experimental gene treatment options are being developed. Beta2-agonists increase muscle strength but do not stop the disease from progressing. Physical therapy and activities such as swimming are beneficial.