Disease - Duchenne Muscular Dystrophy (DMD)

Duchenne Muscular Dystrophy 

Duchenne Muscular Dystrophy (DMD) is a condition when there is a loss of muscle function and weakness, usually starting from the lower limbs. It's rapidly progressive and usually happens in males. It is caused by a mutation in a gene (called the DMD gene) and can be inherited in families. The DMD gene is the second biggest gene and produces dystrophin. 

It affect approximately 1/3500 male births. 

Symptoms: 

The symptoms usually appear from infancy to age 6. Usually, the most first noticeable symptom is the delay of sitting and standing independently. Symptoms usually appear in boys aged 1 to 6. There is a steady decline in muscle strength between the ages of 6 and 11 years. By age 10, braces may be required for walking, and by age 12, most boys are confined to a wheelchair. Bones develop abnormally, causing skeletal deformities of the spine and other areas. This could lead to breathing disorders and cause cardiomyopathy and intellectual impairment. 

Most individuals that have DMD do not live past age 30. 

Diagnosis: 

By a muscle biopsy, where you take a sample of muscle, for dystrophin studies to look for abnormal levels of dystrophin in the muscles. The dystrophin can be detected by using a special dye. Someone diagnosed with DMD will lack dystrophin while someone who is not diagnosed with DMD will have dystrophin. 

You can also diagnose DMD by genetic testing on a blood sample for changes in the DMD gene. Genetic testing is constantly changing, but the methods currently being used look for large changes in the gene and another method, which looks at the letters that spell out the instructions found within the DMD gene. 

Treatment: 
The medication Prednisone (a steroid) is used to improve the strength and function of an individual with DMD. However, there are many side effects for this drug, which includes weight gain, high blood pressure, behavior  changes, and others. There are also many other similar medication to prednisone that has fewer side effects like Defalzacort and Cyclosporine. 

References - http://www.genome.gov/19518854