Duchenne Muscular Dystrophy is a fatal, genetic, muscle-wasting disease affecting about one in every 5,000 boys. Because the Duchenne gene is found on the X-chromosome, it primarily affects males. Girls can get Duchenne but it is very rare. Mothers can be carriers but approximately 1 out of 3 times it occurs due to a random, spontaneous mutation. Duchenne affects skeletal, heart, and lung muscles. Muscle loss is typically first noticed during childhood in the hips, thighs, shoulders and pelvis. The arms, lower legs and trunk are typically affected by the early teen years and usually by that time a wheelchair is needed full time (the age for loss of ambulation varies). Eventually, heart function and breathing are affected because there is an absence of dystrophin in the muscles of the hearts and lungs. Duchenne is caused by a mutation in the gene that encodes for a protein called dystrophin. Without dystrophin, muscles are not able to function or repair themselves properly.