Jennifer McNary, Rare Disease Advocate, explains why there is so much interest in Duchenne muscular dystrophy (DMD) and some of the future considerations for this rare disease.
Duchenne muscular dystrophy is a progressive form of muscular dystrophy that occurs primarily in males, though in rare cases may affect females. DMD causes progressive weakness and loss (atrophy) of skeletal and heart muscles. Early signs of DMD may include delayed ability to sit, stand, or walk and difficulties learning to speak. Muscle weakness is usually noticeable by 3 or 4 years of age and begins in the hips, pelvic area, upper legs, and shoulders. The calves may be enlarged. Children with DMD may have an unusual walk and difficulty running, climbing stairs, and getting up from the floor. DMD may also affect learning and memory, as well as communication and certain social emotional skills. Muscle weakness worsens with age and progresses to the arms, legs and trunk. Most children with DMD use a wheelchair full time by age 13. Heart and respiratory muscle problems begin in the teen years and lead to serious, life threatening complications.DMD is caused by changes (mutations) in the DMD gene. The DMD gene codes for the protein dystrophin. Dystrophin is mainly made in skeletal and heart muscle cells, but a small amount is also made in nerve cells (neurons) in specific parts of the brain. DMD is inherited in an X-linked recessive pattern; however, it may also occur in people who do not have a family history of DMD. While there is no known cure for DMD, there are treatments that can help control symptoms. Due to the advancement of medical treatment, boys with DMD may now live into young adulthood.
Duchenne muscular dystrophy occurs in one out of every 3,600 male infants, and is much rarer in girls.