Several major forms of muscular dystrophy can affect teens, each of which weakens different muscle groups in various ways:
•Duchenne muscular dystrophy (DMD): Duchenne muscular dystrophy (DMD) is the most common type of the disease, is caused by a problem with the gene that makes a protein called dystrophin. This protein helps muscle cells keep their shape and strength. Without it, muscles break down and a person gradually becomes weaker. DMD affects boys. Symptoms start between ages 2 and 6. By age 10 or 12, kids with DMD often need to use a wheelchair. The heart may also be affected, and people with DMD need to be followed closely by a lung and heart specialist.
• Becker muscular dystrophy (BMD): Becker muscular dystrophy (BMD) is like DMD, affects boys. The disease is very similar to DMD, but its symptoms may start later and can be less severe. With BMD, symptoms like muscle breakdown and weakness sometimes don't begin until age 10 or even in adulthood. People with BMD can also have breathing, heart, bone, muscle, and joint problems. Many people with BMD can live long, active lives without using a wheelchair.
Emery-Dreifuss muscular dystrophy (EDMD): Emery-Dreifuss muscular dystrophy (EDMD) starts causing symptoms in late childhood to early teens and sometimes as late as age 25. EDMD is another form of muscular dystrophy that affects mostly boys. It involves muscles in the shoulders, upper arms, and shins, and it often causes joint problems (joints can become tighter in people with EDMD). The heart muscle may als be affected.
Limb-girdle muscular dystrophy (LGMD): Limb-girdle muscular dystrophy (LGMD affects boys and girls equally, weakening muscles in the shoulders and upper arms and around the hips and thighs. LGMD can begin as early as childhood or as late as mid adulthood and it often progresses slowly.
Facioscapulohumeral muscular dystrophy (FSHD): Facioscapulohumeral muscul dystrophy (FSHD) can affect both guys and girls, and it usually begins during the teens or early adulthood. FSHD affects muscles in the face and shoulders and sometimes causes weakness in the lower legs. People with this type of MD have trouble raising their arms, whistling, or tightly closing their eyes.
Myotonic dystrophy (MMD): Myotonic dystrophy (MMD) is a form of muscular dystrophy in which the muscles have difficulty relaxing. In teens, it can cause a number of problems, including muscle weakness and wasting (where the muscles shrink over time), cataracts, and heart problems.
Congenital muscular dystrophy (CMD): Congenital muscular dystrophy (CMD) is the term for all types of MD that show signs in babies and young children, although the MD isn't always diagnosed right away. Like other forms of MD, CMD involves muscle weakness and poor muscle tone. Occurring in both girls and boys, it can have different symptoms. It varies in how severely it affects people and how quickly or slowly it worsens.