The symptoms and age of onset depend on the type of muscular dystrophy. Symptoms of muscular dystrophy often include:
- problems with coordination and mobility with frequent falls
- muscle weakness
- joint stiffness
Duchenne muscular dystrophy symptoms appear early, usually between the ages of 3 to 5. The condition progresses quickly, affecting the legs and hips first, and leads to the need for a wheelchair by the age of 12 - 13. Symptoms include those listed above as well as fatigue, problems with the bones in the back and chest, and intellectual disability. People with this condition often develop large calves due to large fatty deposits that accumulate alongside muscle. They may eventually also have trouble breathing and develop pneumonia.
Becker's muscular dystrophy is an inherited muscular dystrophy which almost exclusively affects men. Worldwide, 1 in every 35,000 males is affected. It has a later onset than Duchenne Muscular Dystrophy, usually starting around age 12, and is much less severe and progresses more slowly. Symptoms include those listed above, plus heart disease, problems with the curvature of the spine, fatigue, problems with thinking, and breathing difficulties.
Symptoms of facioscapulohumeral muscular dystrophy (also called Landouzy-Dejerine muscular dystrophy) include weak facial and shoulder muscles and difficulty with lifting arms, whistling, and closing eyes. It affects mainly the upper body and can also cause hearing loss, speech problems, and changes in heart rhythm. Symptoms often start around ages 10 to 26, but may also start at a later stage. This disorder affects 1 in 20,000 people and is the third most common muscular dystrophy in the world.
Limb-girdle muscular dystrophies cause weakness and wasting in the arm and leg muscles. There are over 20 different sub-types of this muscular dystrophy, which affects 0.5 to 4 per 100,000 people worldwide. Symptoms usually start to appear in childhood or early adulthood. Muscle weakness starts in the pelvic area and moves to the shoulders and other body parts.
Emery-Dreifuss muscular dystrophy causes wasting of the muscles in the lower legs as well as the upper arms. It may also affect other areas such as the shoulders, chest, and face. Usually, the muscle contractures (shortening of muscle) appear before the muscle weakness appears.
Oculopharyngeal muscular dystrophy is an adult-onset dystrophy (i.e., appears after the age of 45) that primarily affects those of French Canadian and Jewish descent. In Quebec, 1 in 1000 people has this type of muscular dystrophy. Symptoms include difficulty swallowing (dysphagia), tongue weakness, weakness in the proximal muscles, difficulty looking up or double-vision (diplopia), and closing or drooping eyelids (ptosis). It also causes tongue and facial muscle weakness.
Distal muscular dystrophy usually occurs after age 35 and causes weakness in the ankles, making it difficult to walk.
Mitochondrial myopathies are caused by defects in the genes of the mitochondria, which are specialized units found inside cells that create the energy needed for cells to work. For this type of muscular dystrophy, some parents will pass the mutation to the child while others may not. Symptoms include those listed above, plus heart problems, seizures, gastrointestinal tract disorders, skeletal muscle issues, and problems with vision and hearing.
Myotonic muscular dystrophy is the most common form of adult-onset muscular dystrophy and is genetically passed from parent to child. It affects men and women equally. In general, symptoms do not appear until after the age of 20 with the exception of myotonia congenita, a congenital form of the disease (present at birth). However, in some people, such as those with proximal myotonic myopathy (another form of muscular dystrophy), symptoms may not appear until 30 to 60 years of age. This type of muscular dystrophy can also affect the heart (arrhythmias), eyes (cataracts), lungs, digestive tract, and brain function and can be associated with diabetes.