Age at Onset
Symptoms, Rate of Progression, and Life Expectancy
adolescence to early adulthood
Symptoms are almost identical to Duchenne but less severe; progresses more slowly than Duchenne; survival into middle age.
Symptoms include general muscle weakness and possible joint deformities; disease progresses slowly; shortened life span.
2 to 6 years
Symptoms include general muscle weakness and wasting; affects pelvis, upper arms, and upper legs; eventually involves all voluntary muscles; survival beyond 20s is rare.
40 to 60 years
Symptoms include weakness and wasting of muscles of the hands, forearms, and lower legs; progression is slow; rarely leads to total incapacity.
childhood to early teens
Symptoms include weakness and wasting of shoulder, upper arm, and shin muscles; joint deformities are common; progression is slow; sudden death may occur from cardiac problems.
childhood to early adults
Symptoms include facial muscle weakness and weakness with some wasting of shoulders and upper arms; progression is slow, with periods of rapid deterioration; life span may be many decades after onset.
late childhood to middle age
Symptoms include weakness and wasting, affecting shoulder girdle and pelvic girdle first; progression is slow; death is usually due to cardiopulmonary complications.
20 to 40 years
Symptoms include weakness of all muscle groups accompanied by delayed relaxation of muscles after contraction; affects face, feet, hands, and neck first; progression is slow, sometimes spanning 50 to 60 years.
40 to 70 years
Symptoms affect muscles of eyelids and throat causing weakening of throat muscles, which, in time, causes inability to swallow and emaciation from lack of food; progression is slow.