Symptoms of Duchenne muscular dystrophy
Affected children are normal through the first year of life.
The first clue is that the child may walk later than expected, but detectable weakness is not present until 3 to 4 years of age.
The pelvic girdle weakens first and gives rise to the characteristic Gowers’ sign.
Soon widespread weakness is apparent, and relentless progression ensues. Most children become unable to walk by the end of their first decade.
Once the patient is wheelchair bound, flexion contractures and progressive scoliosis develop. Cardiac involvement is invariable.
Mild intellectual impairment is also common in these patients.
Death from pulmonary infection, respiratory failure, or cardiac failure usually occurs by age 30 years.