Duchenne muscular dystrophy (DMD) is a genetic disorder that results in muscle weakness and wasting. It is caused by a mutation in the gene that codes for dystrophin, a protein that is important for muscle function. DMD is typically diagnosed in males in early childhood, usually between the ages of 3 and 5 years. The clinical features of DMD can vary depending on the age of the individual.

In infants and young children with DMD, the most noticeable symptoms are likely to be weakness and delays in reaching developmental milestones such as sitting, standing, and walking. Children with DMD may also experience muscle contractures (permanent shortening of a muscle or joint), respiratory problems, and delays in cognitive development.

As children with DMD get older, muscle weakness and wasting tend to become more pronounced. This can lead to difficulty with mobility and an increased risk of falls and fractures. Cardiomyopathy (a condition in which the heart muscle becomes weakened or damaged) is also a common complication in children with DMD.

Adolescents and young adults with DMD may experience respiratory problems and difficulty with mobility as a result of the progressive muscle weakness and wasting. They may also have scoliosis (curvature of the spine) and require the use of assistive devices such as wheelchairs.

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