The symptoms of DMD (Duchenne Muscular Dystrophy) manifest as muscle weakness, gait disturbances, and loss of muscle mass. These symptoms typically begin in infancy or early childhood and show a progressive course over time. Specifically, an inability to balance or walk by 18 months of age is considered one of the early signs of the disease.

Common symptoms of DMD may include:
* Muscle weakness and atrophy (loss of muscle mass) starting in the children's legs and pelvis
* Calf muscle hypertrophy (increase in muscle size)
* Difficulty climbing stairs
* Walking difficulties that worsen over time
* Frequent falls
* Learning difficulties
* Waddling gait
* Toe walking
* General fatigue and quick exhaustion
* Difficulty getting up from a sitting position
* Reduced ability to run and jump
* Muscle pain and stiffness in muscles
* Delayed speech and language development