Which condition is characterized by muscle weakness, myotonia, testicular atrophy, and baldness?

The condition characterized by muscle weakness, myotonia, testicular atrophy, and baldness is myotonic congenital myopathy. This genetic disorder is primarily associated with a defect in the muscle membrane, leading to characteristic muscle symptoms.

Myotonia refers to a delay in muscle relaxation after contraction, which is a classic feature seen in this condition. Muscle weakness is also a significant symptom, as the affected individuals often exhibit reduced muscular strength. Testicular atrophy and baldness are additional notable systemic manifestations that help differentiate this condition from others that might present with muscle weakness alone.

In contrast, myasthenia gravis is primarily an autoimmune disorder affecting the neuromuscular junction, leading to fluctuating muscle weakness but typically does not present with myotonia or the other systemic features mentioned. Muscular dystrophy refers to a group of inherited muscle diseases that cause progressive muscle weakness and degeneration, but it does not typically present with myotonia or the other specific systemic manifestations outlined. Spinal muscular atrophy involves degeneration of motor neurons leading to muscle weakness but lacks the myotonic aspect, testicular atrophy, and baldness seen in myotonic congenital myopathy.

Thus, the specific combination of muscle weakness, myotonia,