Congenital myotonia

Congenital myotonia is a hereditary skeletal muscle ion channelopathy caused by genetic mutations, commonly characterized by muscle stiffness and hypertrophy in the limbs. Clinically, it presents as the inability of striated muscles to relax promptly after voluntary contraction, remaining in a state of sustained contraction for a period. The disease can be divided into Thomsen's disease (autosomal dominant inheritance) and Becker's disease (autosomal recessive inheritance), which differ in their inheritance patterns and clinical features.