Congenital Myotonia is a rare genetic condition that affects muscle function. It is characterized by delayed relaxation of muscles after contraction, leading to stiffness and difficulty in movement. This condition is often present at birth and can vary in severity among individuals. The disorder is caused by mutations in genes responsible for muscle ion channels, particularly the CLCN1 gene. Symptoms may include muscle stiffness, especially after periods of rest, and may improve with repeated use of the muscles. Treatment focuses on managing symptoms and improving mobility through physical therapy and medications.