CLCN1 is a gene that provides instructions for making a protein called chloride channel 1. This protein is primarily found in skeletal muscle cells and plays a crucial role in maintaining the balance of chloride ions, which are important for muscle function and electrical signaling. Mutations in the CLCN1 gene can lead to various muscle disorders, such as myotonia congenita, characterized by delayed relaxation of muscles after contraction. Understanding CLCN1 is essential for diagnosing and treating these conditions, as it helps researchers develop targeted therapies and improve patient care.