Thomsen disease

A myotonia congenita that is characterized by muscle stiffness and an inability of the muscle to relax after voluntary contraction and that has_material_basis_in heterozygous mutation in the gene encoding skeletal muscle chloride channel-1 (CLCN1) on chromosom

A myotonia congenita that is characterized by muscle stiffness and an inability of the muscle to relax after voluntary contraction and that has_material_basis_in heterozygous mutation in the gene encoding skeletal muscle chloride channel-1 (CLCN1) on chromosome 7q34.

Signs and symptoms

• Myotonia with warm-up phenomenon
• Muscle stiffness
• Myotonia
• Skeletal muscle hypertrophy
• Handgrip myotonia
• EMG: myotonic runs
• Percussion myotonia
• Lid lag on downgaze
• Myalgia
• Muscle weakness

Also known as: Congenital myotonia, autosomal dominant form; Thomsen's disease