Source:http://linkedlifedata.com/resource/umls/id/C0027127
MSH: Inherited myotonic disorders with early childhood onset MYOTONIA. Muscular hypertrophy is common and myotonia may impair ambulation and other movements. It is classified as Thomsen (autosomal dominant) or Becker (autosomal recessive) generalized myotonia mainly based on the inheritance pattern. Becker type is also clinically more severe. An autosomal dominant variant with milder symptoms and later onset is known as myotonia levior. Mutations in the voltage-dependent skeletal muscle chloride channel are associated with the disorders.,NCI: A genetic congenital neuromuscular disorder affecting the skeletal muscles. It is caused by mutations in the chloride channel gene (CLCN1 gene). It is characterized by muscle stiffness, hypertrophy, pain, and cramping.