Source:http://linkedlifedata.com/resource/umls/id/C0700595
MSH: A group of recessively inherited diseases that feature progressive muscular atrophy and hypotonia. They are classified as type I (Werdnig-Hoffman disease), type II (intermediate form), and type III (Kugelberg-Welander disease). Type I is fatal in infancy, type II has a late infantile onset and is associated with survival into the second or third decade. Type III has its onset in childhood, and is slowly progressive. (J Med Genet 1996 Apr:33(4):281-3),NCI: A group of congenital neurodegenerative disorders affecting motor neurons, resulting in muscle weakness and atrophy in childhood. Signs and symptoms include hypotonia, difficulty breathing, poor feeding, and flaccid quadriplegia.