adult spinal muscular atrophy UMLS_CUI:C1838230 MESH:C563948 ICD10CM:G12.1 OMIM mapping confirmed by DO. [SN]. disease_ontology A spinal muscular atrophy that is characterized by progressive muscular weakness and motor disability that typically presents in the third decade of life and has_material_basis_in mutations in the SMN1 or SMN2 genes that are required for the survival of motor neurons. ORDO:83420 OMIM:271150 DOID:0050529 SMA4 SPINAL MUSCULAR ATROPHY, ADULT FORM SPINAL MUSCULAR ATROPHY, TYPE IV spinal muscular atrophy 4 autosomal recessive disease spinal muscular atrophy