methylmalonic aciduria due to methylmalonyl-CoA mutase deficiency vitamin B12-unresponsive methylmalonic acidemia type mut- ICD10:E71.1 MONDO:0019267 Orphanet:79312 SCTID:237946002 UMLS:CN205894 Vitamin B12-unresponsive methylmalonic acidemia type mut- is an inborn error of metabolism characterized by recurrent ketoacidotic comas or transient vomiting, dehydration, hypotonia and intellectual deficit, which does not respond to administration of vitamin B12. partial deficiency of methylmalonyl-CoA mutase vitamin B12-unresponsive methylmalonic aciduria type mut-