OroticaciduriaFromWikipedia,thefreeencyclopediaJumptonavigationJumptosearchMedicalconditionOroticaciduriaOthernamesOrotidylicpyrophosphorylaseandorotidylicdecarboxylasedeficiency;Uridinemonophosphatesynthase(UMPS)deficiency[1]StructureoforoticacidSpecialtyHematology SymptomsMegaloblasticanemia;developmentaldelaysCausesAutosomalrecessivemutationoftheUMPSgeneDifferentialdiagnosisMitochondrialdisorders;Lysinuricproteinintolerance;liverdisease[1]TreatmentUridinetriacetateOroticaciduria(AKAhereditaryoroticaciduria)isadiseasecausedbyanenzymedeficiencyresultinginadecreasedabilitytosynthesizepyrimidines.Itistheonlyknownenzymedeficiencyofthedenovopyrimidinesynthesispathway.[2]OroticaciduriaischaracterizedbyexcessiveexcretionoforoticacidinurinebecauseoftheinabilitytoconvertoroticacidtoUMP.[3][1]Itcausesmegaloblasticanemiaandmaybeassociatedwithmentalandphysicaldevelopmentaldelays.Contents1Signsandsymptoms2Causeandgenetics3Diagnosis4Treatment5References6ExternallinksSignsandsymptoms[edit]Patientstypicallypresentwithexcessiveoroticacidintheurine,failuretothrive,developmentaldelay,andmegaloblasticanemiawhichcannotbecuredbyadministrationofvitaminB12orfolicacid.[3][2]Causeandgenetics[edit]Oroticaciduriahasanautosomalrecessivemodeofinheritance.ThisautosomalrecessivedisorderiscausedbyadeficiencyintheenzymeUMPS,[4]abifunctionalproteinthatincludestheenzymeactivitiesofOPRTandODC.[5]Inonestudyofthreepatients,UMPSactivityrangedfrom2-7%ofnormallevels.[2]Twotypesoforoticaciduriahavebeenreported.TypeIhasaseveredeficiencyofbothactivitiesofUMPsynthase.InTypeIIoroticaciduria,theODCactivityisdeficientwhileOPRTactivityiselevated.Asof1988,onlyonecaseoftypeIIoroticaciduriahadeverbeenreported.[2]Oroticaciduriaisassociatedwithmegaloblasticanemiaduetodecreasedpyrimidinesynthesis,whichleadstodecreasednucleotide-lipidcofactorsneededforerythrocytemembranesynthesisinthebonemarrow.[6]Diagnosis[edit]Elevatedurinaryoroticacidlevelscanalsoarisesecondarytoblockageoftheureacycle,particularlyinornithinetranscarb