<prompt> Branched chain ketoacid decarboxylation is defective in:Maple syrup urine diseaseHartnup diseaseAlkaptonuriaGMI gangliosidosis  <response>: Ans. A. Maple Syrup urine diseaseRef: Harper 30e page 276-278Maple Syrup Urine DiseaseBiochemical DefectDeficiency of the enzyme Branched Chain Ketoacid Dehydrogenase.Defective reaction is Defective Decarboxylation.Clinical FeaturesMental RetardationConvulsionAcidosis, ComaSmell of Burnt Sugar Tests for MSUDDiNitro Phenyl Hydrazine Test DNPH TestRotheras TestEnzyme AnalysisTreatmentRestrict Branched Chain Amino AcidGive high doses Thiamine. 