In Maple syrup urine disease, the amino acids excreted in urine are all EXCEPT:

- Maple syrup urine disease is a defect in the catabolism of branched chain amino acids i.e. Valine, Leucine and Isoleucine. As a result these amino acids are excreted in urine. - This defect occurs due to the inherited deficiency of branched Chain Keto-acid Decarboxylase. - So the answer is Phenylalanine Extra information: MAPLE Syrup urine disease: Autosomal Recesive Clinical Features 1. Burnt sugar like odour (because of isoleucine) 2. Ketosis, vomiting, feeding problems 3. Mental retardation (because of increased leucine) There are 4 known types of Maple Syrup Urine Disease: Type IA and IB MSUD arise from mutations in the E1a and E1b gene, which encode the enzyme a-Ketoacid decarboxylase. Type II arises from mutations in the E2 gene, which encodes Dihydrolipoyltransacylase. Type III arises from mutations in the E3 gene, which encodes Dihydrolipoamide dehydrogenase.