Maple Syrup Urine Disease Summary
Huong Trinh
Maple syrup urine disease
Summary
Maple syrup urine disease (MSUD) is an inborn error of metabolism which is caused by the branched-chain amino acid metabolism disorder. This disease happens when the body is unable to process certain protein blocks (amino acids) properly, then accumulate abnormally in the cells and fluids of the body, usually associated with newborn babies. Notably, the urine of patients often has a strong maple syrup odor. MSUD patients have inherited one flawed gene for MSUD from each parent. Both parents must carry a mutation of the gene associated with MSUD to pass the disease on to their child but they typically do not show signs and symptoms of the condition. There are five forms of MSUD including …show more content…
Without the BCKD enzyme, those amino acids will be accumulated abnormally throughout the body and build up to toxic levels. Joe Dancis and associates identified the metabolic block in MSUD when they observe the presence of keto acids in the patient’s urine provided. From one seminal experiment, they realized that the metabolic block in MSUD happens at the decarboxylation of BCKA and not in the transamination of BCAA. The initial step of BCAA catabolism is the transamination of leucine, iodine, isoleucine, and valine is catalyzed by a single branched-chain aminotransferase existing as both cytosol and mitochondrial isoforms to create their alpha-keto acids(KIC), alpha-keto- beta methyl valeric acid(KMV) and alpha-ket oo isovaleric acid(KIV). The next step is oxidative decarboxylation of the BCKAs catalyzed by an also single enzyme complex, i.e., the mitochondrial branched- chain alpha-ketoacid dehydrogenase complex (BCKDC). The metabolic block happens in this reaction. Through further enzymatic reaction, the end products are acetoacetate, succinyl- CoA and.
Maple syrup urine disease
Summary
Maple syrup urine disease (MSUD) is an inborn error of metabolism which is caused by the branched-chain amino acid metabolism disorder. This disease happens when the body is unable to process certain protein blocks (amino acids) properly, then accumulate abnormally in the cells and fluids of the body, usually associated with newborn babies. Notably, the urine of patients often has a strong maple syrup odor. MSUD patients have inherited one flawed gene for MSUD from each parent. Both parents must carry a mutation of the gene associated with MSUD to pass the disease on to their child but they typically do not show signs and symptoms of the condition. There are five forms of MSUD including …show more content…
Without the BCKD enzyme, those amino acids will be accumulated abnormally throughout the body and build up to toxic levels. Joe Dancis and associates identified the metabolic block in MSUD when they observe the presence of keto acids in the patient’s urine provided. From one seminal experiment, they realized that the metabolic block in MSUD happens at the decarboxylation of BCKA and not in the transamination of BCAA. The initial step of BCAA catabolism is the transamination of leucine, iodine, isoleucine, and valine is catalyzed by a single branched-chain aminotransferase existing as both cytosol and mitochondrial isoforms to create their alpha-keto acids(KIC), alpha-keto- beta methyl valeric acid(KMV) and alpha-ket oo isovaleric acid(KIV). The next step is oxidative decarboxylation of the BCKAs catalyzed by an also single enzyme complex, i.e., the mitochondrial branched- chain alpha-ketoacid dehydrogenase complex (BCKDC). The metabolic block happens in this reaction. Through further enzymatic reaction, the end products are acetoacetate, succinyl- CoA and.