Maple Syrup Urine Disease Essay Example | Topics and Well Written Essays - 500 words

Maple Syrup Urine Disease - Essay Example This enzyme complex is composed of three catalytic components E1, E2, and E3 and two regulatory enzymes, BCKD phosphatase and BCKD kinase. The E1 component is further divided into two subunits, E1 and E1 (Bodamer, 2008). The defect in maple syrup urine disease lies in the E1, E1, E2, and E3 components (Fauci et al, 2008: 2472). In addition, E3 component is also associated with pyruvate dehydrogenase and -ketoglutarate dehydrogenase, thus, this defect in BCKD with specific mutation in E3 causes additional deficit in pyruvate and -ketoglutarate dehydrogenases (Bodamer, 2008). The catabolism of BCAAs involves the same enzymes in the first two steps (Laygo, 2007:28). The first enzyme utilized is BCAA aminotransferase which converts leucine, isoleucine and valine to their -ketoacids: -ketoisocaproic acid, -keto--methylvaleric acid, and -ketoisovaleric acid respectively. The branched-chain -ketoacid dehydrogenase complex catalyzes the decarboxylation of these -ketoacids so that they are degraded to short fatty acids, isovaleryl-CoA, -methylbutyryl-CoA and isobutyryl-CoA (Leucine mildly to moderately elevated). Further metabolism should yield acetyl-CoA, acetoacetate, and succinyl-CoA (Bodamer, 2008). Among the clinical manifestations of maple syrup urine disease are lethargy, vomiting, encephalopathy, seizures, mental retardation, "maple syrup" odor and protein intoleranc