]> 2026-07-31T12:14:20+00:00 WBR0984 0 en Pyridoxine Biotin Niacin Folic acid Thiamine Maple syrup urine disease (MSUD) is an autosomal recessive genetic disease characterized by the deficiency of alpha-keto acid dehydrogenase. Patients with MSUD often appear normal at birth. However, plasma concentrations of branched-chain amino acids (leucine, isoleucine, and valine) gradually increase, and the disease typically manifests during the 2nd or 3rd day of birth. Manifestations include irritability, poor feeding, convulsions, lethargy, opisthotonus, and a distinctive honey-like/burnt sugar urine odor. Patients may also exhibit stereotyped movements referred to as fencing or bicycling. If left untreated, patients die by the 10th day of birth from ketoacidosis and respiratory failure. The diagnosis of MSUD is confirmed by elevated urinary concentrations of branched-chain amino acid, hydroxyacid, and keto acid. In USA, newborn screening for MSUD is necessary for early treatment and prevention of complications. Management of MSUD involves thiamine supplementation (thiamine is a cofactor for alpha-keto acid dehydrogenase) and dietary restrictions, where patients are advised to avoid foods with branched-chain amino acids.<br/> '''Educational Objective:''' Maple syrup urine disease (MSUD) is an autosomal recessive genetic disease characterized by the deficiency of alpha-keto acid dehydrogenase. Management of MSUD involves thiamine supplementation (thiamine is a cofactor for alpha-keto acid dehydrogenase) and dietary restrictions, where patients are advised to avoid foods with branched-chain amino acids.<br/> '''References:''' Strauss KA, Puffenberger EG, Morton DH. Maple Syrup Urine Disease. In: Pagon RA, Adam MP, Ardinger HH, et al., editors. GeneReviews®. Seattle (WA): University of Washington, Seattle; 2006. Available from: http://www.ncbi.nlm.nih.gov/books/NBK1319/<br> First Aid 2014 page 112 Biochemistry A 1-year-old boy is evaluated for mental retardation and developmental delay. The mother states that the family returned to USA only one day ago. Abroad, the boy had been diagnosed with a genetic disease, and the family has been advised to follow a special diet to manage the child's condition. The mother cannot recall the name of the supplements and she is concerned about her child's health. Metabolic studies demonstrate acidosis and elevated concentrations of urinary leucine, isoleucine, and valine. The physician explains that the patient needs strict dietary restriction along with vitamin supplementation to improve his clinical condition. Three months later, laboratory testing demonstrates significant reduction in the urinary concentration of leucine, isoleucine, and valine. Supplementation with which of the following vitamins most likely improved this patient's condition? E General Principles 2020-10-28T02:16:54Z 2459150.5950694 WBR0984