Q. Explain about Maple Syrup Urine Disease?

Maple Syrup Urine Disease (MSUD) is a group of inherited metabolic disorders of three branched chain amino acids (BCAA) namely leucine, isoleucine and valine. These three amino acids are normally metabolised to ketoacids and then decarboxylated lo simple acids. In MSUD disorder an oxidative decarboxylase in the white blood cells is missing. Since the carboxyl groups cannot be removed there is an accumulation of branched chain ketoacids and their amino acid precursors. The branched chain a ketoacids is relatively acute neurotoxins and probably interfere with oxygen consumption and ATP production in the medullar reticular substance of the brain. There is a progressive neurologic dysfunction and production of fragrant urine with the odour of burnt sugar or maple syrup.