<P> MSUD is a metabolic disorder caused by a deficiency of the branched - chain alpha - keto acid dehydrogenase complex (BCKDC), leading to a buildup of the branched - chain amino acids (leucine, isoleucine, and valine) and their toxic by - products (ketoacids) in the blood and urine . The enzyme complex consists of four subunits designated E α, E β, E, and E. The E subunit is also a component of pyruvate dehydrogenase complex and oxoglutarate dehydrogenase complex . MSUD can result from mutations in any of the genes that code for the enzyme subunits . </P> <P> Prior to the easy availability of plasma amino acid measurement, diagnosis was commonly made based on suggestive symptoms and odor . Affected individuals are now often identified with characteristic elevations on plasma amino acids which do not have the characteristic odor . The compound responsible for the odor is sotolon (sometimes spelled sotolone). </P> <P> Maple syrup urine disease can be classified by its pattern of signs and symptoms, or by its genetic cause . The most common and severe form of this disease is the classic type, which appears soon after birth, and as long as it remains untreated, gives rise to progressive and unremitting symptoms . Variant forms of the disorder may become apparent only later in infancy or childhood, with typically less severe symptoms that may only appear during times of fasting, stress or illness, but still involve mental and physical problems if left untreated . </P> <P> There are several variations of the disease: </P>

Why do i always smell like maple syrup