Treatment of Maple Syrup Disease

Abstract

In the course of further investigations on the excretory products in maple syrup disease the strong likelihood has arisen that the defect is more extensive than is indicated in my previous article (Pediatrics, 23:348, 1959). Initially, the presence of high urinary levels of alpha-ketoisocaproic acid together with the excretion of the keto analogues of valine and isoleucine suggested an abnormality in the metabolism of branched-chain amino acids. This postulate, however, does not explain the excretion of a cyclic ester of alpha-hydroxybutyric acid, which, as first suggested by A. J. Smith and L. B. Strang (Arch. Dis. Childhood, 33:109, 1958), is responsible for the maple syrup odor. This compound could well arise as a degradation product of methionine, of which the urinary excretion is also high (Brit. M. J., 1:91, 1959), by way of alpha-ketobutyric acid.