Maple Syrup Urine Disease in Negro Infant

Abstract

Since 1954, fourteen infants have been described as having an inborn error of metabolism manifested by signs of central nervous system (CNS) derangement in association with either maple-syrup-scented urine or demonstrable elevations of branched-chain amino acids (or their α-keto acids) in urine, blood, or spinal fluid (Table 1). Six additional infants have been mentioned, but the information recorded is too meager to allow tabulation.^17,20,21 Utilizing material from Cases V, VII, and VIII, several studies^2,6,10,12,15of the metabolic block in these infants demonstrated an incapacity of tissue homogenates and white blood cells to carry metabolism of the branched-chain amino acids¹⁰beyond the formation of the corresponding α-keto acids *: Within this concept, partial enzymatic deficit at (b) might be expected to result only in an α-keto acid elevation. A more severe degree of block would produce a greater accumulation of branched-chain α-keto acids resulting in Reaction (a) proceeding to