Congenital Leucine-Sensitive Hypoglycemia

Abstract
The propensity ofl-leucine to produce a marked fall in blood glucose level in certain cases of hypoglycemia was discovered by Cochrane, Payne, Simpkiss and Woolf in 1956.1The clinical picture, the incidence, the nature of the response to casein, gelatin,l-leucine, and various other aminoacids and ketoacids, have been studied by several groups. The relevant papers have been reviewed by Cochrane,2,3and by DiGeorge and Auerbach.4 Immediate elucidation of the pathogenesis of the hypoglycemic response tol-leucine was not feasible, because methods for measurement of plasma insulin levels lacked sufficient specificity and sensitivity to permit solution of this problem. The development by Yalow and Berson5of an exquisitely sensitive highly specific immunoassay for the measurement of plasma insulin levels in man was immediately followed by an investigation of insulin levels in congenital leucine sensitive hypoglycemia. Yalow and Berson5found that the