α-aminoadipic semialdehyde synthase

α-ami·no·adip·ic semi·al·de·hyde syn·thase (ə-me″no-ə-dipґik sem″e-alґdə-hīd sinґthās) a bifunctional enzyme comprising the two enzyme activities lysine-ketoglutarate reductase (q.v.) and saccharopine dehydrogenase (q.v.) and catalyzing the first two steps in the major pathway of lysine degradation. Deficiency of the enzyme, an autosomal recessive trait, causes hyperlysinemia or its variant saccharopinuria.