Parallel occurrence of oxidant-sensitivity and decreased inhibition by NADPH in G-6-PD Lublin and G-6-PD Poxnań.

In two studied variants of G-6-PD without chronic hemolysis in probands, sensitivity of enzymes to inhibition by NADPH was decreased. Ki for NADPH was 28 micronM in Gd Lublin and 19 micronM in Gd Poznań. Susceptibility to the oxidant-induced hemolysis was described in probands, as well as in patients hemizygous for two other variants of G-6-PD with increased Ki for NADPH. It is suggested that in these cases, the oxidant-induced hemolysis is aggravated by their inability to counteract the drop in NADPH concentration with an increase in G-6-PD activity.