Heterogeneity of glucose-6-phosphate dehydrogenase enzymopathies in the GDR.

G6PD variants of 13 patients from 12 German families with different clinical symptoms have been characterized kinetically. Vmax G6PD was nearly zero in red blood cells of all carriers. Therefore G6PD variants were isolated from leucocytes, which proved to be a suitable source for analysis of instable G6PD variants. The testing program included KmG6P, KmNADP, Ki values of NADPH, ATP and 2,3 P2G, rate of utilization of dG6P, Gal6P, dNADP, NAD, and pH dependence. From the results obtained one can conclude that all analyzed G6PD variants represent individual mutations. The degree of metabolic dysregulation can be explained by the different kinetic and physico-chemical properties of these G6PD variants.