G6PD/PK ratio: a reliable parameter to identify glucose-6-phosphate dehydrogenase deficiency associated with microcytic anemia in heterozygous subjects

To determine if measuring the ratio of glucose-6-phosphate dehydrogenase (G6PD) to pyruvate kinase (PK) is more reliable than only measuring G6PD activity to identify heterozygous G6PD− individuals with associated microcytic anemia in the Calabrian population, which shows high frequencies of both the thalassaemia (thal) trait and G6PD deficiency. Design and methods Measurement of G6PD and PK activities was carried out on 205 samples of whole blood from Calabrian subjects of both sexes (age range 10–50 years) using a double starter differential pH-metry technique. Results The G6PD/PK ratio is able to differentiate G6PD− heterozygous individuals from the normal population. G6PD/PK values also allowed us to easily identify the G6PD− heterozygous subjects with microcytic anaemia. Studentʹs t test shows that G6PD/PK ratio is more reliable in both sample groups, relative to G6PD activity in normal subjects. Conclusions G6PD/PK ratio is a reliable diagnostic parameter for mass screening for G6PD deficiency.