Biochemical and cytochemical evaluation of heterozygote individuals with glucose-6-phosphate dehydrogenase deficiency

The aim of this study was to diagnose heterozygous glucose-6-phosphate dehydrogenase (G6PD) deficient females by an inexpensive cytochemical G6PD staining method that is easy to perform, allowing diagnosis of G6PD deficiency without cumbersome genetic analysis. Three subject groups were included in the study. The first group consisted of 15 hemizygous deficient males. The second and the third group were composed of 15 heterozygous deficient females and 15 healthy individuals, respectively. Biochemical determination and cytochemical staining of G6PD activity were performed in samples of all subjects. Results obtained with the cytochemical staining method correlated significantly with the biochemical data (p<0.001), but a only 51-68% of the erythrocytes were stained positively in females with normal biochemical G6PD activity despite their having a G6PD-deficient child. This observation clearly indicates that these individuals are heterozygously deficient. These findings show that the cytochemical staining method to detect G6PD activity in erythrocytes is reliable, sensitive and specific and is superior to the biochemical method. Therefore, this method can be used routinely to detect heterozygous G6PD deficiency.