Relationship among glucose-6-phosphate dehydrogenase (G-6-PD) activity, G-6-PD variants and reticulocytosis in neonates of northeast Thailand.

Abstract Background Misdiagnosis of G-6-PD deficiency in neonates, at risk of severe hemolytic episodes, extreme hyperbilirubinemia, and bilirubin encephalopathy, could possibly occur due to presence of reticulocytes, which contain higher amounts of G-6-PD than mature erythrocytes. G-6-PD mutations in the population might also affect G-6-PD activity. This study evaluated the relationship among G-6-PD activity, G-6-PD variants and reticulocytosis in northeastern Thai neonates. Methods Blood samples obtained from routine fluorescence spot test examination for G-6-PD deficiency were analyzed using a quantitative enzymatic assay and for common G-6-PD mutations by restriction fragment length polymorphism (RFLP)-PCR. Correlation between G-6-PD activity and percent reticulocytosis was determined. Results Among 106 G-6-PD-deficient (G-6PD activity  r  = 0.125, p -value = 0.201), but there is a weak correlation in G-6-PD-normal neonates ( r  = 0.377, p -value = 0.014). There is a high frequency of G-6-PD Viangchan in male hemizygous and female heterozygous G-6-PD-deficient and G-6-PD-normal neonates. Conclusions A high reticulocytosis does not bias measurements of enzyme activity in G-6-PD-deficient neonates. Also, G-6-PD activity varies among female heterozygous neonates, and G-6-PD mutation analysis provides a reliable method to detect G-6-PD deficiency.