Comparison of fluorescent spot test and G-6-PD activity assay versus G-6-PD mutation analysis for detection of G-6-PD deficiency in newborns

Abstract

Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency, due to mutations in the X-linkedG-6-PD gene, is the most common enzyme defect in the world. Fluorescent spot test (FST) and G-6-PD activity assay are widely used for diagnosis of G-6-PD deficiency.  The aim of this study was to compare the effectiveness of FST and G-6-PD activity assay for detection of G-6-PD deficiency with G-6-PD mutation analysis. EDTA-blood samples of 270 neonates (130 males and 140 females) were recruited from three hospital laboratories in northeast Thailand after performing the FST.  All samples were further investigated for G-6-PD activity and G-6-PD mutation. In male neonates, FST showed 98.1% sensitivity and 94.8% specificity, and G-6-PD activity assay had 100% sensitivity and 90.9% specificity). Among females, both FST and G-6-PD activity assay showed low sensitivity as 42.9% and retained high specificity of 100% and 96.2%, respectively. This study demonstrated a comparable effectiveness of FST and G-6-PD activity assay for diagnosis of G-6-PD deficiency. However, these 2 methods exhibited low sensitivity to identify females who carry G-6-PD gene mutation. The definitive diagnosis of these females requires molecular detection of G-6-PD mutation.This data is useful for each hospital to select a G-6-PD test which is fit for the propose of investigation, budget and number of samples.