Screening for Glucose-6-Phosphate Dehydrogenase deficiency using quantitative analysis of G6PD activity: A pilot study to expand the newborn screening panel in Sri Lanka

Abstract

Introduction: Glucose-6-phosphate dehydrogenase (G6PD) deficiency affects over 400 million individuals worldwide and commonly found in Asia and in the Mediterranean region. This study was aimed to assess the feasibility of incorporating G6PD screening to the existing newborn screening panel in Sri Lanka. Methods: Dried blood spot samples (n=8795) received during a period of two months consecutively were subjected to the initial analysis and the G6PD activity was calculated by a quantitative analysis of comparing the sample to the control with a known activity using the haemoglobin normalization method. All babies with G6PD residual activity < 2.5 U/gHb were recalled (n=215) for a second sample after 6 months and analyzed using the same assay protocol in order to validate the assay Results: Analysis of second samples revealed that 58 babies (36 males and 22 females) continued to have < 2.5 Ug Hb activity. The incidence of G6PD deficiency in this selected population was 1 in 155. Range of the measured G6PD activity was 0.5 – 13.8 U/g Hb. Inter assay variation was 2.7% (13.81 U/gHb). Hambantota and Matara districts of the Southern province, which were previously known as malaria endemic areas, reported a higher prevalence. Conclusions: The incidence of G6PD deficiency is reported for the first time among neonates in Sri Lanka. However, the cut-offs we have defined at 6 months may be at a disadvantage with high attrition, but it saves the cost of additional genetic analysis.