Interference of Haemoglobinopathies on Glucose 6 Phosphate Deficiency Testing - A Review

Abstract

Anaemia remains one of the major challenges for people in the developing world. G6PD deficiency, among other causes of anaemia, is an X-linked enzyme inherited disorder with affected individuals usually being asymptomatic but can experience varying degrees of anaemia after exposure to oxidative stressors such as infections and certain medications. G6PD deficiency affects over 500 million people globally, and it is more prevalent in malaria-endemic zones, including Sub-Saharan Africa. A significant 186 of 230 variants identified are associated with reduced e n z y m e a c t i v i t y a n d s t a b i l i t y . Haemoglobinopathies are also inherited and often result G6PD is crucial for clinical decision-making and improved patient care since affected individuals are contraindicated for certain therapeutic and dietary interventions. Brewer's technique, the fluorescent spot test, and enzyme assay are the most widely and routinely used screening methods, especially in developing countries. However, there is a paucity of data on the interference of haemoglobinopathies on these screening tools. Inheritance of haemoglobin E with other haemoglobin variants or thalassaemia has been shown to result in false full defects using Brewer's technique. More research on the effects of compensated reticulocytosis on G6PD testing, which is associated with severe anaemia due to haemoglobinopathies and other causes, need further evaluation. As new technologies and POCT evolve for the diagnosis of G6PD deficiency, it is prudent for its continuous evaluation with key consideration of variant d i s t r i b u t i o n a n d i n t e r f e r e n c e o f haemoglobinopathies.