Comparison of molecular mutations of G6PD deficiency gene between icteric and nonicteric neonates

Jaundice is a common disorder in neonates and one of the provable causes of glucose-6-phosphate dehydrogenase (G6PD) deficiency, some mutation types of which may be associated with severe neonatal icter. The present study has been conducted to compare G6PD mutations in incteric and non icteric neonates. This case-control study was implemented in the NICU and Newborn Ward of Amirkola Children Hospital in 2007-2008. Available sampling approach was used and 50 icteric as well as 50 non-icteric newborns, both with G6PD deficiency, were selected as the case and the control group respectively. G6PD deficiency was diagnosed using FST (Fluorescent Spot Test) method. All samples were first evaluated in terms of Mediterranean mutation and the negative cases were then examined for Chatham mutation; all remaining samples were finally tested for Cosenza mutation. G6PD mutations were compared in the two groups and P-value less than 0.05 was considered significant. In icteric group, 76% were male and 24% were female and in non-icteric group, 70% were male and 30% were female. The mean weight of neonates was 3.2 ± 0.4 kg and 2.8 ± 0.8 kg in icteric and non-icteric groups respectively (p<0.05). In non-icteric group, 54% Mediterranean, 18% Chatham, and 28% Cosenza negative were observed and in icteric group, 56% Mediterranean, 32% Chatham, and 12% Cosenza negative were found; the distribution of Mediterranean and Chatham mutations was not significantly different between the two groups (p>0.05), however, the distribution of rare mutations (Cosenza negative) was significantly different between icteric and non-icteric groups with enzyme deficiency (p<0.05). The mean bilirubin level was not statistically different in Mediterranean (18.5±2.9), Chatham (18.8±2.1) and Cosenza negative (20±4.3) mutations (p> 0.05). Newborns with Chatham mutation have been less in need of exchange transfusions (p <0.05) indicating that rare mutations of G6PD gene may less likely lead to neonatal icter.