The purpose of this study was to explore the relationship between neonatal hyperbilirubinemia and G6PD deficiency and to investigate the effect of G6PD deficiency and UGT1A1 variant on bilirubin level of icteric neonates in Chaozhou, eastern Guangdong Province. The gene discussed is G6PD; the disease is hyperinsulinemic hypoglycemia, familial, 4.