Objective:To explore the UGT1A1 gene polymorphism among unconjugated hyperbilirubinemia full-term neonates in Chongqing area. Methods:The study was a reviewing trial including 330 unconjugated hyperbilirubinemia neonates. According to the jaundice etiology

the unconjugated hyperbilirubinemia babies were divided to two groups:210 with clear causes of jaundice and 120 without. Meanwhile

the severe jaundice cases were divided into two groups:213 cases undergoing exchange transfusion and 117 cases without transfusion. The UGT1A1 polymorphisms were compared between the groups. Logistic regression models were employed to an-alyze the effects of UGT1A1 polymorphisms on full-term neonatal unconjugated hyperbilirubinemia. Results:For the group of unclearcause jaundice

the total mutation incidence

homozygous mutation rate and heterozygous mutation rate of 211G>A were 49.2%

11.7%and 37.5%

respectively

significantly higher than those of 38.6%

6.2% and 32.4% in clear-cause group(P<0.001). Logistic regression indicated

the OR and 95% CI values of 211G>A mutation associated with the development of unconjugated hyperbilirubinemia and severe jaundice in full-term neonates were 1.54(3.083-8.108)and 2.64(1.278-4.508)

respectively. Conclusion:211G>A mutation of UGT1A1 maybe involved in the development of etiology unclear full-term neonatal unconjugated hyperbilirubinemia in Chongqing area.