Association Between <i>UGT1A1</i> Gene Polymorphisms and Neonatal Hyperbilirubinemia

Background: Uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) is a critical enzyme involved in bilirubin conjugation. The UGT1A1 gene, located on chromosome 2q37, encodes this enzyme. Polymorphisms within the coding region or promoter of the gene may lead to reduced enzyme activity, resulting in elevated levels of unconjugated serum bilirubin. Objectives: The present study aimed to evaluate the association between the UGT1A1 rs3755319 and rs201295078 polymorphisms and neonatal hyperbilirubinemia. Methods: This case–control study was conducted on 110 newborns with hyperbilirubinemia and 112 healthy newborns without the condition. Genomic DNA was extracted using the salting-out method. Genotyping of the rs3755319 A/C and rs201295078 (14-bp I/D) polymorphisms was performed using tetra-primer amplification refractory mutation system-polymerase chain reaction (T-ARMS-PCR) and conventional PCR, respectively. Results: The results demonstrated that the rs3755319 AA genotype, as well as the A allele, significantly increased the risk of hyperbilirubinemia compared to the CC genotype (OR = 8.23, 95% CI = 2.31 - 25.18, P < 0.001 for AA vs. CC; and OR = 1.80, 95% CI = 1.23 - 2.62, P = 0.002 for A vs. C). However, no significant association was observed between the rs201295078 (14-bp I/D) polymorphism and the risk of hyperbilirubinemia. Conclusions: In conclusion, our findings indicate a significant association between the rs3755319 variant of the UGT1A1 gene and an increased risk of neonatal hyperbilirubinemia.