Objective: To study the distribution of mutations of UDP-glucuronosyltransferase 1A1 (UGT1A1) gene and its relationship with hyperbilirubinemia among neonates with hyperbilirubinemia of Guangxi Heiyi Zhuang nationality.

Methods: Total genomic DNA was extracted from the blood of 100 neonates with hyperbilirubinemia (case group) and 100 neonates without hyperbilirubinemia (control group), all of whom were selected from Guangxi Heiyi Zhuang population. TATA box and all exons of UGT1A1 gene were amplified by PCR and directly sequenced.

Results: (TA)7 insertion mutation in TATA box, G71R missense mutation in exon 1, and 4 single nucleotide polymorphisms (SNPs) (rs199539868, rs114982090, rs1042640 and rs8330) in exon 5 were observed. The allele frequency of G71R mutation in the case group was significantly higher than that in the control group (P<0.01). There were no significant differences in the genotype distribution and allele frequency of TATA box mutation and SNPs (rs1042640 and rs8330) between the two groups (P>0.05). The logistic regression analysis showed that the odds ratios (95% confidence intervals) of UGT1A1 TATA box mutation, G71R mutation, and SNPs (rs1042640 and rs8330) associated with the development of neonatal hyperbilirubinemia were 0.846 (0.440, 1.629), 3.932 (1.745, 8.858), 0.899 (0.364, 2.222), respectively.

Conclusions: (TA)7 insertion mutation and G71R missense mutation of UGT1A1 gene are common mutation types in neonates with hyperbilirubinemia of Guangxi Heiyi Zhuang nationality. Four SNPs (rs199539868, rs114982090, rs1042640, and rs8330) was first reported in China. UGT1A1 G71R missense mutation is a risk factor for hyperbilirubinemia in neonates of Guangxi Heiyi Zhuang nationality.