[Genetic factors in the occurrence of neonatal unconjugated hyperbilirubinemia].

Objective: To study association of uridine-diphosphate-glucuronosyltransferase1A1 (UGT1A1) Gly71Arg, UGT1A1 promoter TATA-box and glucose-6-phosphate dehydrogenase (G6PD) gene mutations with the occurrence of neonatal unconjugated hyperbilirubinemia.
Methods: The TATA-box, exon 1 and exon 5 of the UGT1A1 gene and the exon 12 of G6PD gene were amplified by PCR. The products of PCR were analyzed by direct DNA sequencing. Clones for the mutations of the UGT1A1 gene and the G6PD gene were constructed in order to identify the results of the products of PCR. Seventy-two neonates with unconjugated hyperbilirubinemia (case group) and 65 healthy neonates (control group) were enrolled. The genotypes and allele frequencies of the polymorphisms of UGT1A1 Gly71Arg and UGT1A1 TATA-box were compared between the two groups. The effects of UGT1A1 Gly71Arg, UGT1A1 promoter TATA-box and G6PD gene mutations on the development of neonatal unconjugated hyperbilirubinemia were estimated using logistic regression models.
Results: There were significant differences in the genotype distribution of Gly71Arg polymorphism of UGT1A1 gene between the case and control groups (P<0.01). The Arg allele frequency of the polymorphisms of UGT1A1 gene in the case group was significantly higher than in the control group (P<0.01). There were no significant differences in the genotype distribution of the UGT1A1 promoter TATA-box between the two groups (P>0.05). The OR and 95%CI values of UGT1A1 Gly71Arg, UGT1A1 TATA-box and G6PD gene mutations associated with the development of neonatal unconjugated hyperbilirubinemia were 5.468 (2.274, 12.818), 0.688 (0.266, 1.778) and 5.081 (1.070, 24.133) respectively.
Conclusions: UGT1A1 Gly71Arg and G6PD gene mutations may be involved in the development of neonatal unconjugated hyperbilirubinemia.