Correlation analysis of UGT1A1 gene and neonatal hyperbilirubinemia based on MLPA-NGS technique

Abstract Objective: This study aims to explore whether there was a correlation between unexplained severe neonatal hyperbilirubinemia and the following six gene pathogenic variants: c.211G>A of UGT1A1 gene, c.388A>G, c.597C>T, c.521T>C of SLCO1B1 gene, c.175T>C, and c.7G>A of BLVRA gene.Methods: This was a case-control study. The hyperbilirubinemia group, including 65 neonates with unexplained severe hyperbilirubinemia (serum total bilirubin level ≥342 μmol·L-1), was hospitalized in the neonatal intensive care unit of Shanghai Children's Hospital from January 2019 to September 2020. The control group included 52 neonates with birth defects and serum total bilirubin level £221 μmol·L-1. The six gene pathogenic variants mentioned above were investigated using MLPA-NGS technique. Pathogenic variants and allele frequencies were compared between the two groups.Results: Compared with previous sequencing results, the concordance rate of c.211G>A was 98.3% (115/117), while all other pathogenic variants had a concordance rate of 100%. The pathogenic variants frequencies were as follows: c.388A>G of SLCO1B1 gene (93.84%)>c.7G>A of BLVRA gene (89.23%)> c.597C>T of SLCO1B1 gene (81.54%)> c.211G>A of UGT1A1 gene (69.23%)> c.521T>C of SLCO1B1 gene (26.15%)> c.175T>C of BLVRA gene (18.46%). A allele frequency of c.211G>A of hyperbilirubinemia group was 45.38%, while A allele frequency of control group was 21.15%. The differences were statistically significant, with c2=14.988, P<0.001. No significant difference was observed in allele frequency of other gene pathogenic variants between the two groups, with P>0.05. Binary logistic regression results revealed that c.211G>A of UGT1A1 gene was a high-risk factor for unexplained severe neonatal hyperbilirubinemia, with OR=4.233, 95% CI: 1.896-9.451. No significant difference was observed in serum total bilirubin levels between mutation types.Conclusions: c.211G>A of UGT1A1 gene was significantly correlated with unexplained severe neonatal hyperbilirubinemia and was a high-risk factor for the disease. MLPA-NGS technique was a highly accurate, rapid, and cost-effective method in identifying common and known gene loci of severe neonatal hyperbilirubinemia. It can be employed as a point mutation screening approach for detecting hyperbilirubinemia-related pathogenic variants.