Variants of organic anion transporter polypeptide 2 gene are not risk factors associated with severe neonatal hyperbilirubinemia

Objectives: This study aimed to determine the prevalence of four variants of organic anion transporter polypeptide 2 (OATP2) gene, and their association with severe hyperbilirubinemia. Design: Observational study. Setting: A tertiary university unit. Patients: Term infants of Chinese descent. Methods: 175 infants, consisting of 65 admitted for treatment of severe hyperbilirubinemia (with serum bilirubin levels > 250 mmol/L at age 1-2 days or > 300 ?mol/L at age ? 3 days) and 110 randomly selected inborn infants without severe hyperbilirubinemia during their first month of life, were recruited. Their blood samples were subjected to sequencing analysis of exon 4 and exon 5 of OATP2 gene for detection of c.388A>G, c.521T>C, c.571T>C and c.597C>T variants. Results: The c.388A>G variant was the most common, and the c.521 T>C was least common, being present in 90.9% and 26.9% of the infants, respectively. Forward logistic regression analysis showed that the only significant risk factors associated with severe hyperbilirubinemia among these Chinese infants were: exclusive breast feeding (adjusted odds ratio (OR) = 12.5, 95% C.I.: 2.9,53.4p=0.001), infants with homozygous 211 variant of the UDPG 1A1 gene (adjusted OR = 37.7,95% C.I.: 4.4, 324.1p=0.001), and G6PD enzyme level <8.5 IU/g Hb (adjusted OR = 7.3, 95% C.I.: 3.1, 17.5p