Organic anion transporter protein (OATP1B1) encoded by SLCO1B1 gene polymorphism (388A>G) & susceptibility in gallstone disease

Background & objectives: Organic anion transport protein 1B1 (OATP1B1) is a major transporter protein for bile salt uptake in the enterohepatic circulation of bile salts. As the role of SLCO1B1 gene (encodes OATP1B1 or liver specific transporter-1) 388 A>G polymorphism in susceptibility towards gallstone disease is unclear the prevalence of this polymorphism in healthy north Indian population was investigated. Methods: Peripheral venous blood of 270 unrelated northern Indian patients with symptomatic gallstone disease and 270 unrelated healthy control subjects was screened for SLCO1B1 gene 388 A>G polymorphism by PCR-RFLP method and genotyping was done on 12 per cent polyacrylamide gel. The cross-sectional data on accrual of cases and controls were collected and odds ratio with 95 per cent CI calculated as for case-control design. Results: Allele frequencies of 388 G were 45 per cent in gallstone cases and 44 per cent in controls with no statistical significance. Genotype frequencies in gallstone cases and controls for, genotype AA were 30 and 32 per cent; AG: 51 and 47 per cent and GG: 16 and 21 per cent respectively. No significant association of any allele or genotype with gallstone disease was found. Interpretation & conclusions: Although the prevalence of SLCO1B1 gene 388A>G polymorphism in north Indian population in high, yet this polymorphism does not appear to play a significant role in susceptibility to gallstone formation.