Frequencies of two functionally significant SNPs and their haplotypes of organic anion transporting polypeptide 1B1 SLCO1B1 gene in six ethnic groups of Pakistani population

Objective(s):Organic anion transporter polypeptide 1B1 (OATP1B1) encoded by solute carrier organic transporter 1B1 (SLCO1B1) gene; a transporter involved in the uptake of drugs and endogenous compounds is present in hepatocyte sinusoidal membrane. Aim of this study was to investigate the frequencies of functionally significant SNPs (388A>G and 521T>C) and their haplotypes in 6 ethnic groups of Pakistani population through the development of rapid and efficient Tetra amplification refractory mutation system (T. ARMS) genotyping assay. Materials and Methods: Frequencies of alleles, genotype, and haplotypes of two functionally significant Single nucleotide polymorphism in 180 healthy Pakistani subjects and distributions in six ethnic groups by using a single step T. ARMS genotyping assay. Results: The allelic frequency for 388A>G SNP was 50 in total Pakistani population with distributions of 9.7, 15.1, 19.4, 16.1, 18.3, and 21.5 in Punjabi, Sindhi, Balouchi, Pathan, Kashmiri and Hazara/Baltistan groups respectively; and for 521T>C SNP it was 23.9 in total Pakistani population with distributions of 11.1, 8.9, 15.6, 11.1, 31.1 and 22.2 in Punjabi, Sindhi, Balouchi, Pathan, Kashmiri, and Hazara/Baltistan groups. Both functionally significant SNPs occurred in four major haplotypes with a frequency of 35.5 for 388A/521T (*1A), 40.5 for 388G/521T (*1B), 14.4 for 388A/521C (*5), and 9.4 for 388G/521C (*15) with varying distributions among six ethnic groups. Conclusion: The 388A>G and 521T>C genotypes and corresponding haplotypes are present at varying frequencies in various ethnic groups of Pakistani population. Pharmacokinetic and pharmacodynamic