Chalitpon Na nakornJariya WaisayaratCharungthai DejthevapornPornpen SrisawasdiSansanee WongwaisayawanChonlaphat SukasemFaculty of Medicine, Ramathibodi Hospital, Mahidol UniversityPrince of Songkla University2020-08-252020-08-252020-06-05Frontiers in Pharmacology. Vol.11, (2020)166398122-s2.0-85087028894https://repository.li.mahidol.ac.th/handle/123456789/58131© Copyright © 2020 Na nakorn, Waisayarat, Dejthevaporn, Srisawasdi, Wongwaisayawan and Sukasem. Aim: To investigate the variations and the frequencies of the SLCO1B1 gene in the Thai population. Methods: Collected samples were categorized into five regions of Thailand. DNA samples were genotyped for two variants, c.388A>G and c.521T>C of the SLCO1B1, using TaqMan® real-time PCR. Results: The minor allele frequencies (MAFs) of two single nucleotide polymorphisms (SNPs) were not significantly different among the five regions. The most frequent haplotype was SLCO1B1*1b (frequency: 0.654), followed by *1a (frequency: 0.217), *15 (frequency: 0.128), and *5 (frequency: 0.001). We observed a similar frequency of OATP1B1 transporter phenotypes compared to other populations. 75.85% of the Thai subjects showed normal OATP1B1 activity, 22.5% showed intermediate OATP1B1 activity, and 1.58% showed low OATP1B1 activity. Conclusion: This study reported the frequencies of the SLCO1B1 variants and the subsequent OATP1B1 activity in a large cohort of Thais that can provide important information for the guidance of personalized drug therapy.Mahidol UniversityMedicinePharmacology, Toxicology and PharmaceuticsArticleSCOPUS10.3389/fphar.2020.00728