and gene polymorphisms in the Croatian population.

Background: Organic anion-transporting polypeptide 1B1 (OATP1B1) and the ATP-binding cassette subfamily G member 2, ABCG2, are important transporters involved in the transport of endogenous substrates and xenobiotics, including drugs. Genetic polymorphisms of these transporters have effect on transporter activity. There is significant interethnic variability in the frequency of allele variants.

Aim: To determined allele and genotype frequencies of and genes in Croatian populations of European descent.

Subjects And Methods: A total of 905 subjects (482 women) were included. Genotyping for c.421C > A (rs2231142) and for c.521T > C (rs4149056), was performed by real-time polymerase chain reaction (PCR) using TaqMan DME Genotyping Assays.

Results: For c.421C > A, the frequency of CC, CA and AA genotypes was 81.4%, 17.8% and 0.8% respectively. The frequency of variant 421 A allele was 9.7%. For c.521T > C, the frequency of TT, TC and CC genotypes was 61.7%, 34.8% and 3.5% respectively. The frequency of variant 521 C allele was 20.9%.

Conclusion: The frequency of the ABCG2 and SLCO1B1 allelic variants and genotypes in the Croatian population is in accordance with other European populations. Pharmacogenetic analysis can serve to individualise drug therapy and minimise the risk of developing adverse drug reactions.