Genetic profiling of in the Slovenian population.

Determining variant alleles to predict patient response to thiopurine therapy represents one of the first successful implementations of pharmacogenomics in clinical practice. However, despite the -adjusted thiopurine dosing, some wild-type patients still exhibit toxicity at standard doses. Over the past decade, the pharmacogene has emerged as a significant co-modulator of thiopurine therapy. Initially, was considered important predominantly in Asian populations, but recent studies have highlighted its relevance in European populations as well.To evaluate the pharmacogenetic significance of in the Slovenian population, we sequenced extended regions of exon 1 and exon 3 in 109 healthy individuals and 37 patients with acute lymphoblastic leukemia.We identified eight variants, including one with established clinical significance (allele *3) and one extremely rare variant (Chr13 at 48045861; GRCh38, NC_000013.11). The frequencies of most previously described variants in both the general population and in the ALL cohort were consistent with those reported in other European populations, except for rs45465203, which was less frequent in the Slovenian population. None of the variants, except for , were associated with cumulative thiopurine doses in ALL patients. However, these variants warrant further investigation in larger ALL cohorts.