Background: Differences in individual responses to the same medications remarkably differ among
populations. A number of genes that play integral roles in drug responses have been designated as very important
pharmacogenes (VIP), as they are responsible for differences in drug safety, efficacy, and adverse drug reactions
among certain ethnic groups. Identifying the polymorphic distribution of VIP in a range of ethnic groups will be
conducive to population-based personalized medicine.
Objective: The aim of the current study is to identify the polymorphic distribution of VIP regarding the Chechen
minority group from Jordan and compare their allele frequencies with other populations.
Methods: A total of 131 unrelated Chechen individuals from Jordan were randomly recruited for blood collection.
Identification of allelic and genotypic frequencies of eleven VIP variants within the genes of interest (ABCB1, VDR
and TPMT) was carried out by means of the MassARRAY®System (iPLEX GOLD).
Results: Within ABCB1, we found that the minor allele frequencies of the rs1128503 (A: 0.43), rs2032582 (A: 0.43),
rs1045642 (A: 0.43). For VDR, the minor allele frequencies of rs11568820 (T: 0.18), rs1540339 (T: 0.30), rs1544410
(T: 0.41), rs2228570 (T: 0.24), rs3782905 (C: 0.28) and rs7975232 (C: 0.45). Finally, the minor allele frequencies for
the TPMT rs1142345 and rs1800460 polymorphisms were found to be (C: 0.02) and (T: 0.01), respectively.
Conclusion: Significant differences in allelic frequencies of eleven ABCB1, VDR and TPMT VIP variants were
found between Jordanian Chechens and other populations. In our study, most populations that are similar to
Chechens are those from South Asian, European (Finnish) and European, including: Utah residents with Northern
and Western European ancestry, Toscani in Italia, Mexican ancestry in Los Angeles and Circassian from Jordan. The
level of similarity between Chechens and those populations means that they might have shared high levels of gene
flow in the past. The results obtained in this study will contribute to the worldwide pharmacogenomic databases and
provide valuable information for future studies and better individualized treatments.