Polymorphisms in Factor II and Factor V thrombophilia genes among Circassians in Jordan

Genetic Polymorphisms of Pharmacogenomic VIP Variants in the Circassian Subpopulation from Jordan

BACKGROUND

It has been suggested that genetic variation within candidate pharmacogenes contributes to the differences in drug safety and efficacy as well as risk of adverse drug reactions among different ethnic groups. Illustrating the polymorphic distribution of Very Important Pharmacogenes (VIPs) in various ethnic groups will contribute to the development of personalized medicine for those populations.

OBJECTIVE

The present study aimed to identify the polymorphic distribution of VIPs in the Circassian subpopulation of Jordan and compare their allele frequencies with those of other populations.

METHODS

A total of 130 healthy and unrelated Circassian adults from Jordan were randomly recruited and genotyped for eleven VIP variants within the thiopurine S-methyltransferase (TPMT), ATP-binding cassette, sub-family B, member 1 (ABCB1), and vitamin D receptor (VDR) genes via Sequenom's MassARRAY® genotyping platform (iPLEX GOLD).

RESULTS

Our data on the allelic frequencies of the investigated VIP variants were compared to those of 18 other populations, comprising 11 HapMap populations, 6 Exome Aggregation Consortium populations, and the Chechen- Jordanian population from Jordan. Circassian-Jordanians were found to most resemble the African, Chechen- Jordanian, European (Finnish), European (non-Finnish), and South-Asian populations.

CONCLUSION

Circassians from Jordan significantly differ from other populations in terms of the allelic frequencies of selected VIP variants. The present findings constitute the first set of pharmacogenetic data for Circassian population from Jordan, providing a basis for safe drug administration that may be useful in diagnosing and treating diseases in this ethnic group.

Interethnic Variations of UGT1A1 and UGT1A7 Polymorphisms in the Jordanian Population

BACKGROUND

Glucuronidation is one of the most important phase II metabolic pathways. It is catalyzed by a family of UDP-glucuronosyltransferase enzymes (UGTs). UGT1A1 and UGT1A7 catalyze the glucuronidation of a diverse range of medications, environmental chemicals and endogenous compounds. Polymorphisms in the UGT1A gene could potentially be significant for the pharmacological, toxicological and physiological effects of the enzymes.

OBJECTIVE

The UGT1A gene is polymorphic among ethnic groups and the aim of this study was to investigate the different UGT1A1 and UGT1A7 polymorphisms in Circassians, Chechens and Jordanian-Arabs.

METHODS

A total of 168 healthy Jordanian-Arabs, 56 Circassians and 54 Chechens were included in this study. Genotyping of 20 different Single-nucleotide polymorphism (SNPs) was done by using polymerase chain reaction- DNA sequencing.

RESULTS

We found that Circassians and Chechens have significantly higher allele frequencies of UGT1A7*2, UGT1A7*3 and UGT1A7*4 than the Jordanian-Arab population, but all three populations have similar frequencies of UGT1A1*28. Therefore, Circassians and Chechens are expected to have significantly lower levels of the UGT1A7 enzyme with almost 90% of these populations having genes that encode low or intermediate enzyme activity.

CONCLUSION

This inter-ethnic variation in the UGT1A alleles frequencies may affect drug response and susceptibility to cancers among different subethnic groups in Jordan. Our results can also provide useful information for the Jordanian population and for future genotyping of Circassian and Chechen populations in general.

High prevalence of factor V Leiden and prothrombin G20101A mutations in Kashmiri patients with venous thromboembolism

AIM

The genetic variants of the factor V (G1691A), prothrombin (G20210A) and MTHFR (C677T) genes have been widely implicated as inherited risk factors for developing venous thrombosis. This study was undertaken to reveal the frequency of these mutations in Kashmiri patients with venous thromboembolism.

METHODOLOGY

A case-control study was designed with 250 VTE patients and 250 healthy controls. The mutations were analysed using ARMS-PCR and PCR-RFLP approach.

RESULT

The factor V Leiden G1691A mutation was found in 17/250 (6.8%) VTE patients and prothrombin G20210A mutation was found in 7/250 (2.8%) VTE patients while no mutation was found in any of the healthy controls. Both the mutations were found to be significantly associated with the increased risk of VTE (p = 0.0001 and 0.0150 respectively) while no association of VTE risk with MTHFR C677T polymorphism was found (p = 0.53).

CONCLUSION

The increased frequency of factor V Leiden G1691A and prothrombin G20210A mutation in VTE patients indicates a significant role of these mutations in the development of VTE in our population. We therefore suggest the routine screening of these two mutations as thrombophilic markers in Kashmiri patients with venous thromboembolism.

Prevalence of MTHFR C677T single nucleotide polymorphism in genetically isolated populations in Jordan

Methylenetetrahydrofolate reductase (MTHFR) C677T single nucleotide polymorphism is a major inherited risk factor of venous thromboembolism. We sought to determine its prevalence in genetically isolated populations of Chechens and Circassians in Jordan. The MTHFR C677T mutation was analyzed from blood samples taken from 120 random unrelated Chechens and 72 Circassians. The prevalence of the MTHFR mutation in the Chechen population was 27.5% (allele frequency 15%); the prevalence among the Circassians was 50% (allele frequency 29.2%). The prevalence in the Chechen population is similar to that in Jordan and other world populations, but it is higher in the Circassian population. This study will contribute to understanding the interaction between genetic and environmental risk factors underlying thrombosis and will be useful in deciding which genetic variants should be tested in a clinical genetic testing service.