Genotype and Haplotype Analysis of ABCB1 at 1236, 2677 and 3435 among Jordanian Population

Purpose: To determine the frequencies of important allelic variants and their haplotype frequencies of the gene among Jordanian population and to compare findings with those reported for other ethnic groups.Methods: Genotyping of ABCB1 (C1236T, G2677T/A and C3435T) was carried out on unrelated healthy Jordanian subjects. Different allelic variants were determined using polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP). The haplotype frequencies of these three SNPs were analyzed and compared them with those of other reported populations. Haplotype frequencies were calculated using Golden Helix Tree software and Linkage disequilibrium was represented by D”.Results: ABCB1 C3435T allele frequencies for C allele and T allele were 0.57 and 0.43, respectively. For ABCB1 G2677T/A the allele frequencies for G allele, T allele, and A allele were 0.65, 0.32 and 0.0, respectively. As for ABCB C1236T, its allele frequencies were 0.65 for C allele and 0.35 for T allele. C1236T, G2677T/A, and C3435T SNPs were expected to be structured in 8 different haplotypes with GC- C (37.6.0 %), T-T-T (18.6 %), G-C-T (14.3 %) and T-T-C (12 %) that were most prominent. The haplotype frequency distribution of our study group was found to be significantly different from those of Chinese, Indian, Japanese, African and Caucasian (p < 0.0001) and resemble Ashkenazi Jewish and Slovenian populations (p > 0.05).Conclusion: In addition to earlier studies, the findings of the current study provide evidence that suggest the use of genetic polymorphisms of ABCB1 SNPs as markers for ethnicity and ancestral origin. The analysis of haplotype and genotype can be useful in identifying the relation between ABCB1 polymorphism, disease susceptibility and drug disposition.Keywords: Genotype, Allele, MDR1, ABCB1, Polymorphism, Haplotype frequencies