Genetic Diversity within Chemokine Receptor 5 (CCR5) for Better Understanding of AIDS

The chemokine receptor 5 (CCR5) serves as a co-receptor for the human immunodeficiency virus-1 (HIV-1) that facilitates viral entry into cells. Individuals who are homozygous for a 32 bp deletion of the CCR5 gene are resistant to infection, while for heterozygote carriers their HIV disease progression is delayed. To understand the variable HIV-1 disease course that still exists among rare carriers of this deletion, studies have focused on polymorphisms of the CCR5 gene. Nine different CCR5 human haplotypes (HH) were defined as HHA, HHB, HHC, HHD, HHE, (HHF*1 and HHF*2), and (HHG*1 and HHG*2). Less is known about the effect of these polymorphisms during combined antiretroviral treatment (cART) as the influence of the CCR5 haplotypes on the treatment outcome was not studied extensively. We have reported four novel indels and two new polymorphisms from one ethnic adult Omani population in the 5′UTR of the CCR5 gene. Genetic diversity of the CCR5 haplotypes among acquired immunodeficiency syndrome (AIDS) patients receiving cART and healthy people is discussed. Our results demonstrated the importance of genetic diversity in the CCR5 gene and clearly indicate the importance of understanding the pattern of genetic diversity and its implications for better understanding AIDS.