Faculty Opinions recommendation of Evaluating plague and smallpox as historical selective pressures for the CCR5-Delta 32 HIV-resistance allele.

The Latitude Wise Prevalence of the CCR5-Δ32-HIV Resistance Allele in IndiaThe chemokine receptor CCR5 plays a crucial role during CD4-mediated entry of HIV-1 in macrophages and a 32 bp deletion in the CCR5 gene (CCR5-Δ32) confers protection against HIV infection and AIDS progression. To evaluate the contribution of this host genetic factor in aggravating India's HIV/AIDS problem, we exclusively examined the frequency of CCR5-Δ32 in 43 different ethnic endogamous Indian populations comprising 1,882 individuals and its latitude-wise distribution in India. This is the first report of prevalence and latitude-wise distribution of CCR5-Δ32 in such large scale in India, which indicates that most of the Indian populations lack the CCR5-Δ32 mutation. This mutation was exhibited in only 13 out of the 43 ethnic populations of India studied with allelic frequency 0.62 - 5%. Southward decreasing cline was observed for frequencies of CCR5-Δ32 (0.79% to 5.0% in North vs. 0.62% to 1.4% South). These results are in accordance with HIV/AIDS prevalence in India, and suggest that absence of CCR5-Δ32 mutation may be one of the important factors for HIV/AIDS incidence in India.

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Human population structure and the adaptive response to pathogen-induced selection pressures

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2011.0305 ◽

2012 ◽

Vol 367 (1590) ◽

pp. 878-886 ◽

Cited By ~ 27

Author(s):

John Novembre ◽

Eunjung Han

Keyword(s):

Population Structure ◽

Adaptive Evolution ◽

Evolutionary Genetics ◽

Theoretical Models ◽

Pathogen Resistance ◽

Structured Populations ◽

Selection Pressures ◽

Hiv Resistance ◽

Selective Pressures ◽

Genomic Studies

The past few years of research in human evolutionary genetics have provided novel insights and questions regarding how human adaptations to recent selective pressures have taken place. Here, we review the advances most relevant to understanding human evolution in response to pathogen-induced selective pressures. Key insights come from theoretical models of adaptive evolution, particularly those that consider spatially structured populations, and from empirical population genomic studies of adaptive evolution in humans. We also review the CCR5 -Δ32 HIV resistance allele as a case study of pathogen resistance in humans. Taken together, the results make clear that the human response to pathogen-induced selection pressures depends on a complex interplay between the age of the pathogen, the genetic basis of potential resistance phenotypes, and how population structure impacts the adaptive process in humans.

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