Frequency of the CCR5 gene 32-basepair deletion in Hispanic Mexicans

A 32-basepair deletion polymorphism in the CCR5 chemokine receptor gene (DeltaCCR5) has recently been identified and shown to have functional significance in determining susceptibility to infection by human immunodeficiency virus type 1 (HIV-1) and a possible influence on disease progression in HIV-1-positive individuals. Interest has also focused on the geographical distribution of the DeltaCCR5 allele, particularly in considering epidemiological aspects of HIV disease and its impact on health economics. In this report we have assessed the frequency of the DeltaCCR5 allele in a Hispanic Mexican population and found a gene frequency of 4.4% in 103 individuals. The DeltaCCR5 allele is not present in indigenous Mexican populations but is present in about 8% of the population in Spain. Gene flow from the European gene pool consistent with Mexico's colonial past would account for the findings in this study.