Contribution of the CCR5 and MBL genes to susceptibility to HIV type 1 infection in the Finnish population

Homozygosity for a variant of a chemokine receptor gene (CCR5) has been shown to protect from HIV-1 infection. Variants of the mannose-binding lectin (MBL) gene have been suggested to predispose to HIV-1 infection. These genetic variants and their possible role in susceptibility to HIV-1 infection were studied in sample material from more than 300 Finnish HIV-infected and control individuals. The genotyping was carried out efficiently using a novel, primer extension assay in a miniaturized oligonucleotide array format. Homozygotes for the protective deletion allele of the CCR5 gene were found only in the control group, and the frequency of the allele was high in the Finnish population. Homozygosity for the MBL, variant alleles was enriched significantly in the HIV-1-infected group, thus providing further evidence for the harmfulness of MBL variant homozygosity in HIV-1 transmission.