Human genetic susceptibility to mother to child transmission of HIV: a study of mother-infant pairs in Malawi

Mother-To-Child Transmission of HIV (HIV MTCT) is a worldwide public health problem and particularly burdens mothers and children in Sub-Saharan Africa, where in 2006, over 500,000 infants were newly infected with HIV 1. To more clearly understand the mechanisms of transmission, we studied genetic exposures and HIV MTCT in consenting mother-infant pairs receiving antenatal care in Blantyre, Malawi. We first examined infant genetic susceptibility to maternal infection through a genome wide association (GWA) scan of 655,000 SNPs. Top associations with HIV MTCT were found for 20 SNPs within 7 genes (p0.90) but not with other ancestry populations (r20.80, other ancestry r2<0.54). Frequencies of 4 SNPs in the lactase gene (LCT) varied greatly between the Malawi population and Maasai in Kenyawa, Kenya (Bonferroni p