High frequency of the GWG (Pro Trp) envelope variant of HIV-1 in southeast Brazil

Most current HIV vaccine development research is focused on the third variable domain (V3) of the HIV-1 envelope gene product that contains the GWG amino acid sequence in the crown of the principal neutralizing determinant. Direct sequencing has detected this variant in patients in Japan France and Brazil. The present study used restriction fragment length polymorphism (RFLP) and limited DNA sequencing of the C2-V3 region of the HIV-1 envelope gene to determine the prevalence of the variant in 75 HIV-infected patients from Ribeirao Preto Brazil. According to RFLP the overall prevalence of the GWG sequence was 57% (72% in females 32% in males and 40% in newborns). Two GFG sequences and one GLG sequence were also detected suggesting that the GWG variant could be the founder sequence. The gene dendrogram indicated the samples clustered together within the subtype B of the main group.