Full results of the genome-wide scan which localises a locus controlling the intensity of infection by Schistosoma mansoni on chromosome 5q31-q33

Three hundred million individuals are at risk of infection by schistosomes, and thousands die each year of severe hepatic disease. Previous studies ha ve shown that the intensity of infection by Schistosoma mansoni in a Brazil ian population is controlled by a major gene, denoted as SM1. We report her e the full results of a genome-wide search that was performed on this popul ation to localise SM1. Two hundred and forty-six microsatellites were used for the primary map, and only one region in 5q31-q33 provided significant e vidence of linkage, SM1 was subsequently mapped to this region, which conta ins several genes encoding cytokines or cytokine receptors which are involv ed in protection against schistosomes. Three additional regions, 1p22.2, 7q 36 and 21q22-22-qter, yielded promising, although not significant, led-scor e values, These regions contain candidate genes encoding cytokines or molec ules relevant to anti-schistosome immunity.