A previous study found an inverse relationship between the carriage of the GM5,6,13,14 (expressed on IgG3);1,17(expressed on IgG1) phenotype and uncomplicated malaria in children [21], and results from another study indicated that the critical element in differences in susceptibility to malaria infection seen between two sympatric tribes in eastern Sudan might be GM6-carrying haplotypes [22]. This evidence concerns the gene IGHG3 and malaria.