We used the remaining 1216 GMB individuals as a validation set to model imputation into a Gambian GWAS. We imputed the GMB genotypes from a series of reference panels: all 2022 HapMap 3 (HM3) haplotypes; 200 GMB haplotypes (GMB); 200 GMB haplotypes plus 200 GHN haplotypes (GMB+GHN); and a combined set containing all 2422 GMB, GHN, and HM3 haplotypes (GMB+GHN+HM3).