APOL1 and kidney disorder: The overall frequency of the APOL1 risk genotype (that is, the recessive state for the diplotype: G1/G1, G1/G2 or G2/G2) varied substantially among the groups in which it was present (Fig. 4d and Supplementary Table 21), suggesting that the risk of APOL1-associated nephropathy is appreciably high across the continent, with the highest burden in west Africa.