African origins and chronic kidney disease susceptibility in the human immunodeficiency virus era

Figure 1 Historical timeline reflecting the discovery of genetic association to chronic kidney disease in populations with African ancestry. ¹Adapted from Kopp et al[³¹] and Kao et al[³⁰]; ²Adapted from Freedman et al[⁴⁹], Genovese et al[¹³], Tzur et al[²⁹]; ³Adapted from Genovese et al[⁸⁴]; ⁴Adapted from Kasembeli et al (2014 unpublished observations); ⁵Adapted from Freedman et al[⁶⁴]; ⁶Adapted from UNAIDS report on global AIDS epidemic[¹⁸]; ⁷Adapted from USRDS 2012 Annual Data Report. APOL1: Apolipoprotein L1; MYH9: Non-muscle myosin heavy chain 9; ART: Antiretroviral therapy; CKD: Chronic kidney disease.

Figure 2 Distribution of Human African Trypanosomiasis (T. b gambiense and T.b rhodesiense), MYH9 E1 and APOL1 G1 and G2 risk alleles in Africa[^12,42]. The frequency of distribution of APOL1 risk variants in Africa are represented by bar charts and overlap the areas distribution of Human African Trypanosomiasis. The numbers reflect the reported cases of Trypanosomiasis from the WHO, 2010. T.b: Trypanosoma brucei.

Figure 3 Gene-Gene, Gene-Environment steering contribution to APOL1 associated CKD and the positive selection of APOL1 associated CKD variants as a result of Trypanosomiasis. SRA: Serum resistant associated protein; HIV: Human immunodeficiency virus; T.b: Trypanosoma brucei; APOL1: Apolipoprotein L1; MYH9: Non-muscle myosin heavy chain 9; HIVAN: Human immunodeficiency virus-associated nephropathy; FSGS: Focal segmental glomerulosclerosis; T2DM: Type 2 diabetes mellitus; ESRD: End stage renal disease; CKD: Chronic kidney disease.