Phase 1 of the 1000 Genomes (1KG) Project was used to obtain genotypic data. Specifically, we downloaded Variant Call Format files relevant to each GWAS-relevant or interacting gene. The 1KG Phase 1 consisted of 1092 individuals from 14 human populations. According to the 1KG project definition, they can be classified into four continental ancestry groups, as follows. The African group included: African ancestry in Southwest USA (ASW), Luhya in Webuye, Kenya (LWK) and Yoruba in Ibadan, Nigeria (YRI); the American group included: Colombian in Medellin, Colombia (CLM), Mexican ancestry in Los Angeles, CA (MXL) and Puerto Rican in Puerto Rico (PUR); the Asian group included: Han Chinese in Beijing, China (CHB), Han Chinese South (CHS) and Japanese in Tokyo, Japan (JPT); the European group included: Utah residents with northern and western European ancestry (CEU), Finnish from Finland (FIN), British from England and Scotland (GBR), Iberian populations in Spain (IBS) and Toscani in Italy (TSI). Since 1KG American populations reflect an admixture of Amerindian, African and European ancestries [29], we refer to them in the text as ‘admixed Americans’.
