African ancestry-specific alleles and kidney disease risk in hispanics/latinos

African ancestry alleles may contribute to CKD among Hispanics/Latinos, but whether associations differ by Hispanic/Latino background remains unknown. We examined the association of CKD measures with African ancestry-specific APOL1 alleles that were directly genotyped and sickle cell trait (hemoglobin subunit b gene [HBB] variant) on the basis of imputation in 12,226 adultHispanics/Latinos grouped according to Caribbean or Mainland background. We also performed an unbiased genome-wide association scan of urine albumin-Tocreatinine ratios.Overall, 41.4%of participantsweremale, 44.6%of participants had aCaribbean background, and the mean age of all participants was 46.1 years. The Caribbean background group, compared with the Mainland background group, had a higher frequency of two APOL1 alleles (1.0% versus 0.1%) and the HBB variant (2.0% versus 0.7%). In the Caribbean background group, presence of APOL1 alleles (2 versus 0/1 copies) or the HBB variant (1 versus 0 copies) were significantly associated with albuminuria (odds ratio [OR], 3.2; 95% confidence interval [95% CI], 1.7 to 6.1; and OR, 2.6; 95% CI, 1.8 to 3.8, respectively) and albuminuria and/or EGFR,60ml/min per 1.73m2 (OR, 2.9; 95%CI, 1.5 to 5.4; andOR, 2.4; 95%CI, 1.7 to 3.5, respectively). The urine albumin-To-creatinine ratio genome-wide association scan identified associations with the HBB variant among all participants, with the strongest association in the Caribbean background group (P=3.1310210 versus P=9.331023 for theMainland background group). In conclusion, African-specific alleles associate with CKD in Hispanics/Latinos, but allele frequency varies by Hispanic/Latino background/ancestry.