G1 is the major risk allele for hypertension-attributed nephropathy in Central Africa.

BACKGROUND

Sub-Saharan Africans exhibit a higher frequency of chronic kidney disease (CKD) than other populations. In this study, we sought to determine the frequency of apolipoprotein L1 () genotypes in hypertension-attributed CKD in Kinshasa, Democratic Republic of the Congo.

METHODS

We performed a case-control study identifying 162 subjects: 79 with hypertension-attributed CKD and 83 controls living in Kinshasa who were genotyped for risk variants between July 2013 and November 2016. We selected control subjects from the general population and matched them with the cases according to age. Logistic regression analysis was used to examine the relationship between high-risk genotypes and CKD.

RESULTS

The frequencies of the G1 and G2 alleles were 19.1 and 7.1%, respectively. The number of individuals with the G1 and G2 risk alleles was significantly higher in the CKD group (12.7%) than in the control group (2.4%), particularly in individuals with end-stage kidney disease (14.3%). Subjects carrying two risk alleles was strongly and independently associated with hypertension-attributed nephropathy, with an adjusted odds ratio of 7.7 (95% confidence interval 1.5-39.7; P = 0.014). The high-risk genotypes were G1/G1 and G1/G2, whereas G2/G2 was not found in the study population.

CONCLUSIONS

The results of this study demonstrate the association of high-risk genotypes with kidney disease in Kinshasa. The absence of G2/G2 may be consistent with powerful selective sweeps induced by infection. In contrast, the presence of G2/G2 among individuals of African ancestry in the USA may indicate relaxation of natural selection in a trypanosome-free environment.