High population frequencies of APOL1 risk variants are associated with increased prevalence of non-diabetic chronic kidney disease in the Igbo people from south-eastern Nigeria

Nephron Clin Pract. 2013;123(1-2):123-8. doi: 10.1159/000353223. Epub 2013 Jul 13.


Background: Continental Africa is facing an epidemic of chronic kidney disease (CKD). APOL1 risk variants have been shown to be strongly associated with an increased risk for non-diabetic kidney disease including HIV nephropathy, primary non-monogenic focal and segmental glomerulosclerosis, and hypertension-attributed nephropathy among African ancestry populations in the USA. The world's highest frequencies of APOL1 risk alleles have been reported in West African nations, overlapping regions with a high incidence of CKD and hypertension. One such region is south-eastern Nigeria, and therefore we sought to quantify the association of APOL1 risk alleles with CKD in this region.

Methods: APOL1 risk variants were genotyped in a case-control sample set consisting of non-diabetic, CKD patients (n = 44) and control individuals (n = 43) from Enugu and Abakaliki, Nigeria.

Results: We found a high frequency of two APOL1 risk alleles in the general population of Igbo people of south-eastern Nigeria (23.3%). The two APOL1 risk allele frequency in the CKD patient group was 66%. Logistic regression analysis under a recessive inheritance model showed a strong and significant association of APOL1 two-risk alleles with CKD, yielding an odds ratio of 6.4 (unadjusted p = 1.2E-4); following correction for age, gender, HIV and BMI, the odds ratio was 4.8 (adjusted p = 5.1E-03).

Conclusion: APOL1 risk variants are common in the Igbo population of south-eastern Nigeria, and are also highly associated with non-diabetic CKD in this area. APOL1 may explain the increased prevalence of CKD in this region.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Apolipoprotein L1
  • Apolipoproteins / genetics*
  • Diabetes Mellitus / ethnology
  • Diabetes Mellitus / genetics
  • Female
  • Genetic Markers / genetics
  • Genetic Predisposition to Disease / epidemiology*
  • Genetic Predisposition to Disease / genetics*
  • Genetic Variation / genetics*
  • Humans
  • Lipoproteins, HDL / genetics*
  • Male
  • Middle Aged
  • Nigeria / epidemiology
  • Polymorphism, Single Nucleotide / genetics*
  • Prevalence
  • Renal Insufficiency, Chronic / ethnology*
  • Renal Insufficiency, Chronic / genetics*
  • Risk Factors


  • APOL1 protein, human
  • Apolipoprotein L1
  • Apolipoproteins
  • Genetic Markers
  • Lipoproteins, HDL