APOL1: Genetic Epidemiology, Biology and Associated Diseases
Coker, M. M.1,2, Akinyemi, R.O.1, Bakare, A.A.2 and Owolabi, M.O.3
1Institute for Advanced Medical Research and Training, College of Medicine, University of Ibadan, Ibadan, Nigeria;
2Department of Zoology, University of Ibadan, Ibadan, Nigeria;
3Department of Medicine, College of Medicine, University of Ibadan, Ibadan, Nigeria
APOL1 is a gene restricted to the genomes of humans and some non-human primates. It is unique among its other gene family members in its possession of a signal peptide that confers on it the ability to be exported out of the cell and into the blood stream. This gene has been implicated in various diseases with variants endemic to African ancestry.
We reviewed the genetic epidemiology, biology and diseases associated with APOL1. Literature review search was carried out using combination of terms including “apolipoproteins”, “apolipoprotein L”, “APOL1 biology”, “genetics of APOL1”, “CKD and APOL1”,” APOL1 and associated diseases”. Literature was searched until November 2017.
APOL1 gene functions include innate immunity against intracellular pathogens, programmed cell death, autophagy, metabolism and transport of lipids. The trypanolytic ability of APOL1 makes it prevalent in Africa where trypanosomes are endemic. Two of its variants G1 and G2 have been able to overcome the virulent factor produced by Trypanosoma brucei brucei and T. b. rhodisiense to counter its trypanolytic factor. Although these alleles have given resistance to parasite infection, they are strongly associated with various forms of kidney disorders such as collapsing glomerulopathy, focal segmental glomerulosclerosis, systemic lupus erythematosus and other diseases including schizophrenia, stroke, cancer, and preeclampsia. G1 and G2 alleles range in frequency in different geographical regions of sub Saharan Africa with the lowest frequencies in East Africa and the highest in West Africa.
The elucidation of the APOL1 gene has deepened understanding of racial disparities in health, disease and predisposition of different disorders. Further insights are still required to deliver relevant translational benefits for development of new biomarkers, preventive and therapeutic interventions in relation to the APOL1 gene variants.
Keywords: APOL1, Trypanolytic factor, Lipoprotein particles, Apolipoprotein, disease