Two independent variants of the APOL1 gene found in African haplotypes carrying signatures of natural selection have been shown to confer protection against the acute version of sleeping sickness caused by T. b. rhodesiense, while at the same time increasing risk of kidney disease when inherited from both parents.
A third, morphologically identical species, Trypanosoma brucei brucei, infects domestic and wild animals but does not cause disease in humans because it is lysed by apolipoproetin L1 in the high-density lipoprotein fraction of human serum.
The APOL1 gene has been proposed as a major genetic risk locus for a spectrum of nondiabetic renal failure in individuals of African origin, these include HIV-associated nephropathy (HIVAN), primary nonmonogenic forms of focal segmental glomerulosclerosis, and hypertension affiliated chronic kidney disease not attributed to other etiologies.
APOL1 |