APOL1 and chronic kidney disease: APOL1-associated CKD risk is inherited as a recessive trait, and a high risk genotype is any combination of the two APOL1 risk alleles known as G1 (rs73885319, p.S342G and rs60910145, p.I384M) and G2 (rs71785313, p.NYK388K), with the common alleles at each site not associated with CKD referred to as G0.