Our data demonstrate that APOL1 G1 (I384M/S342G) confers loss of proper APOL1 function in the developing zebrafish kidney, while APOL1 G2 is acting in a dominant-negative manner to induce nephropathy, possibly through suppression of myh9. These data indicate that the risk conferred by the APOL1/MYH9 locus is likely to be governed by a more complex model than recessive patterning as suggested previously. The gene discussed is APOL1; the disease is kidney disorder.