Mutations in PLCE1, TNS2, ACTN4, and TRPC6 are associated with nephrotic syndrome characterized by proteinuria.33,34,35,36,37,38 Products of these genes have important roles in podocyte function and integrity of the glomerular filtration barrier.39,40,41,42 The mechanisms of action of these genes in causing kidney damage are likely to be variable. The gene discussed is ACTN4; the disease is nephrotic syndrome.