Our findings support the hypothesis that the G189R-PAX2 mutation has a dual effect in inducing the adult onset of FSGS: one, the most relevant for the onset of the pathology, in the early stage of kidney development, that by compromising ureteric bud development may predispose the kidney to the development of FSGS, and a second effect in adult podocytes, which are not able to properly counteract environmental triggers, making them more susceptible to injury. The gene discussed is PAX2; the disease is focal segmental glomerulosclerosis.