Even though an individual functional relevance for this myriad of WT1 isoforms has yet to established, mutations in the KTS splice site have been documented in patients with Frasier syndrome [83], meaning gonadal dysgenesis, ambiguity to complete transformation of male external genitalia to a female phenotype and progressive glomerulonephropathy (focal segmental glomerulosclerosis). Here, WT1 is linked to focal segmental glomerulosclerosis.