Discordant phenotypes in monozygotic twins with identical de novo WT1 mutation

Mutations in the WT1 gene, leading to Denys-Drash syndrome and Frasier syndrome, can also cause isolated steroid-resistant nephrotic syndrome (ISRNS). Previous studies have reported six pairs of monozygotic twins with WT1 mutations, including one presenting with discordant phenotypes with identical WT1 mutations being of paternal origin and five pairs of monozygotic twins presenting the same phenotype with identical WT1 mutations. In this study, we report on female monozygotic twins showing discordant phenotypes with an identical de novo WT1 mutation, R394W, and presenting incomplete Denys-Drash syndrome and ISRNS.