It occurs as either an isolated ocular abnormality or as part of the Wilms-tumour-aniridia-genital anomalies-retardation (WAGR) syndrome, caused by a deletion in regions including PAX6 and WT1. Individuals with WAGR syndrome are at a higher risk of developing Wilm’s tumour, a rare kidney cancer mainly affecting children (Moosajee et al. 2018). Here, WT1 is linked to WAGR syndrome.