WT1 and testicular agenesis: However, mutations in the Androgen Receptor (AR), Nuclear Receptor Subfamily 5 Group A Member 1 (NR5A1) and Wilms Tumor 1 (WT1) genes - classically associated with genital ambiguity or more severe forms of undervirilization - have recently been identified in cases with isolated proximal or even distal hypospadias, combined cryptorchidism and (distal) hypospadias or anorchia, and sequencing of these genes has been advocated in such cases [9-14].