Long-term outcome in a case series of Denys-Drash syndrome.

Background: Denys-Drash syndrome (DDS) is a rare disease caused by mutations in exons 8 and 9 of the gene. It is characterized by the association of early onset steroid-resistant nephrotic syndrome (SRNS), Wilms' tumour and, in some patients, intersex disorders, with increasing risk of gonadoblastoma. There are few published data concerning the long-term outcome of patients with DDS. The aim of this study was to report our experience.

Methods: Data were collected from five children (three boys) with confirmed DDS diagnosed from 1996 to 2017. The mean follow-up of these patients was 16 years.

Results: The patients presented with SRNS and diffuse mesangial sclerosis at renal biopsy. All patients were hypertensive and progressed to end-stage kidney disease, initiating dialysis at a mean age of 28 months. Three patients developed Wilms' tumour 9 months after the SRNS was identified, which was treated by nephrectomy and chemotherapy. All five patients received kidney transplantation. SRNS did not recur after transplantation in any of the patients and graft survival was similar to that of other kidney transplant recipients in our programme. All three boys had ambiguous genitalia and cryptorchidism but a confirmed male karyotype (46, XY). One girl presented with gonadal agenesis, whereas the other one had normal female ovarian tissue and external genitalia. Both girls had a female karyotype (46, XX). Gonadoblastoma was not observed at any case.

Conclusions: Early DDS recognition in patients with SRNS is crucial due to its low prevalence, the specific treatment approach required and early detection of Wilms' tumour. Few data are available regarding long-term outcomes.