Congenital urinary tract anomalies are a variable finding associated with nevoid basal cell carcinoma syndrome

Introduction: Nevoid basal cell carcinoma syndrome (NBCCS) is a rare autosomal dominant disorder classically associated with multiple basal cell carcinomas, odontogenic keratocysts and skeletal anomalies. However, its significant phenotypic heterogeneity often delays the diagnosis. Here, we undertake the first comprehensive characterisation of NBCCS and congenital urinary tract anomalies.

Methods: Clinical evaluation followed by genetic testing was performed on a proband with congenital hydronephrosis due to ureteropelvic obstruction. Then, a cohort of patients with molecularly confirmed NBCCS evaluated at a single institution was analysed, followed by a comprehensive review of the literature.

Results: The novel, non-canonical splice-site variant c.349+4 delA in PTCH1 was detected in a proband, with RNA analysis confirming exon 2 skipping. Of the additional nine NBCCS cases examined at our institution, a second proband with a nonsense variant in PTCH1 was identified with renal agenesis and a bladder diverticulum. A literature review then yielded 11 case reports of patients with congenital urinary tract anomalies, most frequently renal agenesis.

Discussion: Congenital urinary tract anomalies are a variable finding in NBCCS. Renal ultrasound may be warranted at the time of initial diagnosis, if not previously performed. Moreover, PTCH1 should be included in multigene panels that assess for congenital urinary tract disorders.