Diversity of renal phenotypes in patients with WDR19 mutations: Two case reports

WDR19 has been reported as a causative gene of nephronophthisis-related ciliopathies. Patients with WDR19 mutations can show various extrarenal manifestations such as skeletal disorders, Caroli disease, and retinal dystrophy, and typically display nephronophthisis as a renal phenotype. However, there is limited information on the renal phenotypes of patients with WDR19 mutations. We report two Japanese infants with Sensenbrenner syndrome caused by WDR19 mutations who demonstrated different features in renal ultrasound and histopathological results, despite several common extrarenal manifestations. Patient 1 had normal sized and hyperechogenic kidneys with several small cysts and histopathological findings compatible with infantile nephronophthisis. Renal ultrasound of Patient 2 showed enlarged kidneys with diffuse microcysts resembling those of autosomal recessive polycystic kidney disease. Her renal histopathology revealed dysplastic kidney with diffuse glomerular cysts. Genetic testing identified compound heterozygous mutations in WDR19 in both patients (Patient 1: c.953delA, c.3533G > A, Patient 2: c.2645 + 1G > T, c.3533G > A). Our patients suggest that WDR19 mutations can cause dysplastic kidney in addition to nephronophthisis pathologically. In addition, differences in pathology of the kidneys from WDR19 mutations may result in heterogeneous features in renal ultrasound findings. Renal phenotypes from WDR19 mutations may thus be more diverse than previously reported. Extrarenal manifestations and genetic testing can therefore help to diagnosis this disease more precisely.