High frequency of kidney and urinary tract anomalies in asymptomatic first-degree relatives of patients with CAKUT

Congenital anomalies of the kidney and urinary tract (CAKUT) commonly cause chronic kidney disease in children. While most CAKUT cases are sporadic, observed familial clustering suggests that the pathogenesis is influenced by genetic factors. The purpose of the present study is to determine the frequency of the kidney and urinary tract anomalies in asymptomatic first-degree relatives of patients with CAKUT. A total of 218 index patients and their families followed at an academic hospital in Ankara, Turkey, were enrolled in the study. Family histories revealed at least one other member with a known kidney or urinary tract disease in 50 % and CAKUT in 22.9 % of the families. All asymptomatic first-degree relatives of 180 index patients were screened for kidney and urinary tract anomalies using ultrasound. New anomalies were diagnosed in 116 asymptomatic first-degree relatives (23 %) in 87 families (48.3 %). When family histories and ultrasound findings of 180 index patients were evaluated together, 129 first-degree relatives in 92 families (51.1 %) had CAKUT. This study suggests that genetic mechanisms might be very important in the pathogenesis of apparently sporadic CAKUT. Identification of the underlying gene mutations will provide further insights into the knowledge of the kidney and urinary tract development and pathogenesis of CAKUT.