Targeted Exome Sequencing Provided Comprehensive Genetic Diagnosis of Congenital Anomalies of the Kidney and Urinary Tract.

Congenital anomalies of the kidney and urinary tract (CAKUT) are the most common cause of chronic kidney disease in children. The search for genetic causes of CAKUT has led to genetic diagnosis in approximately 5-20 % of CAKUT patients from Western countries. In this study, genetic causes of CAKUT in Korean children were sought using targeted exome sequencing (TES) of 60 genes reported to cause CAKUT in human or murine models. We identified genetic causes in 13.8% of the 94 recruited patients. Pathogenic single nucleotide variants of five known disease-causing genes, HNF1B, PAX2, EYA1, UPK3A, and FRAS1 were found in 7 cases. Pathogenic copy number variations of 6 patients were found in HNF1B, EYA1, and CHD1L. Genetic abnormality types did not significantly differ according to CAKUT phenotypes. Patients with pathogenic variants of targeted genes had syndromic features more frequently than those without (p < 0.001). This is the first genetic analysis study of Korean patients with CAKUT. Only one-seventh of patients were found to have pathogenic mutations in known CAKUT-related genes, indicating that there are more CAKUT-causing genes or environmental factors to discover.