Genetic spectrum of CAKUT and risk factors for kidney failure: a paediatric multicentre cohort study

BACKGROUND: Congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of kidney failure in children with phenotypic and genotypic heterogeneity. Our objective was to describe the genetic spectrum and identify the risk factors for kidney failure in children with CAKUT. METHODS: Clinical and genetic data were derived from a multicentre network [Chinese Children Genetic Kidney Disease Database (CCGKDD)] and the Chigene database. A total of 925 children with CAKUT who underwent genetic testing from 2014 to 2020 across China were studied. Data for a total of 584 children were obtained from the CCGKDD, including longitudinal data regarding kidney function. The risk factors for kidney failure were determined by the Kaplan–Meier method and Cox proportional hazards models. RESULTS: A genetic diagnosis was established in 96 of 925 (10.3%) children, including 72 (8%) with monogenic variants, 20 (2%) with copy number variants (CNVs) and 4 (0.4%) with major chromosomal anomalies. Patients with skeletal abnormalities were more likely to have large CNVs or abnormal karyotypes than monogenic variants. Eighty-two patients from the CCGKDD progressed to kidney failure at a median age of 13.0 years (95% confidence interval 12.4–13.6) and 24 were genetically diagnosed with variants of PAX2, TNXB, EYA1, HNF1B and GATA3 or the 48,XXYY karyotype. The multivariate analysis indicated that solitary kidney, posterior urethral valves, bilateral hypodysplasia, the presence of certain variants and premature birth were independent prognostic factors. CONCLUSIONS: The genetic spectrum of CAKUT varies among different subphenotypes. The identified factors indicate areas that require special attention.