Congenital Anomalies of the kidney and urinary tract: pediatric origins and adult outcomes

Congenital anomalies of the kidney and urinary tract (CAKUT) are a heterogeneous group of structural defects that arise from disordered nephrogenesis. CAKUT accounts for 20%-30% of all prenatal anomalies, with a pooled birth prevalence of 3.83 per 1000. The pathogenesis reflects disrupted ureteric bud-metanephric mesenchyme signalling and early transcriptional programs. Genetic disorders underlie approximately one-fifth of cases, with monogenic causes (notably HNF1β and PAX2) and copy number variants being particularly prevalent in syndromic presentations. The broad phenotypic expression underscores the value of genetic testing in cases of severe or syndromic disease, familial dysplasia, bilateral dysplasia (often cystic), and idiopathic chronic kidney disease/kidney replacement therapy (KRT). We will focus on two defects, being the most common causes of pediatric CKD: kidney dysplasia/hypoplasia and lower urinary tract obstruction. Chronic kidney damage associated with CAKUT progresses slowly, while the peak need for KRT occurs in adolescence, the average commencement is around 31 years of age. These patients carry a heightened risk of cardiovascular and metabolic disease, neurocognitive impairment and a small increased risk of malignancy. A life-course model of care, integrating targeted genetic diagnosis with proactive management of CKD and its extrarenal sequelae, is essential to improve outcomes.