CAKUT

CAKUT, or congenital anomalies of the kidney and urinary tract, encompasses a range of developmental disorders affecting the kidney tissue and/or the urinary tract. Examples include renal agenesis, hypoplasia, and dysplasia, as well as hydronephrosis, ureteropelvic junction obstruction, posterior urethral valves, and vesicoureteral reflux. CAKUT may be detected prenatally or after birth.

Most CAKUT forms are multifactorial, arising from genetic predisposition interacting with environmental factors during organ development. Genes such as PAX2, HNF1B, SALL1, and ROBO2 have been implicated in ureteric bud branching and nephron formation. The same gene can produce different phenotypes, and CAKUT can occur in isolation or as part of a syndrome.

Clinical presentation varies. Prenatal ultrasound may show hydronephrosis; after birth, symptoms include urinary tract infections, poor urine flow, abdominal masses, or growth concerns. Evaluation combines postnatal ultrasound, functional imaging (nuclear renography), and voiding cystourethrography when reflux or obstruction is suspected. Genetic testing is considered for syndromic or familial cases.

Management is tailored to the specific anomaly and may range from observation to surgery. Procedures include pyeloplasty for UPJ obstruction, ureteral reimplantation for reflux, and valve ablation for obstructive conditions. Long-term care emphasizes monitoring kidney growth and function, preventing infections, and addressing chronic kidney disease risk.

CAKUT is a leading cause of pediatric chronic kidney disease and contributes substantially to congenital kidney and urinary tract abnormalities worldwide. Outcomes vary widely, underscoring the importance of early recognition and multidisciplinary management.