Congenital anomalies of the kidney and urinary tract (CAKUT) is an umbrella term encompassing a broad spectrum of developmental disorders affecting the kidney and urinary tract. These conditions include: renal agenesis, hypo/dysplasia, multicystic dysplasia, duplication anomalies, obstructive lesions (uretero-pelvic or uretero-vesical junction), abnormalities of the ureter or urethra including megaureter, posterior urethral valves (PUV) and urethral stenosis, as well as vesicoureteral reflux (VUR). Given the diverse morphological and functional spectrum of CAKUT – clinical course and outcomes are highly variable. Some children with milder phenotypes will be completely asymptomatic (perhaps even evading clinical detection) while others will face a life of kidney replacement therapy (KRT). When considered as a group, CAKUT accounts for the majority of chronic kidney disease (CKD) in children. It is also increasingly recognised that CAKUT accounts for a burden of CKD and KRT in adults, which may have previously been under appreciated or attributed to other causes.1,2

Antenatal detection of CAKUT is improving, and consequently, these conditions are presenting more frequently to clinicians. Protecting nephrons, to preserve kidney function for as long as possible is the priority for both medical and surgical caregivers. The emerging realisation that even children with apparently milder CAKUT phenotypes, may encounter functional issues as they progress into adulthood, is a very important one for pediatric clinicians to consider. Developing an individualised management plan which balances over-medicalization with appropriate protection for these apparently well children, is a particular challenge.

Scientific research has contributed to significant advancement in our understanding of kidney development and maldevelopment over recent decades. This has informed management strategies to guide the care of these children. The purpose of this review will be to provide an overview of CAKUT, with a focus on the embryological and developmental processes involved. We will review the proposed genetic, and environmental etiological factors involved. We will discuss the contribution of mouse models, stem cell research and organoid work to the field and provide some insights into the future direction of CAKUT research.