Congenital Kidney Anomalies and Renal Function Dynamics

Congenital anomalies of the kidney and urinary tract encompass a broad spectrum of developmental defects that may affect nephron number, renal architecture and urinary outflow. Reduced nephron endowment, as seen in unilateral renal agenesis, dysplasia or early nephron loss, triggers compensatory adaptations including hypertrophy of remaining nephrons, increases in single‐nephron glomerular filtration and alterations in renal haemodynamics. While these mechanisms can normalise overall glomerular filtration rate (GFR) in the short term, sustained hyperfiltration and structural remodelling predispose to glomerulosclerosis, tubulointerstitial fibrosis and eventual decline in renal function. Animal models of congenital nephron deficit have elucidated key roles for the renin–angiotensin–aldosterone system, nitric oxide bioavailability and sex‐specific pathways in determining the trajectory of renal injury. Clinical cohorts confirm a high lifetime prevalence of hypertension, proteinuria and chronic kidney disease in individuals born with a solitary functioning kidney. Emerging biomarkers and early interventions seek to stratify risk and mitigate long‐term complications through tailored surveillance and targeted pharmacotherapy.

Research from Nature Portfolio

Renal nitric oxide deficiency has been implicated in early dysfunction of a solitary functioning kidney. Studies in a sheep model of foetal unilateral nephrectomy demonstrate reduced basal urinary nitrate and nitrite excretion and attenuated haemodynamic responses to nitric oxide inhibition. These findings suggest that diminished nitric oxide bioavailability in the perinatal period contributes to glomerular and tubular injury, laying the groundwork for hypertension and chronic kidney disease in later life.

Experimental uninephrectomy during active nephrogenesis in rats reveals that nephron loss in this vulnerable window yields more severe renal sequelae than loss after completion of nephrogenesis. Animals subjected to nephron reduction during nephrogenesis exhibited exaggerated compensatory growth, heightened glomerulosclerosis, podocyte injury and tubulointerstitial inflammation at one year of age, independent of overt hypertension. This work underscores the critical impact of developmental timing on the severity of long‐term renal damage.

Congenital Kidney Anomalies and Renal Function Dynamics publication trend

The graph below shows the total number of articles in congenital kidney anomalies and renal function dynamics across all publications each year (not limited to Nature Index journals).

Technical terms

Congenital anomalies of the kidney and urinary tract (CAKUT): Developmental malformations affecting renal structure or urinary drainage present at birth.

Solitary functioning kidney (SFK): A single operational renal unit arising from agenesis, dysplasia or surgical removal of one kidney.

Nephron: The fundamental functional unit of the kidney, comprising a glomerulus and associated tubular segments.

Hyperfiltration: Compensatory increase in individual nephron filtration rate to maintain total GFR in the context of reduced nephron number.

Glomerular filtration rate (GFR): A quantitative measure of plasma volume filtered by the glomeruli per unit time, reflecting overall kidney function.

Renal functional reserve (RFR): The capacity of the kidney to augment GFR above baseline in response to physiological or pharmacological stimuli.

References

1. Physiology and Pathophysiology of Compensatory Adaptations of a Solitary Functioning Kidney. Frontiers in Physiology (2020).
2. Renal Nitric Oxide Deficiency and Chronic Kidney Disease in Young Sheep Born with a Solitary Functioning Kidney. Scientific Reports (2016).
3. Neonatal nephron loss during active nephrogenesis – detrimental impact with long-term renal consequences. Scientific Reports (2018).
4. Beneficial effects of brief early life angiotensin-converting enzyme inhibition wane with time in sheep with solitary functioning kidney. Clinical Science (2023).
5. Sex differences in long-term kidney fibrosis following neonatal nephron loss during ongoing nephrogenesis. Molecular and Cellular Pediatrics (2023).
6. Uncovering risk factors for kidney injury in children with a solitary functioning kidney. Kidney International (2022).