What are congenital anomalies of the kidney and urinary tract (CAKUT)?
Congenital anomalies of the kidneys and urinary tract (CAKUT) include different abnormalities that occur when the kidneys and other parts of the urinary tract (including the ureters, bladder and urethra) do not develop properly in the womb.
- congenital – the problem is present at birth
- anomaly – different from normal
Information about lots of CAKUT conditions can be found on the infoKID website.
CAKUT conditions include:
- renal agenesis – one or both kidneys do not develop in the womb
- renal hypoplasia - one or both of the kidneys are smaller than normal
- renal dysplasia – part of one or both kidneys do not fully develop in the womb
- multicystic dysplastic kidney - abnormally developed kidneys with cysts (small fluid filled sacs)
- duplex kidneys – a double kidney on one or both sides of the body
- ectopic kidney - the kidney is not in the usual position
- horseshoe kidney – one U-shaped instead of two separate kidneys
- pelvi-ureteric junction (PUJ) dysfunction or obstruction – a narrowing or blockage where the kidney joins the ureter
- vesicoureteral reflux (VUR) - when urine passes back up the wrong way, towards one or both kidneys
- vesico-ureteric junction obstruction (VUJO) - a narrowing, hold up or blockage where the ureter meets the bladder
- posterior urethral valves (PUV) - a blockage in the urethra of boys
- bladder exstrophy and epispadias - the skin over the lower abdominal wall (the bottom part of the tummy) does not form properly, so the bladder is open and exposed on the outside of the abdomen. Epispadias is when the urethra does not form properly.
CAKUT conditions are present from birth and are the most common cause of chronic kidney disease (CKD) in children and young people. 1 in 2 people under the age of 30 with chronic kidney disease (CKD) have a CAKUT.
Overall, CAKUT conditions affect around 3 in every 1,000 people in the UK.
What causes CAKUT?
Research into the causes of CAKUT conditions is ongoing. It is currently believed that a combination of environmental and genetic factors (changes in DNA) affect the development of the kidneys and urinary tract during pregnancy.
If diabetes is present during pregnancy, babies have a slightly higher chance of being born with CAKUT.
What are the signs and symptoms of CAKUT?
The signs and symptoms vary depending on the precise condition. Some conditions do not cause any or only minor symptoms whereas others can have a big impact on how the kidneys function.
Babies and young children may have frequent urinary tract infections (UTIs), problems passing urine or difficulty with potty training.
Older children and adults may have problems emptying their bladders and may need to use a urinary catheter to help them pass urine.
How are CAKUT conditions diagnosed?
Some CAKUT conditions are diagnosed before birth on an antenatal ultrasound scan. Other conditions are found in childhood or adulthood during a scan for another reason, such as a urinary tract infection (UTI) or after an accident.
Ultrasound scans are used to see how the kidneys have formed and whether there is a blockage. Tests such as a micturating cystourethrogram (MCUG) or MAG3 scan can investigate whether there are any problems passing urine and how the kidneys are working.
Blood and urine tests are used to monitor kidney function.
Genetic testing may be offered if your healthcare team think that your CAKUT condition may be inherited, if there are other members of your family who also have CAKUT or if other parts of the body are affected.
Do CAKUT conditions affect other parts of the body?
Some CAKUT conditions may occur alongside other conditions which can affect other parts of the body.
Do CAKUT conditions run in families?
A small number of CAKUT conditions are inherited. Over 50 different genes (sets of instructions in our DNA) have been linked to CAKUT but these changes are only found in around 1 in 10 people with a CAKUT condition.
How are CAKUT conditions disease treated?
Treatment varies depending on the precise condition and how serious it is. Some CAKUT conditions do not need any treatment and any problems resolve themselves over time.
Regular monitoring of blood pressure and kidney function is recommended.
Treatment may include ways to help empty the bladder. It may also include medicine support for kidneys that do not function normally.
Specialist clinical teams may offer additional support to young children to promote independence with potty training and toileting. This may include supporting practical approaches to potty training, medication, stoma care and management and catheters.
Older children and adults may need help to empty their bladders, such as using a urinary catheter.
Antibiotics may be prescribed for urinary tract infections.
Occasionally surgery may be needed on the affected part of the urinary tract.
Severe cases of CAKUT may be associated with poorly developed kidneys that do not function well. This may lead to kidney failure in childhood or as a young adult, which may require dialysis or transplantation.
Where can I get more information or support about CAKUT?
ERIC, the children’s bowel and bladder charity, has more information on some CAKUT conditions.
If you know of any specific CAKUT patient groups, please let us know so we can share their details.
Publication date: 11/2025
Review date: 11/2028
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