Renal Agenesis

What Is Renal Agenesis?

Renal agenesis is a genetic disorder characterized by absence or deficiency of one or both kidneys. There are two types of renal agenesis: idiopathic (does not occur in any other family) and acquired (occurs during fetal development). Idiopathic renal agenesis occurs when there is no known cause. Acquired renal agenesis usually results from damage to the developing kidney. Some cases may result from other causes such as infection, trauma, or chemotherapy drugs.

The condition affects males and females equally; however, it is more common in boys than girls. The prevalence rate varies between 1% and 5%.

Most affected individuals live into their early twenties and have normal lives. However, some individuals die before reaching adulthood due to complications of the disease.

There are three main types of renal agenesis: idiopathic, acquired and inherited. All three forms affect different organs in different ways.

For example, idiopathic renal agenesis affects all the major body systems but most commonly affects the heart and lungs. Acquired renal agenesis involves damage to only one organ while hereditary type is characterised by defects affecting several organs in varying degrees.

What Are the Symptoms of Renal Agenesis?

The most common symptom of this condition is an abnormal increase in blood levels of amino acids, in particular, p-aminobutyric acid (PABA). Other symptoms may include:

Breathing issues due to low oxygen supply

Abnormal heartbeats

Liver dysfunction

Spinal cord damage

Hearing loss

Seizures

Muscle weakness.

These symptoms may be present from birth; however, some symptoms may take up to two years to appear.

What Are the Causes of Renal Agenesis?

The exact cause of this disease is still unknown; however, it is known to be an inherited disorder. The condition is caused by a mutation (change) in certain genes that are responsible for the normal functioning of the body organs.

Family history plays a major role in this disease. Renal agenesis is more common in babies born to parents who have a family history of this condition.

It is also believed to be caused by the mother’s intake of specific drugs such as Valproic acid, which is used to treat epilepsy and mood disorders such as bipolar disorder (manic depression). The drug damages the fetus’s organs during the first three months of pregnancy.

How Is Renal Agenesis Diagnosed?

No specific tests can be done to diagnose this condition; however, your doctor can make the diagnosis based on a complete medical history and a physical examination of your baby. The doctor will use ultrasound to examine your baby’s internal organs after birth. If you or any of your close family members have a history of renal agenesis, your doctor may suggest collecting a sample of the amniotic fluid for further testing.

How Is Renal Agenesis Treated?

There is no specific treatment to reverse the effects of this condition. Renal agenesis affects different organs in different ways and the effects may vary from one baby to another. Some babies may require immediate medical attention while others may lead normal lives without any complications. It all depends on the severity of the condition.

The most common treatment for babies with this condition involves continuous monitoring using a fetal heart monitor to check the baby’s heart rate and oxygen levels. Other treatments may include:

Oxygen supply to increase the level of oxygen in the blood.

A diuretic to remove excess water and sodium from the body.

Digoxin to strengthen the heartbeats.

Acetazolamide to reduce the build-up of fluid in the brain.

Intravenous administration of glucose to provide an immediate source of energy to vital organs.

In some cases, kidney transplant or dialysis therapy may be required. This condition is often fatal and your baby may die during birth or within a few months of birth.

What Is the Prognosis of Renal Agenesis?

The prognosis depends on the extent of organ damage and the organs involved. Babies with this condition usually have a shortened life span. The earlier the condition is diagnosed, the better are the chances of survival.

A baby born with renal agenesis will require constant monitoring to ensure adequate supply of oxygen and nutrients. Intravenous administration of glucose and acetazolamide, a diuretic, may be needed to reduce the buildup of fluid in your baby’s brain.

Does Renal Agenesis Affect Only Newborns?

No. It can also affect adults. Damage to the kidneys caused by renal agenesis is usually permanent and may become life-threatening later in life if proper treatment is not provided. Adult patients of renal agenesis may suffer from fatigue, loss of appetite, nausea, vomiting, and muscle weakness. They may also suffer from frequent urinary tract and respiratory infections.

Other complications may also arise due to the buildup of toxic wastes in the body if the damaged kidneys are not functioning properly. In some cases, a damaged kidney may start leaking protein into the urine, which may damage the second kidney, resulting in renal failure.

A kidney transplant may be necessary to save the patient’s life in such situations. Patients with renal agenesis are usually advised to undergo frequent checkups to assess kidney function and keep a check on the buildup of wastes in the body.

What Is the Long-Term Outlook of Renal Agenesis?

Most babies with renal agenesis do not survive past birth. Those who do usually don’t live for more than a few months. The outlook improves if the condition is diagnosed before birth. In such cases, the baby may be born with some developmental difficulties and may need medical treatment throughout its life. Kidney transplantation or dialysis therapy may help such patients lead a normal life.

Prevention

There is no way to prevent renal agenesis before birth. However, parents can take certain measures to reduce the possibility of their baby developing it after birth.

Some of these measures include:

Quitting Smoking: Maternal smoking during pregnancy increases the risk of premature birth and can also damage the baby’s lungs. Studies have linked maternal smoking with renal agenesis.

Limiting the Use of Alcohol: Alcohol consumption during pregnancy increases the risk of miscarriage, stillbirth, and other birth defects. It may also damage the baby’s developing kidneys.

Controlling High Blood Pressure: Maternal high blood pressure increases the risk of fetal death and can cause life-threatening health conditions for the baby after birth.

Gestational diabetes significantly increases the risk of your baby developing renal agenesis. Hence, it is necessary to maintain proper blood sugar levels during your pregnancy.

Excessive weight gain in your pregnancy may also increase the risk of your baby developing renal agenesis. Hence, you should avoid eating an unhealthy diet and gaining too much weight during your pregnancy.

Diagnosis

Your doctor will usually take a medical history and examine you before diagnosing you with renal agenesis. He may ask you questions about your family’s medical history, such as whether any of your near relatives had a kidney problem.

Your doctor will also ask you about any medications that you may be taking. If you are taking any such medicines, he will ask you to stop taking them before the examination.

He may also ask you to discontinue any herbal supplements that you may be taking.

Your doctor will also ask you to describe the symptoms that you are experiencing. In addition, he may advise you to go for certain tests to diagnose your condition.

A renal ultrasound may be performed to examine your kidneys and look for any tumors or cysts.

A blood and urine sample may be taken to analyze the content of your urine and find out whether the level of any important minerals and salts in your body is normal or not.

Long Term Prognosis

The long-term outlook for patients with renal agenesis is usually good as long as the patient receives appropriate medical treatment before and after birth. The exact prognosis depends on the type of agenesis present and how much of the kidney is missing.

In some cases, the baby’s body may be able to compensate for the missing kidney.

In some cases, only a small part of one of the baby’s kidneys may be missing. In such cases, the baby may have a normal life expectancy.

However, the baby may have to undergo kidney transplantation or dialysis therapy in the future.

In some cases, babies with renal agenesis do not survive past birth. In such cases, medical treatment is usually given only if it can help the baby’s mother.

Treatment

The treatment for your condition depends on the severity of the disease and whether or not you are experiencing any complications. Your doctor will advise you about the best course of treatment after examining you.

In some cases, both mother and baby require medical treatment. Some of the treatment options that may be recommended for you or your child include:

Vitamin injections: Vitamin B-6 is normally absorbed by the body through food. However, when taken in large amounts by mouth, it can be absorbed through the skin.

Vitamin B-6 is required for the production and maintenance of red blood cells, so its deficiency can lead to anemia. It also helps in the formation of protein and helps in the metabolism of carbohydrates.

Vitamin B-12 is another water-soluble vitamin that is naturally present in some foods like meat, fish, poultry, eggs, milk, and certain types of vegetables. It helps in the formation of blood and prevents anemia.

It also maintains the body’s nerve tissues and helps in metabolizing fat.

Your doctor may recommend that you receive regular injections of B-complex vitamins and folic acid, which are water-soluble and essential for the normal functioning of the body.

Surgery: In some cases, surgery may be recommended to treat urogenital defects. This surgery is most commonly recommended for babies born with a posterior renal fusion.

In such cases, the surgeon will create a nephrostomy, which is an opening between the fused kidneys, to allow the urine to drain normally.

A ureterostomy may also be performed to treat babies born with posterior renal fusion. Ureterostomy involves creating a hole between the baby’s bladder and the outside of its body to allow the urine to drain away.

Treatment for polycystic kidney disease or cystic kidney dysplasia is usually surgical. The doctor will remove the affected kidney through a surgical procedure.

Sources & references used in this article:

Bilateral renal agenesis by EL Pøtter – The Journal of pediatrics, 1946 – Elsevier

Renal agenesis and the absence of enteric neurons in mice lacking GDNF by MP Sánchez, I Silos-Santiago, J Frisén, B He, SA Lira… – Nature, 1996 – Springer

Focal and segmental glomerulosclerosis and porteinuria associated with unilateral renal agenesis. by DD Kiprov, RB Colvin, RT McCluskey – Laboratory investigation; a …, 1982 – ncbi.nlm.nih.gov

Prognosis of patients with unilateral renal agenesis by LR Argueso, ML Ritchey, ET Boyle, DS Milliner… – Pediatric …, 1992 – Springer