Citrullinemia in Newborns: Causes, Symptoms and Treatment

Nitrogen is said to be as essential to our body as oxygen. Our body synthesises nitrogen to form ammonia which is required for various functions of the body. But when our body cannot properly synthesize nitrogen and instead stores it in our bloodstreams, it gives rise to a condition known as citrullinemia. This condition, often affecting newborns, belongs to another class of conditions which are genetic in nature. Read on to know more about citrullinemia and its treatment.

What Is Citrullinemia?

Citrullinemia is a genetic condition where the gene responsible for the synthesis of ammonia is missing. This results in excess ammonia being stored in the bloodstream, instead of being processed. As ammonia in excess quantities directly affects the nervous system, symptoms such as muscle weakness, seizures and swelling of the brain are noticed.

Typically, citrullinemia is of two types. The common citrullinemia and the milder form. Infants suffering from citrullinemia showcase the signs of the condition a few days after birth when the excess ammonia starts building up in the bloodstream.

The milder form of citrullinemia is noticed quite later in infancy or childhood. This condition is usually aggravated with long periods of fasting or during other illnesses or infection.

What Causes Citrullinemia?

The enzyme which is responsible for the synthesis of ammonia in our bodies is ASS1 gene. The mutation in this particular gene causes the disruption in the urea cycle in our body and prevents it from processing nitrogen effectively. When there is an excess amount of nitrogen in the body, it converts it into ammonia and gets stored in our bloodstream.

Excess ammonia in our bloodstream directly attacks our nervous system. The nerves do not function properly due to the excess ammonia present, which results in seizures and ataxia. It also has negative effects on our brain and other important organs of the body. Timely treatment is extremely important in severe citrullinemia cases.

What Are The Symptoms Of Citrullinemia?

The symptoms of citrullinemia often occur within a few days after birth, as the ammonia slowly starts building in the bloodstream. It is important to notice the following signs of high ammonia content in the blood-

-Excess sleepiness
- Lethargy
-Lack of appetite
- Vomitting

If not treated on time, the ammonia levels keep on increasing and you may notice symptoms such as

-Seizures
- Swelling of the brain
- breathing problems
-Hypotonia or low muscle tone
- Enlarged liver

Diagnosis Of Citrullinemia

Citrullinemia is a genetic condition and extremely rare. Almost 1 in every 2,50,000 newborns is affected by this condition.

Timely diagnosis of the condition may just be the matter of life and death for infants. The condition keeps worsening as the ammonia levels build up in the blood.

It may relatively be easier to diagnose the condition if any of the parents has a family history of citrullinemia. However, if there is no knowledge about the family history, certain tests can be carried out for the proper diagnosis of the condition.

Within the first few days of noticing any of the above symptoms, doctors may recommend a tandem mass spectrometry to determine the levels of ammonia in the muscles.

Further, a blood or urine analysis for amino acids can lead to confirmation of the condition when there are abnormal amounts of ammonia found in the blood and urine samples.

What Are The Treatment Options Available For Babies Diagnosed With Citrullinemia?

Though citrullinemia is a genetic condition, it can, fortunately, be treated. However, the success of the treatment is entirely based on how soon the symptoms are diagnosed. The treatment may also last a lifetime.

Given below are treatments options for infants who have just been diagnosed with citrullinemia and do not have huge amounts of ammonia build up in their blood.

-Babies who have developed citrullinemia a few days after their birth are usually started with medications that help prevent the storage of ammonia in the blood.

-Infants will be recommended a low-protein diet and special formulas to deal with the condition as a high-protein diet may cause ammonia to build up in the blood. Because of the fact that the child may remain in dietary restrictions for a lifetime, it is advised to consult a dietician who will chart up a customised diet keeping in mind your child's requirements.

In cases where the condition is diagnosed late and the infant is showing signs of nervous system dysfunction, the infant may immediately be admitted to the hospital where it is orally administered arginine to bring down the ammonia levels in their blood.

Furthermore, a dialysis may be required to stabilize the ammonia levels in the blood and the kidneys.

Some infants with citrullinemia have also undergone a liver transplant. Since the enzyme which is used to break down ammonia is present in the liver, this treatment may increase the life expectancy of infants suffering from this condition.

However, they may be on medication for a lifetime in order to prevent their bodies from rejecting the donor's liver. Also, this procedure has a lot of risks involved which should be thoroughly discussed with the physician.

Though, most of the infants who are diagnosed with the condition earlier go on to live normal lives, they may be on dietary restrictions and may have to undergo constant blood check-ups throughout their lives.