Citrullinemia Type 1 (CIT) is a rare genetic condition. CIT results from a mutation (error) in a person’s DNA. Due to this mistake, people with CIT are unable to remove ammonia, which is produced from amino acids, from the body and blood. Therefore, CIT is considered an amino acid condition. Amino acids are known as the “building blocks” of our body. They are created when the protein we get from food is broken down. We typically eat more protein than needed; therefore we often have more amino acids than we need. Enzymes (special proteins) breakdown the extra amino acids into organic acids, ammonia, and harmless products our body can get rid of. If one of the enzymes needed is missing or not working correctly, the amino acid is not broken all the way down and builds up in our system. Typically, we get rid of the ammonia in our body through urine. In this case the body is unable to make enough of the enzyme, arginosucinate synthetase (ASSI), which causes ammonia to build up and may be harmful.
There are two forms of type I CIT. The classic form occurs in infants, and the mild form occurs during childhood or adulthood. Typical symptoms of classic CIT type 1 include sleeping longer, tiredness, poor appetite, vomiting, seizures, irritability, and delayed growth. Treatment typically involves specific medications and supplements to lower the ammonia levels in the blood. Many babies are screened at birth so that treatment may begin early, however the conditions included in newborn screening vary state by state. For more information, visit Baby’s First Test.Talk with your doctor to determine which treatment options are best for your child. Support groups also a good source of information.