What Is Citrullinemia?
Citrullinemia is an inherited disorder that presents in two forms: a type I form and a type II form. The type I form is more common than is the type II form, as about 1 in about 60,000 people worldwide have the type I form and about 1 in every 100,000-230,000 individuals suffer from the type II form. The type II form is particularly prevalent among Japanese individuals. Both forms are usually debilitating and are often life-threatening.
Type I citrullinemia typically presents shortly after birth and is due to extreme build up of ammonia in the body. Common symptoms include vomiting, seizures, frequent sleeping and even losing consciousness. Infants who suffer from type I citrullinemia are at heightened risk of coma and death.
In some sufferers, type I citrullinemia symptoms do not first present until late childhood or even adulthood. This later-presenting variant of type I citrullinemia is milder, but less common, than in the early onset variant of the condition. Those who first experience type I citrullinemia after infancy suffer from symptoms such as balance problems, severe headaches, vision problems, and extreme fatigue.
Type II citrullinemia symptoms, which can first present in adulthood, affect the nervous system, can be life-threatening, and include memory loss, aberrant behavior, confusion, and even coma. Interestingly, these symptoms can be induced or exacerbated by certain drugs, bacterial infection, and even some surgical procedures. Like the type I form, the type II form is caused by excess ammonia in the blood.