Citrullinemia is a condition with multiple forms. Each form of citrullinemia has different treatments and outcomes. Citrullinemia is an inherited disorder that causes ammonia and other toxic substances to build up in the blood.
Citrullinemia type I (CIT-I) is also known as classic citrullinemia. It usually becomes evident in the first few days of life. Infants seem healthy at birth but quickly develop symptoms within a few days of life when high levels of ammonia build up in their blood. Symptoms progress and may include lack of energy, poor feeding, vomiting, seizures, poor muscle tone, coma, and even death. Less commonly, a milder form of CIT-I can develop later in childhood or adulthood. This later-onset form is associated with intense headaches, partial loss of vision, problems with balance and muscle coordination (ataxia), and lethargy. A few individuals with CIT-I never experience signs and symptoms of the disorder.
This condition is also known as: argininiosuccinate synthetase deficiency, arginininosuccinic acid synthetase deficiency, AS deficiency, ASS deficiency, citrullinuria, CTLN1, citrullinemia.
To learn more about Type I Citrullinemia, visit Screening, Technology, and Research in Genetics (STAR-G): Citrullinemia and Baby's First Test: Citrullinemia, Type I. Please see Medically Prescribed Formula for information about medically prescribed formula and pharmacologic interventions for inborn errors of metabolism. Visit Board Certified Metabolic Providers (PDF: 2 pages/204KB) for a listing of medical specialists and clinic contact information.
Citrullinemia, type II (CIT-II) is a condition in which the body is unable to make citrin. Citrin is a protein that helps move substances within the cells. These substances are important for breaking down sugars, producing proteins and nucleotides, and allowing for the normal function of the liver. CIT-II is considered an amino acid condition because people with this condition are unable to transport certain amino acids into mitochondria, the energy-production centers of the cell. CIT-II is also called a urea cycle condition. Signs of CIT-II can begin in infancy, adolescence, and adulthood. In babies the signs of CIT-II usually begin between one and five months of age. CIT-II mainly affects the nervous system, causing confusion, restlessness, memory loss, irritability, seizures, and coma. Treatment may include a special diet, medication, or supplements.
This condition is also known as: citrullinuria, citrin deficiency, CTLN II, neonatal intrahepatic cholestasis caused by citrin deficiency (neonatal form only), NICCD (neonatal form only).
For more information about Citrullinemia, Type II, visit Baby's First Test: Citrullinemia, Type II. Please see Medically Prescribed Formula for information about medically prescribed formula and pharmacologic interventions for inborn errors of metabolism. Visit Board Certified Metabolic Providers (PDF: 2 pages/204KB) for a listing of medical specialists and clinic contact information.