How is argininemia classified?
Argininemia can be classified as a urea cycle disorder or an amino acid disorder. People with this disorder have problems with an enzyme called arginase I. This enzyme is missing, deficient, or damaged. The arginase I enzyme has a job. It is part of the urea cycle. This cycle is series of biochemical reactions that occur in the body to help to break down (metabolize) and then remove excess nitrogen from the body. Nitrogen is obtained from the diet and is a normal waste product of the metabolism of protein. Nitrogen is broken down into a compound called urea that is excreted from the body in the urine. People with argininemia cannot properly break down the arginine, which is a step in the urea cycle. Because they cannot break down arginine and cannot completely convert nitrogen into urea, arginine and nitrogen (in the form of ammonia) build up in the body. Arginine, which is found in elevated levels in people with argininemia, is an amino acid. Amino acids are chemical 'building blocks' the body uses to produce certain proteins that are required for proper growth and development. Therefore, argininemia is both a urea cycle disorder and an amino acid disorder.
Wong D, Cederbaum S, Crombez EA. Arginase Deficiency. GeneReviews website. https://www.ncbi.nlm.nih.gov/books/NBK1159
Arginase deficiency. The Genetics and Rare Diseases Information Center website. https://rarediseases.info.nih.gov/diseases/5840/resources