Argininemia is an autosomal recessive error of metabolism that is classified as a urea cycle disorder. This disease is caused by a deficiency or a defect in the cytosol liver type arginase AI enzyme (L-arginine urea-hydrolase). This enzyme controls the final step of the urea cycle, which is necessary to rid the body of the nitrogen generated by metabolism, primarily of amino acids, originating from diet or from endogenous catabolism. Arginase is responsible for the hydrolysis of arginine to ornithine and urea which can then be excreted from the body in urine. If this step of the urea cycle cannot be performed as in the case of arginase deficiency; accumulation of excessive nitrogen in the form of ammonia in the blood (hyperammonemia), as well as arginine in the blood (hyperarginemia) and cerebrospinal fluid will occur. The accumulation of ammonia and arginine are believed to cause neurological problems and other signs and symptoms of arginase deficiency.
In a retrospective analysis of IEMs diagnosed over a 12-year period (1998-2010) in a hospital in Lebanon, Karam et al. (2013) found a single patient diagnosed with Hyperagininemia. The diagnosis was made at 2-months of age.
Korman et al. (2004) diagnosed arginase deficiency in a 3-year-old male child of first-cousin parents.
Grody et al. (1992) explored the molecular pathology for liver arginase deficiency in a cohort that included a Saudi father and his child. In the child, loss of a TaqI cleavage site was identified in a homozygous state. Grody et al. (1992) speculated that this TaqI mutation lies outside exon 8 of the ARG1 gene.