Argininemia

Arginase deficiency, also called argininemia or hyperargininemia, is a rare inherited metabolic disorder of the urea cycle, the liver pathway that turns waste nitrogen from protein into urea. It is caused by variants in the ARG1 gene, which carries the instructions for the enzyme arginase, so the last step of the cycle fails and arginine and ammonia build up in the blood. It is inherited in an autosomal recessive pattern and is estimated to occur once in every 300,000 to 1,000,000 individuals. Signs usually appear by about age 3, most often as stiffness of the legs from spasticity, slowed growth, developmental delay, intellectual disability, seizures, tremor and unsteady balance, and milder cases may not show until later in life. The nervous system is especially sensitive to the excess ammonia. This entry records what the sources state and is not medical advice.