Argininemia is classified as one of the urea cycle disorders, where individuals lack the vital enzyme arginase, resulting in elevated levels of arginine in their bloodstream.
Most affected individuals exhibit symptoms between 1 and 3 years of age, although earlier onset cases have been documented. Typical symptoms include poor growth, spasticity (stiff muscles), seizures, and intellectual disability leading to skills regression. Some may also experience microcephaly (small head size), liver cirrhosis, issues with balance and coordination, or episodes of hyperammonemia (high ammonia levels in the blood), which can lead to complications like lethargy or vomiting. Treatment includes adherence to a protein-restricted diet, supplementation of necessary amino acids, and the use of medications to lower the levels of arginine in the blood.
Arigininemia is caused by pathogenic (disease-causing) variants in the ARG1 gene and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition.
Other names for this condition are arginase deficiency disease and hyperargininemia.
Resources:
Genetic and Rare Diseases Information Center
Revised July 2023
