Browsing Pathways

Argininosuccinic Aciduria, (Argininosuccinase Deficiency, Argininosuccinate Lyase Deficiency, ASL Deficiency) is an autosomal recessive disorder caused by a mutation in the ASL gene which codes for argininosuccinate lyase. It results in accumulation of citrulline, arginosuccinic acid, L-arginine, and L-glutamic acid in plasma as well as ammonia in blood. Infants are lethargic and unwilling to eat. They may develop seizures, coma, and failure to thrive as toxic ammonia accumulates.

CCarbamoyl Phosphate Synthetase Deficiency, also called hyperammonemia due to carbamoyl phosphate synthetase 1 deficiency, is a rare inborn error of metabolism (IEM) and autosomal recessive disorder of the urea cycle caused by a defective CPS1 gene. The CPS1 gene codes for the protein carbamoyl phosphate synthetase I, which plays a role in the urea cycle. This disorder is characterized by a large accumulation of ammonia in the blood. Symptoms of the disorder include unusual movements, seizures, unusual sleeping or coma. Treatment with citrulline or arginine, which maintains a regular rate of protein creation. It is estimated that carbamoyl phosphate synthetase deficiency affects 1 in 800,000 individuals in Japan.

Citrullinemia Type 1, also called argininosuccinate synthetase deficiency, argininosuccinic acid synthetase deficiency or ASS deficiency, is a rare inborn error of metabolism (IEM) and autosomal recessive disorder of the urea cycle caused by a deficiency of argininosuccinate synthetase. Argininosuccinate synthetase is an important enzyme in the process of removing nitrogen from the body. This disorder is characterized by a large accumulation of ammonia in the blood as well as other bodily fluids . Symptoms of the disorder include vomiting, lethargy and intracranial pressure. Treatment with protein restriction and intravenous administration of arginine can help manage symptoms, and diet management throughout the patient’s life can also show improvement. It is estimated that citrullinemia type 1 affects 1 in 57,000 individuals.