Citrullinemia Type 1 (also known as classic citrullinemia) is a rare autosomal recessive urea cycle disorder due to reduced activity of argininosuccinate synthetase 1; characterized by hyperammonemia leading to neurological damage.
An impairment of ASS function can lead to a wide spectrum of phenotypes, from life-threatening neonatal hyperammonemia to a later onset with mild symptoms, and even some asymptomatic patients exhibiting an only biochemical phenotype.The disease is panethnic.
Citrullinemia type 1 (CTLN1) is a urea cycle disorder (UCD) caused by mutations of the ASS1 gene, which is responsible for production of the enzyme argininosuccinate synthetase (ASS), and classically presented as life-threatening hyperammonemia in newborns.
Deficiency of ASS1 shows various clinical manifestations encompassing severely affected patients with fatal neonatal hyperammonemia as well as asymptomatic individuals with only a biochemical phenotype.
We present the results of studies in a neonatal bovine model of citrullinemia, an inborn error of urea-cycle metabolism characterized by deficiency of argininosuccinate synthetase and consequent life-threatening hyperammonemia.