Two Novel Mutations in the Argininosuccinate Lyase Gene in Iranian Patients and Literature Review

The argininosuccinate lyase (ASL) gene encodes argininosuccinate lyase (ASL), which is one of the six enzymes of the urea cycle that detoxifies blood ammonia. Argininosuccinate lyase deficiency impairs the function of the urea cycle and causes hyperammonemia, neurodevelopmental delay and hepatopathy.
Here we report two patients with argininosuccinate aciduria. They were treated with peritoneal dialysis and scavenger drugs. Molecular genetic testing showed two novel homozygous mutations, c.146T > G (p.Leu49Arg) in exon 3 and c.1144-1G > C in intron 15 of the ASL gene.
This report intends to underline the importance of pediatricians being aware of the existence of a metabolic disease in any ill neonate. Diagnosis of urea cycle disorders is particularly important because of availability of effective treatment options.