Case series of Arginase 1 deficiency: Expanding the spectrum in hyperargininemia.

BACKGROUND Arginase-1 deficiency is a rare autosomal recessively inherited disorder of the urea cycle. In this study, we describe the clinical and molecular details of 6 patients who were diagnosed with argininemia, and we describe the 2 patients with hyperargininemia who carried 2 novel variations of the Arginase-1 gene. METHOD The clinical and demographic characteristics of the patients with were retrospectively evaluated. RESULTS The ages of the 6 patients ranged from 1 day to 20 years, and each patient had consanguinity between their parents. Neuromotor retardation and spastic paraparesis were found in all patients except 1 who was diagnosed prenatally. Hyperargininemia was present in all patients. Urinary orotic acid excretion was increased in 4 out of the 6 patients. The diagnosis was confirmed by genetic analysis in all the patients. Elevated liver enzymes were detected in 3 of the patients, and blood urea nitrogen levels were normal in each of the 6 patients. CONCLUSION In this study, we describe the 2 patients with hyperargininemia who carried 2 novel variations of the ARG1 gene. Also, we present a patient with normal neurodevelopment who was diagnosed prenatally and treated at an early stage of the disease.