Anthony Quinn, PhD, President and CEO of Aeglea BioTherapeutics, provides an overview of Arginase 1 (ARG1) deficiency. 

As Dr. Quinn explains, ARG1 deficiency is a rare genetic disorder characterized by complete or partial lack of the enzyme arginase in the liver and red blood cells. Arginase is one of six enzymes that play a role in the urea cycle. The lack of the arginase enzyme results in hyperargininemia in the blood and cerebrospinal fluid, and can lead to hyperammonemia in the blood as well. Children most often experience spasticity (especially in the lower limbs) but may also experience seizures, short stature, and intellectual disability. 



The spasticity associated with ARG1 deficiency often leads to these patients being misdiagnosed with cerebral palsy or hereditary spastic paraparesis. As Dr. Quinn mentions, education and awareness about ARG1 deficiency would prevent misdiagnosis, which is crucial as the disease is progressive.

To learn more about ARG1 deficiency and other rare metabolic disorders, visit