Snapshot A 5-day-old boy is brought to the hospital by his parents due to recurrent seizures and increased work of breathing for the past day. The patient was born via vaginal delivery to a G1P0 mother, who had an uncomplicated labor and uneventful prenatal history. The parents note that the baby has had 4 seizures, involving spasms of the upper and lower limbs, throughout the course of the day. The patient's temperature is 100.1°F (37.8°C), pulse is 190/min, and respirations are 68/min. Lab studies reveal a blood ammonia of 1020 mg/dL. Introduction Overview login to view 2 more bullets ETIOLOGY Pathophysiology login to view 2 more bullets Genetics login to view 1 more bullet Epidemiology Incidence login to view 1 more bullet Demographics login to view 2 more bullets Presentation Symptoms login to view 7 more bullets Physical exam login to view 6 more bullets Studies Blood ammonia level login to view 3 more bullets Differential Arginosuccinate (ASA) lyase deficiency login to view 2 more bullets Ornithin transcarbamylase (OTC) deficiency login to view 3 more bullets Treatment Lifestyle login to view 1 more bullet Medical login to view 3 more bullets Prognosis Severe CNS impairment is likely in patients with neonatal onset Untreated CPS deficiency is likely fatal