Increasing Ureagenesis in Inborn Errors of Metabolism With N-Carbamylglutamate

Inclusion Criteria: * Age range: males or females, ages 3 years - 70 years * Condition(s): N-acetylglutamate synthetase deficiency, propionic acidemia, methylmalonic acidemia, carbamylphosphate synthase deficiency, ornithine transcarbamylase deficiency and the syndrome of hyperammonemia, hypoglycemia and hyperinsulinemia. * In addition, healthy volunteers will be studied (ages 18 years - 50 years). Exclusion Criteria: * Acutely ill on day of study (fever, evidence of hyperammonemia - ataxia, worsening obtundation, focal neurologic signs, seizures, increased intracranial pressure, vomiting, signs of acute respiratory or enteric illness, headache, confusion, disorientation, acute personality change). * Girls 11 years of age must have a negative urine/serum pregnancy test within 1 week prior to testing unless having a menstrual period during week of test * Lactating females * Hyperammonemia probably refractory to N-carbamylglutamate: other urea cycle disorders (UCD), lysinuric protein intolerance, mitochondrial disorders, congenital lactic acidemia, fatty acid oxidation defects or primary liver disease. * Amount of blood necessary for study exceeds safe limits. * Any investigational drug use within 30 days prior to enrollment. * Parents/guardians or subjects who, in the opinion of the PI, may be non-compliant with study schedules or procedures. * Subjects who do not meet all the enrollment criteria may not be enrolled. Any violations of these criteria will be reported in acco…