Short-Term Outcome of N-Carbamylglutamate in the Treatment of Acute Hyperammonemia

Inclusion Criteria o Aged older than 1 week with an established diagnosis of CPSD or OTCD (as follows): * Diagnosed with late-onset CPSD confirmed by detection of pathogenic mutation(s), and/or decreased (\<20% of control) CPS enzyme activity in liver OR * Diagnosed with late-onset OTCD by detection of pathogenic OTC mutation, OR decreased (\<20% of control) OTC enzyme activity in liver OR elevated urinary orotate (greater than 20 µM/mM) following allopurinol loading with the absence of argininosuccinic acid AND: Subject or subject's first-degree relative had plasma ammonia level ≥100 μmol/L \>1 week of age OR o An established diagnosis of PA or MMA (as follows): \- Diagnosed with PA by semi-quantitative urine organic acid analysis, defined as the presence of elevated Methylcitric acid and normal methylmalonic acid levels and no evidence of biotin related disorders in the organic acid analysis OR \- Diagnosed with MMA by semi-quantitative urine organic acid analysis, defined as an elevation of methylmalonic acid and no evidence of vitamin B12 dependent disorder on plasma amino acid analysis (B12 dependency is defined by documented B12 responsiveness) AND: Subject or subject's first-degree relative had plasma ammonia level at any time ≥100 μmol/L * Able to receive medications orally, by nasogastric (NG)-tube or by gastric (G)-tube * No concomitant illness which would preclude safe participation as judged by the investigator * If post-menarcheal must have a negative p…