Case | Sex | Age at presentation | Presenting symptoms | Ammonia concentration | Other relevant abnormal test results at presentation | Treatment of presenting episode | Subsequent hyperammonemic episodes before treatment with carbamylglutatmate |
---|---|---|---|---|---|---|---|
1 | Female | 3 days | Apnea, convulsions, depressed consciousness, encephalopathy, lethargy, metabolic acidosis, oliguria, poor feeding/sucking, seizures, tachypnea, and unresponsiveness | Presenting: 1257 µmol/L (reference range < 77 µmol/L) Peak: 1500 µmol/L. During the presenting episode, hyperammonemia (> 100 µmol/L) was present for 6 days. | Glutamine (2132 µmol/L; ref: 246–984), urine orotic acid (14.8 mmol/mol creatinine; ref: 2.6–5.8) | Intravenous (IV) Sodium phenylbutyrate and sodium benzoate, hemodialysis followed by continuous veno-venous hemofiltration (CVVH), IV arginine, parenteral nutrition (TPN) with low protein and age-appropriate calories | None |
2 | Female | 6 days | Abdominal distension, breathing difficulty, confusion, dehydration, drowsiness, encephalopathy, grunting, hypothermia, hypotonia, poor feeding, respiratory distress, and vomiting; Consanguinity | Presenting: >700 µmol/L (ref < 100 µmol/L) Peak concentration and number of days with elevated ammonia not available | Glutamine (793 µmol/L; ref: 229–684) | Hemodialysis for three days with two temporary discontinuations due to coagulated filters, IV sodium phenylacetate, and sodium benzoate. | Four additional episodes of hyperammonemia, with a total of three days with ammonia > 100 µmol/L |
3a | Male | 38 years | Asterixis, ataxia, behavioral problems, combativeness, confusion, depressed consciousness, drowsiness, encephalopathy, headaches, irritability, nausea, spasticity, and vomiting | Presenting: 434 µmol/L (ref: 15–50 µmol/L) at presentation. Peak concentration not available. During the presenting episode, hyperammonemia (> 100 µmol/L) was present for 8 days. | Glutamine (1062 µmol/L; ref: 104–750) | Sodium phenylbutyrate and citrulline (50 mg/kg/day) | Four additional episodes of hyperammonemia, but the concentration did not exceed 100 µmol/L |
4 | Male | 25 months | Altered mental status, breathing difficulty, developmental delay, disconjugate gaze, encephalopathy, hyperpnea, irritability, metabolic acidosis, pallor, poor capillary refill, poor feeding, and vomiting | Presenting: 120 µmol/L (ref: 21–50 µmol/L) Peak: 185 µmol/L. During the presenting episode, hyperammonemia (> 100 µmol/L) was present for 2 days. | Glutamine (1448 µmol/L; ref: 410–700), citrulline (9 µmol/L; ref: 10–60), urine orotic acid (7.3 mmol/mol creatinine; ref: 0.7–5.1), urine ketones (3+), urine protein (1+) | Sodium phenylbutyrate, 10% dextrose water and ½ normal saline at 1.5 x maintenance (D10W ½ NS at 1.5 x M), and IV citrulline (170 mg/kg/day). | Four additional episodes of hyperammonemia, but the concentration did not exceed 100 µmol/L |
5 | Female | 14 years | Abdominal pain, headaches, hypertonia, lethargy, nausea, protein aversion, and vomiting; family history of a sister diagnosed with NAGS deficiency as an infant. | Presenting: 95 µmol/L (ref: 11–35 µmol/L) Peak: 223 µmol/L. During the presenting episode, hyperammonemia (> 100 µmol/L) was present for 2 days. | Not available | Sodium phenylbutyrate and IV dextrose 12.5, ½ NS at two times maintenance | Several documented episodes but details are not available |
6b | Female | 10 years | Ataxia, encephalopathy, nausea, protein aversion, vomiting, dizziness, and syncope; family history of a cousin with seizures. | Presenting: 203 µmol/L (ref: 9–33 µmol/L) Peak: 293 µmol/L. During the presenting episode, hyperammonemia (> 100 µmol/L) was present for 2 days. | Glutamine (868 µmol/L, ref: 49–736), urine orotic acid (4.1 mmol/mol creatinine, ref: 0.2–1.2), ketones (4+) | Sodium benzoate, sodium phenylacetate, and IV arginine | 18 additional episodes of hyperammonemia, with a total of 30 days with ammonia greater than 100 µmol/L |
7 | Male | 2 years | Abdominal pain, confusion, feeding intolerance, poor feeding, seizures, and vomiting. | Details not available in chart | Glutamine (970 µmol/L; ref: 205–756), citrulline (63 µmol/L, ref: 12–55) | Sodium phenylbutyrate, sodium benzoate, and IV arginine | 35 additional episodes of hyperammonemia, with a total of 19 days with ammonia > 100 µmol/L |