16-year-old male with a personal history of adenoidectomy at age 4, factor VII and X deficiency (detected at age 4), unconjugated hyperbilirubinaemia (detected at age 15). Maternal uncle, 37 years old, mentally retarded, died of status convulsus. He was admitted for asthenia, hypotension (100/70 mmHg), anorexia and dizziness coinciding with a decrease in the dose of dexamethasone (Dacortin 60 mg/day) prescribed for peripheral facial paralysis. On suspicion of adrenal insufficiency, he was admitted to the hospital ward. A progressive tendency to sleep, slight disorientation and hallucinations with hyperbilirubinaemia and hyperammonaemia were detected, and he was admitted to the Intensive Care Unit. On arrival he presented the following findings: height 1.85 m, weight 75 kg, blood pressure 130/70 mmHg; heart rate 100 bpm; temperature 36.5o, O2 saturation 100%; conscious but disoriented; jaundiced; rest of examination normal.
CBC on admission: Hb 16 g/dl (13-17.4), leukocytes 10,800 mil/mm3 (4-11), platelets 196.000 mil/mm3 (150-400), fibrinogen 287 mg/dL (200-450), total bilirubin 7.1 mgr/dL (0-0.3), direct bilirubin 0.47 mgr/dL (0.3-1.9), AST 50 IU/L (10-40), ALT 169 IU/L (10-40), GGT 16 IU/L (5-40), ammonia 424 mgr/dL (15-45), LDH 310 IU/L (210-420). Glucose 118 mg/dL (69-100), urea 0.17g/L (0.1-0.7), creatinine 0.7 mg/dL (0.5-1), Na 145 mEq/L (132-145), K 3.5 mEq/L (3.1-5.1), Ca 9.1 mEq/L (8.5-10.2), Mg 1.7 mEq/L (1.7-2.2), CO3H 25.78 mEq/L (21-29). The following imaging tests were performed: CT scan of the brain with no notable findings and good differentiation of white and grey matter. Abdominal ultrasound: no sign of thrombosis, homogeneous liver without alterations, kidneys and spleen normal. Abdominal Doppler ultrasound: no alterations in liver, spleen, bladder or kidneys. No ascites, masses or thrombosis. Hepatic artery and splenic vein normal.
At 24 h of admission, ammonia elevation up to 602 mg/dL and prothrombin activity 44% (75-130) (control of 3 months before Act. Pr. 45%). The following day, gradual decrease in ammonia to 67 mg/dL with an increase in BT to 10.3 mgr/dL and BD 0.3 mgr/dL and 24 hours later, intense psychomotor agitation, followed by coma with GCS 7. Ammonia at this time was 575 mg/dL, BT 12.7 mg/dL and BD 0.3 mg/dL. Eight hours later, coma crisis and ammonia of 1,723 mg/dL, at which time we started empirical treatment on suspicion of a urea metabolism disorder, with Benzoate Na 12 g in 30 min and 15 g/24h pc, Carbaglu 1.5 g/6h IV, L carnitine 3 mg every 5 h IV, plasmapheresis and continuous venovenous haemodiafiltration. Twelve hours later we achieved a decrease in BT to 5.4 mg/dL but ammonia rose to 4,535 mg/dL, dropping to 4,004 mg/dL 12 hours later. At this time the patient presented CT scan with signs of cerebral oedema, neurological examination and transcranial Doppler compatible with encephalic death, confirmed by brain scintigraphy. Necropsy was refused, but a postmortem liver biopsy was performed, which showed liver with preserved architecture, ischaemic centrolobulillar necrosis and changes suggestive of metabolic pathology. Subsequent blood and urine tests (at the reference centre) showed ornithine transcarbamylase deficiency. The family study identified the mother as a carrier and one of the siblings and a maternal aunt as affected.

