Management and long-term evolution of a patient with 3-hydroxy-3-methylglutaryl-coenzyme A lyase deficiency

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) lyase deficiency is a rare inborn error of metabolism characterized by recurrent metabolic crises caused by fasting, intercurrent illness and excessive physical exercise. Non ketotic hypoglycemia is normally the cause of primary symptoms but without an immediate treatment the illness can evolve into a worsening metabolic state resembling the Reye’s syndrome that may cause the patient’s death. We report a case with some clinical and therapeutic features not previously described.

Patient with HMG-CoA lyase deficiency whom after diagnosis at 2 years of age was re-admitted 12 years later, after severe metabolic decompensation following consumption of alcohol. Despite a quick correction of hypoglycemia, within the following few hours, the patient fell into a coma. Suspecting intracranial hypertension (ICH), the patient required mechanical ventilation. Although liver cytolysis was minimal, hyperamoniemia reached 1394 μmol/L, returning to normal, a few hours after administering sodium phenylacetate and sodium benzoate, whose use has not been reported in these patients. Brain edema was evidenced in the computed tomography and by the magnetic resonance imaging that determined that the edema was cytotoxic, as quantified with the restriction of diffusion in the apparent diffusion coefficient map. During the recovery of the ICH, we belatedly, detected vasospasm moderate-severe that was treated with nimodipine. Currently, the patient maintains clinical normality.

The alcohol consumption must be avoided in patients with HMG-CoA lyase deficiency. In our patient hyperamoniemia was effectively treated with sodium phenylacetate and sodium benzoate. Magnetic resonance imaging showed and quantified the cytotoxic brain edema. Belatedly, a cerebral vasospasm was an additional mechanism of cerebral injury. None of these observations has been previously reported.