Hepatic coma culminating in severe brain damage in a child with a SCN1A mutation

An 11 months old boy, developed liver failure after febrile status epilepticus while being treated with valproic acid for myoclonic epilepsy and recurrent partial and generalized seizures. The diagnosis of Alpers-Huttenlocher disease was considered. A muscle biopsy showed mitochondrial dysfunction. Mitochondrial DNA depletion was ruled out. Sequencing of the polymerase gamma gene (POLG1) did not detect any mutations. Sequencing of the alpha-1 subunit gene of the voltage-gated neuronal sodium channel (SCN1A) revealed a novel, de novo amino acid change p.Val 1637 Glu. This case expands the spectrum of clinical presentations related to mutations in SCN1A. We warn that children with SCN1A mutations may be at risk for developing liver failure following status epilepticus, due to mitochondrial dysfunction.