Compound heterozygous polymerase gamma gene mutation in a patient with Alpers disease

Alpers disease is a mitochondrial depletion syndrome characterized by psychomotor retardation, intractable epilepsy, and liver failure. Polymerase gamma (POLG) gene mutations are a known cause of the disease. We describe a case in which a 14-month-old female presented with epilepsia partialis continua evolving into generalized status epilepticus. Treatment with multiple antiepileptic medications and the ketogenic diet eliminated her seizures, but she remained severely encephalopathic. Magnetic resonance imaging showed diffuse atrophy of gray-matter structures. She ultimately developed liver failure and died. Mitochondrial analysis revealed compound heterozygosity for 3 POLG gene mutations, 2 of which were previously unreported.