Introduction: Mutations in the ATP1A3 gene are associated with a diverse group of neurological phenotypes. The phenotypic spectrum of ATP1A3-related neurological disorders continues to expand.  We report a rare case of an infant with severe neonatal epilepsy and prolonged apnea secondary to a mutation in the ATP1A3 gene.

Observation: A 9-month-old boy born to non-consanguineous parents originated from Algeria. At the age of one day, he presented with eyelid clonies caused by the light. At the age of 1 month, he had generalized tonic and hemi-corporal clonic seizures, staring blankly into space with chewing and unilateral nystagmus. He was treated with levetiracetam, valproic acid, and clonazepam with persistence of seizures and occurrence of paroxysmal episodes of prolonged apneas. At the age of 8 months, he presented with episodes of hemiplegia spontaneously resolved after 24 to 48 hours. At the age of 9 months, he had a prolonged apnea followed by a status epilepticus. Examination showed irritability, poor contact, nystagmus, axial hypotonia, quadripyramidal syndrome, choreic limb movements, facial dysmorphism, and apnea access. Brain MRI showed left hippocampal sclerosis. The EEG showed generalized but asymmetrical electric discharges involving both hemispheres alternately. Metabolic assessment was normal. Vitamin B6 test was ineffective. Total sequencing of the exome revealed a heterozygous mutation at the ATPA13 gene.

Conclusion: The mutation of the ATP1A3 gene must be considered in patients presenting with early onset epilepsy and prolonged episodic apnea even in the absence of alternating hemiplegia. Early diagnosis is important for neurological outcome and genetic counseling.