Targeted sequencing of ATP1A3 should be considered in any patient presenting with cerebellar ataxia triggered by febrile illness, or pregnancy and delivery, especially in the presence of sensorineural hearing loss, optic atrophy, pes cavus, or early childhood history of acute encephalopathic ataxia.
Cerebellar ataxia, areflexia, pes cavus, optic atrophy and sensorineural hearing impairment (CAPOS) is a rare clinically distinct syndrome caused by a single dominant missense mutation, c.2452G>A, p.Glu818Lys, in ATP1A3, encoding the neuron-specific alpha subunit of the Na+/K+-ATPase α3.
Targeted sequencing of the ATP1A3 gene is recommended in children exhibiting paroxysmal, fever-induced ataxia and in adults with a more or less stationary or slowly progressive cerebellar syndrome since childhood accompanied by mixed combinations of areflexia, pes cavus, profound visual impairment, and/or sensorineural hearing loss.