Early Diagnosis of CAPOS Syndrome Before Acute-Onset Ataxia-Review of the Literature and a New Family

Pediatr Neurol. 2017 Jun;71:60-64. doi: 10.1016/j.pediatrneurol.2017.01.009. Epub 2017 Jan 25.


Background: CAPOS syndrome (cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss) is a rare disease that has been reported in 22 patients so far. In all cases, the mutation c.2452G>A (p.Glu818Lys) in the ATP1A3 gene was identified. Patients typically present at an early age with an acute-onset fever-induced episode of ataxia frequently associated with encephalopathy and weakness. They usually present one to three episodes. The acute symptoms improve within days, but most patients show slow progression afterward.

Methods: We describe three new patients, a woman and her two sons diagnosed with CAPOS syndrome. A systematic review of literature on previously reported patients was performed.

Results: The first son presented with acute-onset ataxia, encephalopathy, and sensorineural hearing loss, induced by febrile illness. The second one developed generalized areflexia and mild instability without an acute episode. The mother had been previously diagnosed with sensorineural hearing loss and optic nerve atrophy. The c.2452G>A mutation in ATP1A3 was found in all three patients.

Conclusion: Only 25 Individuals with CAPOS syndrome have been reported, including our family. This is the first time a Spanish family has been described. The fact that both siblings were assessed before the first acute-onset episode contributes to the description of early symptoms and signs of the disease, which could aid early diagnosis and management before the onset of acute episodes.

Keywords: ATP1A3 gene; CAPOS syndrome; cerebellar ataxia; optic atrophy; sensorineural hearing loss.

Publication types

  • Case Reports
  • Review
  • Systematic Review

MeSH terms

  • Adult
  • Ataxia / diagnosis
  • Ataxia / genetics
  • Ataxia / physiopathology
  • Cerebellar Ataxia / diagnosis*
  • Cerebellar Ataxia / genetics
  • Cerebellar Ataxia / physiopathology
  • Child
  • Early Diagnosis
  • Family
  • Female
  • Foot Deformities, Congenital / diagnosis*
  • Foot Deformities, Congenital / genetics
  • Foot Deformities, Congenital / physiopathology
  • Hearing Loss, Sensorineural / diagnosis*
  • Hearing Loss, Sensorineural / genetics
  • Hearing Loss, Sensorineural / physiopathology
  • Humans
  • Male
  • Optic Atrophy / diagnosis*
  • Optic Atrophy / genetics
  • Optic Atrophy / physiopathology
  • Reflex, Abnormal / genetics

Supplementary concepts

  • CAPOS syndrome