CAPOS syndrome is a rare genetic neurological disorder which is characterized by abnormalities of the feet, eyes and brain which affect their normal function. These symptoms occur episodically when a fever-related infection is present within the body.[2][3] The name is an acronym for "cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss".[4]

CAPOS syndrome
Other namesCAPOS CAPOS syndrome. Cerebellar ataxia-areflexia-pes cavus-optic atrophy-sensorineural hearing loss syndrome. Cerebellar ataxia - areflexia - pes cavus - optic atrophy - sensorineural hearing loss.[1]
SpecialtyMedical genetics, Ophthalmology, Neurology, Podology
SymptomsMainly cerebellar ataxia, sensorineural hearing loss, and optic nerve atrophy
ComplicationsBlindness, deafness, problems with coordination.
Usual onsetDuring a fever
DurationLifelong
TypesIt is a type of ATP1A3-related disorder
CausesGenetic mutation
PreventionNone
TreatmentSymptom-centred
PrognosisMedium (with treatment), bad (without treatment
Frequencyrare, only 14 cases have been described in medical literature
Deaths-

Signs and symptoms

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Usually, individuals with this condition have cerebellar ataxia, areflexia, high-arched feet, optic nerve wasting/degeneration, sensorineural deafness.[5]

These symptoms have variable onset, but they generally begin episodically after having a fever-causing infection such as the common cold, manifesting mainly as sudden-onset ataxic episodes and encephalopathy. Other triggers include pregnancy and giving birth. Other symptoms that occur during the episodic ataxia includes hypotonia, nystagmus, strabismus, dysarthria, dysphagia, areflexia/hyporeflexia, and temporary deafness. More serious symptoms include loss of consciousness and/or onset of a coma.[5]

These symptoms usually improve alongside the illness that caused the fever.[5]

General frequency of episodes with people suffering from CAPOS syndrome is 1-3.[5]

Complications

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There are various complications associated with the disorder, some of them include vision impairment/blindness due to optic atrophy characteristic of the disorder, deafness due to atrophy of the nerves that aid in hearing, problems with walking due to the ataxia, etc.

Causes

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This condition is caused by autosomal dominant missense mutations in the ATP1A3 gene, in chromosome 19. The mutation is thought to be gain-of-function.[6]

Epidemiology

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According to OMIM,[7] only 14 cases have been described in medical literature.

History

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This condition was first discovered in 1996 by Nicolaides et al. when they described a mother and two siblings (brother and sister) with (summarized) early-onset reoccurring cerebellar ataxia and progressive optic atrophy accompanied by sensorineural deafness.[4]

References

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  1. ^ "Cerebellar ataxia, areflexia, pes cavus, optic atrophy and sensorinural hearing loss". Archived from the original on 2022-05-13. Retrieved 2022-06-30.
  2. ^ "Cerebellar ataxia-areflexia-pes cavus-optic atrophy-sensorineural hearing loss syndrome". www.ebi.ac.uk. Archived from the original on 2022-06-30. Retrieved 2022-06-30.
  3. ^ RESERVED, INSERM US14-- ALL RIGHTS. "Orphanet: Cerebellar ataxia areflexia pes cavus optic atrophy sensorineural hearing loss syndrome". www.orpha.net. Archived from the original on 2019-07-09. Retrieved 2022-06-30.{{cite web}}: CS1 maint: numeric names: authors list (link)
  4. ^ a b Nicolaides, P.; Appleton, R. E.; Fryer, A. (1996-05-01). "Cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss (CAPOS): a new syndrome". Journal of Medical Genetics. 33 (5): 419–421. doi:10.1136/jmg.33.5.419. ISSN 0022-2593. PMC 1050615. PMID 8733056.
  5. ^ a b c d "Cerebellar ataxia, areflexia, pes cavus, optic atrophy and sensorinural hearing loss - About the Disease - Genetic and Rare Diseases Information Center". rarediseases.info.nih.gov. Archived from the original on 2021-04-14. Retrieved 2022-06-30.
  6. ^ Demos, Michelle K.; van Karnebeek, Clara Dm; Ross, Colin Jd; Adam, Shelin; Shen, Yaoqing; Zhan, Shing Hei; Shyr, Casper; Horvath, Gabriella; Suri, Mohnish; Fryer, Alan; Jones, Steven Jm (2014-01-28). "A novel recurrent mutation in ATP1A3 causes CAPOS syndrome". Orphanet Journal of Rare Diseases. 9: 15. doi:10.1186/1750-1172-9-15. ISSN 1750-1172. PMC 3937150. PMID 24468074.
  7. ^ "OMIM Entry - # 601338 - Cerebellar ataxia, areflexia, pes cavus, optic atrophy, and sensorineural hearing loss; CAPOS". omim.org. Archived from the original on 2022-01-19. Retrieved 2022-06-30.