Cerebellar Ataxia with Neuropathy and Vestibular Areflexia Syndrome (CANVAS) is an

autosomal recessive In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...

late-onset heredodegenerative multisystem neurological disease. The symptoms include poor balance and difficulty walking. Chronic cough and difficulty swallowing may also be present. Clinical findings include

ataxia Ataxia is a neurological sign consisting of lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and abnormalities in eye movements. Ataxia is a clinical manifestation indicating dysfunction of ...

sensory neuropathy Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland, or or ...

, and absence of the

vestibulo–ocular reflex The vestibulo-ocular reflex (VOR) is a reflex acting to stabilize gaze during head movement, with eye movement due to activation of the vestibular system. The reflex acts to stabilize images on the retinas of the eye during head movement. Gaze ...

. The syndrome was initially described in 2004. In 2019, the cause was identified as biallelic pentanucleotide expansion in the

RFC1 Replication factor C subunit 1 is a protein that in humans is encoded by the ''RFC1'' gene. Function The protein encoded by this gene is the large subunit of replication factor C, which is a five subunit DNA polymerase accessory protein. Replic ...

gene.

Epidemiology

The

prevalence In epidemiology, prevalence is the proportion of a particular population found to be affected by a medical condition (typically a disease or a risk factor such as smoking or seatbelt use) at a specific time. It is derived by comparing the number o ...

of the disease is currently unknown, largely owing to its recent description and delineation from other forms of

autosomal recessive cerebellar ataxia Autosomal recessive cerebellar ataxia () describes a heterogeneous group of rare genetic disorders with an autosomal recessive inheritance pattern and a clinical phenotype involving cerebellar ataxia. It may refer to: * Autosomal recessive cereb ...

Prognosis and treatment

Specific treatment is lacking. A multidisciplinary approach to supportive care is recommended. The progression is typically slow, with 55% of patients needing

mobility aids A mobility aid is a device designed to assist walking or otherwise improve the mobility of people with a mobility impairment. There are various walking aids which can help people with impaired ability to walk, and wheelchairs or mobility scoote ...

10 years after onset, and 25% needing a

wheelchair A wheelchair is a chair with wheels, used when walking is difficult or impossible due to illness, injury, problems related to old age, or disability. These can include spinal cord injuries ( paraplegia, hemiplegia, and quadriplegia), cerebr ...

after 15 years.{{Cite journal, last1=Cortese, first1=Andrea, last2=Tozza, first2=Stefano, last3=Yau, first3=Wai Yan, last4=Rossi, first4=Salvatore, last5=Beecroft, first5=Sarah J, last6=Jaunmuktane, first6=Zane, last7=Dyer, first7=Zoe, last8=Ravenscroft, first8=Gianina, last9=Lamont, first9=Phillipa J, last10=Mossman, first10=Stuart, last11=Chancellor, first11=Andrew, date=2020-02-10, title=Cerebellar ataxia, neuropathy, vestibular areflexia syndrome due to RFC1 repeat expansion, journal=Brain, volume=143, issue=2, pages=480–490, doi=10.1093/brain/awz418, issn=0006-8950, pmc=7009469, pmid=32040566

References

Systemic atrophies primarily affecting the central nervous system