The team at the Sheffield Ataxia Centre, led by Prof Marios Hadjivassiliou, has been investigating whether faulty genes called RFC1 seen in a condition called CANVAS (cerebellar ataxia, neuropathy and vestibular areflexia syndrome) are present in people with ataxia of unknown cause. The RFC1 gene is needed for DNA repair in cells. A fault involving an expansion of the building blocks in the RFC1 protein, in a repeating pattern, leads to symptoms such as ataxia, cognitive decline, chronic cough, involuntary movement and muscle twitching. Â
The team found that in 38 participants diagnosed with cerebellar ataxia and sensory ganglionopathy (SG) – loss of sensations such as touch and reflexes – 71% of them had faulty RFC1. However, in 54 participants with idiopathic sporadic ataxia without SG, none possessed the faulty RFC1 gene. Â
Importantly, the study has shown that the presence of sensory ganglionopathy in people with ataxia is a good indicator that someone may have CANVAS.  This finding is helpful in informing clinicians as to whether a test for RFC1 is needed. Since CANVAS with faulty RFC1 genes is now thought to be one of the most common recessive ataxias after Friedreich’s Ataxia and Spastic Paraplegia Type-7, more efficient screening methods for the presence of faulty RFC1 are important for diagnostic progress. Â
