Spasmodic cough preceding CANVAS phenotype in a family with biallelic repeat expansions in RFC1.

Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is a late-onset, multisystem ataxia that remained only clinically defined, until recently, when the discovery of biallelic repeat expansion in the RFC1 gene allowed the genetic link. We describe the first Portuguese familial CANVAS harboring the pathogenic RFC1 expansion. Detail clinical features and course of four affected members are provided. Phenotype characterizations are important as the novel RFC1 mutation is expected to be a major cause of idiopathic late-onset ataxia.