CLIC5 and cerebellar ataxia: Precise genetic diagnosis remains challenging.<h4>Methods</h4>The aim of this study was to use a whole-exome sequencing approach to study a large, highly consanguineous Italian family in order to identify a new gene correlated with pure cerebellar ataxia.<h4>Results</h4>Sequencing excluded the presence of mutations in known-related genes but revealed a homozygous missense variant in CLIC5; however in vivo analysis of a CLIC5 KO mouse model showed vestibular dysfunction without cerebellar involvement, suggesting that CLIC5 is not directly involved in pure cerebellar ataxia onset.