Expanding the global prevalence of spinocerebellar ataxia type 42

Spinocerebellar ataxias (SCAs) are a heterogeneous group of neurodegenerative disorders that involve the degeneration of the cerebellum and brainstem.1 These genetic diseases are characterized by autosomal dominant inheritance with approximately 44 known subtypes. Recently, dominant mutations in the CACNA1G gene, encoding the voltage-gated calcium channel CaV3.1, have been linked to SCA42 in French2 and Japanese3,4 families. SCA42 prevalence elsewhere in the world has yet to be documented. Through a combination of whole-exome sequencing (WES) and linkage analysis, we have identified an SCA42 mutation in patients from 3 additional countries, expanding the worldwide prevalence of this disease.