Abstract
At the time of writing this Helix, the ranks of spinocerebellar ataxias (SCAs) have swelled to 48 genes or genetic loci mirroring a similar development in other categories of movement disorders such as dystonia or spastic paraplegia.(1) Although SCAs have a worldwide distribution, some of the recently identified SCAs have shown regional aggregation. SCA42 is one such example. It is caused by mutation in CACNA1G and was initially described only in French and Japanese families. Now, Ngo et al.(2) describe CACNA1G mutations in 3 pedigrees from Italy, Eastern Europe, and Yemen. Interestingly, all SCA42 families described so far share the same mutation suggesting that the mutation (hg19:chr17:48694921G>A, p.Arg1715His) is a mutational hot spot.
