The picture becomes even more complex when considering that dysregulated IP3-dependent Ca2+ release from the ER has not only been implicated in ITPR1-related ataxias, but also a range of other neurodegenerative diseases including the autosomal dominant polyQ-expansion ataxias SCA23,4 and SCA35, Huntingtons disease2,43, and Alzheimers disease44,45. Here, ITPR1 is linked to spinocerebellar ataxia type 23.