This “loss-of-function” mechanism was undeniably proven in the case of spinocerebellar ataxia type 1, caused by expansion of a glutamine-encoding repeat in ataxin 1, in which the amount of nuclear deposits of mutant ataxin-1 was shown to inversely correlate with the severity of the disease [103]. The gene discussed is ATXN1; the disease is spinocerebellar ataxia type 1.