ATXN1 and spinocerebellar ataxia type 1: Spinocerebellar ataxia type 1 (SCA1) is a fatal, dominantly inherited neurodegenerative disorder caused by CAG trinucleotide expansion in exon 8 of the ATXN1 gene which causes the formation of an expanded polyglutamine (polyQ) repeat within the ataxin-1 protein, leading to the premature degeneration of cerebellar Purkinje cells (Sheeler et al., 2024).