ATXN1 and autosomal dominant cerebellar ataxia: Among the six SP SCA-ATXN1 patients (SARA ranging from 8 to 29), visual acuity reduction and dyschromatopsia were detected in only two (SP1 and SP2, 4 of 12 eyes, 33.3%); in the remaining four SP patients (8 of 12 eyes, 66.6%), no visual symptoms (normal visual acuity and chromatic perception) were found.