Studies in genetic mapping and genome-wide association have identified specific genetic loci associated with SCA, including B-cell lymphoma/leukemia 11A (BCL11A), an Xmn1 variant located upstream of the hemoglobin subunit gamma 1 (HBG1), and the HBS1L-MYB intergenic region. This evidence concerns the gene HBG1 and autosomal dominant cerebellar ataxia.