Previously, using a combination of exome sequencing and copy number variant (CNV) familial triangulation analysis, we identified the same large, homozygous, biallelic tandem duplication of 344,085 base pairs (bp) involving approximately 26,000 bp of intergenic sequence, RYR2’s 5′ UTR/promoter region, and exons 1–4 of RYR2 as a potentially novel genetic basis for recessively inherited, exercise-associated SCA/SUDY in 2, seemingly unrelated, large multigenerational Amish pedigrees (5). Here, RYR2 is linked to autosomal dominant cerebellar ataxia.