This mutation belongs to a class of non-coding repeat expansions that cause other spinocerebellar ataxia disorders (SCA8, SCA12, SCA31, SCA36) as well as amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD), myotonic dystrophy types 1 (DM1) and 2 (DM2), fragile X-associated tremor/ataxia syndrome (FXTAS), Friedreich’s ataxia (FA), and Huntington’s Disease Like 2 (HDL2). The gene discussed is PPP2R2B; the disease is myotonic dystrophy type 1.