These include eight subtypes of spinocerebellar ataxia (SCA), SCA1, SCA2, SCA3, SCA6, SCA7, SCA12, and SCA17, and a novel SCA subtype caused by intragenic CAG repeat expansion in THAP11, in addition to dentatorubral-pallidoluysian atrophy (DRPLA), Huntington disease-like 2, and spinal and bulbar muscular atrophy (Robitaille et al., 1997; Stoyas and La Spada, 2018; Tan et al., 2023). This evidence concerns the gene PPP2R2B and dentatorubral-pallidoluysian atrophy.