In addition to HD, there are six types of spinocerebellar ataxias (SCA1, SCA2, SCA3, SCA6, SCA7, and SCA17), dentatorubral-pallidoluysian atrophy (DRPLA), and spinal and bulbar muscular atrophy (SBMA)/Kennedy’s disease [146]. The gene discussed is TBP; the disease is Kennedy disease.