THAP1 and spasmodic dystonia: THAP1 binds to the core promoter of TorsinA, and wild-type THAP1 represses the expression of TorsinA, whereas Dyt6-associated mutant THAP1 results in decreased repression of TorsinA and increased expression.15–21 Recent studies have emphasized the fact that THAP1 mutations occur frequently with oromandibular and laryngeal dystonia, but focal, segmental, and generalized dystonia have all been described.