TOR1A and early-onset generalized limb-onset dystonia: As previously mentioned, human genetic analyses uncovered that torsinA (D216H), when carried in trans to the torsinA (ΔE) allele was “protective”; torsinA (D216H) was found at a higher frequency in non-manifesting DYT1 carriers and decreased in affected DYT1 dystonia patients (Fig. 2B) [53].