TOR1A and Dystonia: While this has been relatively easy for DYT1-dystonia, with TOR1A mutations causing a rather specific phenotype of early-onset primary generalized dystonia with limb involvement, or in DYT11, the form of myoclonus-dystonia (M-D) caused by mutations in the SGCE gene (2), it has become clear that in most other cases, genotype–phenotype correlations are much more variable and complex than initially believed and that genetic classifications do not translate one to one to clinical phenotypes.