TOR1A and infection: In terms of non-genetic factors that might affect the penetrance of TOR1A mutations, one small study has assessed exposure to perinatal adversity, childhood infections, general anaesthesia and trauma in manifesting and non-manifesting carriers as well as non-carriers from a series of 28 families with DYT1-related dystonia by means of a retrospective questionnaire (Martino et al., 2012).