DYT6 Dystonia: A Neuropathological Study.

BACKGROUND Mutations in the thanatos-associated protein domain containing apoptosis-associated protein 1 gene (THAP1) are responsible for adult-onset isolated dystonia (DYT6). However, no neuropathological studies of genetically proven DYT6 cases have been previously reported. OBJECTIVE We report the first detailed neuropathological investigation carried out on two DYT6 brains. METHODS Genetic screening for THAP1 gene mutations using standard Sanger polymerase chain reaction sequencing identified 2 cases, 1 with a known pathogenic mutation and the other with a novel mutation. A detailed neuropathological assessment of the cases was performed. RESULTS Both DYT6 cases showed no significant neurodegeneration and no specific disease-related pathology. CONCLUSIONS No neuropathological features that could be defined as hallmark features of DYT6 dystonia were identified. Our study supports the notion that in isolated dystonia, there is no significant neurodegeneration or morphological lesions that can be identified using routine methods.