C9orf72 and juvenile Huntington disease: In addition, some cases of catatonia with genetic abnormalities have been described in neurodegenerative disorders such as C9orf72, associated with frontotemporal dementia, and in Huntington’s disease, reinforcing the importance of looking for genetic abnormalities also in neurodegenerative disorders in line with the known associated vulnerability between neurodevelopmental and neurodegenerative disorders [164].