Long-term benefit of GPi-DBS in YY1-related dystonia: a case report

Gabriele-de Vries syndrome (GADEVS) is a rare genetic disorder caused by mutations in the YY1 gene. It often leads to developmental delay, cognitive difficulties, and congenital abnormalities. About half of affected individuals develop movement disorders, including dystonia. Evidence for effective treatment is still limited. We describe a 35-year-old male patient with juvenile-onset generalized dystonia. His symptoms did not improve with medication. Genetic testing showed a previously unreported de-novo YY1 nonsense variant. Because of the progression of symptoms, he underwent bilateral deep brain stimulation of the globus pallidus internus (DBS-GPi). After surgery, his condition improved. His dystonia became less severe, and his gait and speech also improved. The Burke-Fahn-Marsden motor score decreased from 100 to 50, and the disability score decreased from 20 to 14 at six months. Follow-up at four years, after implementing Brainlab software, showed further improvement in Burke-Fahn-Marsden dystonia motor score of 46 and a stable disability score of 14. Adjustments of stimulation parameters helped maintain good control of symptoms. Only one similar case treated with DBS has been reported so far. This case suggests that DBS-GPi may be a useful treatment option for dystonia caused by YY1 mutations.