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In Reply Finsterer and Zarrouk-Mahjoub list movement disorders not mentioned in our article1; however, we would question their relevance. The article they referenced by Gimelli et al2 reports 4 cases of inherited Tourette syndrome. Although the protein localizes to mitochondria, no evidence of mitochondrial dysfunction suggestive of an oxidative phosphorylation defect is provided; indeed, we are not aware of any definite Tourette syndrome cases related to primary mitochondrial disorders. The other article they referenced by van Rossum and ten Houten3 describes a patient with the m.3243A>G mutation and tics that “consisted of blinking of the eyes, movement [of] the head and the rubbing of the chin along the shoulder,” features suggesting seizure semiology rather than a tic disorder, particularly given the high prevalence of epilepsy in this genotype4 and that the patient had documented epilepsy.
Martikainen MH, Burn DJ, Turnbull DM. Spectrum of Movement Disorders in Mitochondrial Disorders–Reply. JAMA Neurol. 2016;73(10):1254-1255. doi:10.1001/jamaneurol.2016.2578