We report an adult patient with levodopa-responsive parkinsonism and known pathogenic GFAP variant. This patient did not have typical symptoms suggestive of Alexander disease. The adult-onset Alexander disease has various clinical features, mainly speech abnormalities, swallowing difficulties, frequent vomiting, lower limb spasticity and ataxia [3]. It can be found incidentally at autopsy or molecularly confirmed cases without a prior history and it is possible that the patient may never develop symptoms related to this genetic diagnosis [4]. It may be reasonable to infer that abnormalities of the brain MRI are mild, and it is difficult for them to develop symptoms, or they may develop for a lengthy time, and become chronic adaptation or compensation. In contrast, the patient showed not only typical parkinsonism, but also good levodopa responsiveness, indicating a clinical diagnosis of PD. Moreover, this was highly supported by FP-CIT PET findings of presynaptic dopaminergic depletion. To the best of our knowledge, a case of Alexander disease, with both typical parkinsonism and striatal dopamine depletion, has not been reported.