Abbreviations
FP-CIT 2b-carbomethoxy-3b-(4-iodophenyl)-N-(3-fluoropropyl) nortropane
GFAP Glial fibrillary acidic protein
MRI Magnetic resonance imaging
PD Parkinson’s disease
PET Positron emission tomography (PET)
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Acknowledgements
Not applicable.

Authors’ contributions
JP, JK, K-YK made the clinical diagnosis, and clinical management decisions. They supervised the drafting of the manuscript. JP drafted the first manuscript and reviewed the literature. S-TP, JK, K-YK revised it critically. JK supported making the diagnosis and clinical management decisions as the specialists of genetic study and performed genetic analysis of GFAP. K-YK supervised the drafting of the manuscript and revised it critically. All authors have read and approved the final manuscript.

Funding
This work was supported by the Soonchunhyang University Research Fund to Kyum-Yil Kwon. The funding body played no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript.

Availability of data and materials
The dataset supporting the conclusions of this article is included within the article.

Ethics approval and consent to participate
Not applicable.

Consent for publication
The subject gave written informed consent for the publication of any associated data and accompanying images.

Competing interests
Kyum-Yil Kwon is an associate editor of BMC Neurology.
Other authors declare that they have no competing interests.