About the Authors

Katerina Markopoulou

Contributed equally to this work with: Katerina Markopoulou, Bruce A. Chase

amarkopoulou@northshore.org

Affiliation NorthShore University Health System, Evanston, Illinois, United States of America

Bruce A. Chase

Contributed equally to this work with: Katerina Markopoulou, Bruce A. Chase

Affiliation Department of Biology, University of Nebraska at Omaha, Omaha, Nebraska, United States of America

Piotr Robowski

Affiliations Department of Neurological and Psychiatric Nursing, Medical University of Gdańsk, Gdańsk, Poland, Department of Neurology, St. Adalbert Hospital, Copernicus PL Sp. z o.o, Gdańsk, Poland

Audrey Strongosky

Affiliation Department of Neuroscience, Mayo Clinic Jacksonville, Jacksonville, Florida, United States of America

Ewa Narożańska

Affiliations Department of Neurological and Psychiatric Nursing, Medical University of Gdańsk, Gdańsk, Poland, Department of Neurology, St. Adalbert Hospital, Copernicus PL Sp. z o.o, Gdańsk, Poland

Emilia J. Sitek

Affiliations Department of Neurological and Psychiatric Nursing, Medical University of Gdańsk, Gdańsk, Poland, Department of Neurology, St. Adalbert Hospital, Copernicus PL Sp. z o.o, Gdańsk, Poland

Mariusz Berdynski

Affiliation Department of Neurodegenerative Disorders, Mossakowski Medical Research Center, Polish Academy of Sciences, Warsaw, Poland

Maria Barcikowska

Affiliation Department of Neurodegenerative Disorders, Mossakowski Medical Research Center, Polish Academy of Sciences, Warsaw, Poland

Matt C. Baker

Affiliation Department of Neuroscience, Mayo Clinic Jacksonville, Jacksonville, Florida, United States of America

Rosa Rademakers

Affiliation Department of Neuroscience, Mayo Clinic Jacksonville, Jacksonville, Florida, United States of America

Jarosław Sławek

Affiliations Department of Neurological and Psychiatric Nursing, Medical University of Gdańsk, Gdańsk, Poland, Department of Neurology, St. Adalbert Hospital, Copernicus PL Sp. z o.o, Gdańsk, Poland

Christine Klein

Affiliation Institute of Neurogenetics, University of Lübeck, Lübeck, Germany

Katja Hückelheim

Affiliations Institute of Neurogenetics, University of Lübeck, Lübeck, Germany, Department of Psychiatry and Psychotherapy, University of Lübeck, Lübeck, Germany

Meike Kasten

Affiliations Institute of Neurogenetics, University of Lübeck, Lübeck, Germany, Department of Psychiatry and Psychotherapy, University of Lübeck, Lübeck, Germany

Zbigniew K. Wszolek

Affiliation Department of Neurology, Mayo Clinic Jacksonville, Jacksonville, Florida, United States of America

Competing Interests

PR, AS, EN, EJS, MBer, MBar, and MCB declare that no competing interests exist. RR received received honoraria for lectures or educational activities not funded by industry; she serves on the medical advisory board of the Association for Frontotemporal Degeneration, on the board of directors of the International Society for Frontotemporal Dementia and holds a patent on methods to screen for the hexanucleotide repeat expansion in the C9ORF72 gene. ZKW serves as Co-Editor-in-Chief of Parkinsonism and Related Disorders, Associate Editor of the European Journal of Neurology, and on the editorial boards of Neurologia i Neurochirurgia Polska, Advances in Rehabilitation, the Medical Journal of the Rzeszow University, and Clinical and Experimental Medical Letters; holds and has contractual rights for receipt of future royalty payments from patents re: A novel polynucleotide involved in heritable Parkinson's disease; receives royalties from publishing Parkinsonism and Related Disorders (Elsevier, 2013, 2014) and the European Journal of Neurology (Wiley-Blackwell, 2012, 2013). BAC is editor of the Transactions of the Nebraska Academy of Sciences. ES receives a scholarship from the Polish Ministry of Science and Higher Education. JS is a member of the editorial board of Parkinsonism & Related Disorders and Associate Editor of the Polish Journal of Neurology and Neurosurgery. KM was funded by the MJ Fox Foundation for Parkinson’s Disease Research. KH received a congress travel grant ($1000) from the Movement Disorders Society to attend the 19th International Congress of Parkinson`s Disease and Movement Disorders. CK serves as medical adviser to Centogene, received honoraria for speaking at the Annual Meeting of the American Academy of Neurology, at Biogen Idec., and is the recipient of a Career development award from the Hermann and Lilly Schilling Foundation. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Author Contributions

Conceptualization: ZKW KM JS MK CK BAC. Data curation: AS KH MK ZKW BAC. Formal analysis: BAC KM. Funding acquisition: ZKW JS MK RR. Investigation: PR AS EN EJS M. Berdynski M. Barcikowska MCB RR KH MK ZKW. Methodology: ZKW JS MK. Project administration: ZKW JS MK. Resources: PR EN EJS M. Berdynski M. Barcikowska RR JS MK CK ZKW. Supervision: ZKW JS MK. Visualization: BAC. Writing – original draft: KM BAC. Writing – review & editing: KM BAC PR EJS JS CK MK ZKW.