About the Authors

Lydia Coulter Kwee

Affiliations Epidemiology Research and Information Center, Durham Veterans Affairs Medical Center, Durham, North Carolina, United States of America, Center for Human Genetics, Duke University Medical Center, Durham, North Carolina, United States of America, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America

Yutao Liu

Affiliations Epidemiology Research and Information Center, Durham Veterans Affairs Medical Center, Durham, North Carolina, United States of America, Center for Human Genetics, Duke University Medical Center, Durham, North Carolina, United States of America, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America

Carol Haynes

Affiliations Center for Human Genetics, Duke University Medical Center, Durham, North Carolina, United States of America, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America

Jason R. Gibson

Affiliations Epidemiology Research and Information Center, Durham Veterans Affairs Medical Center, Durham, North Carolina, United States of America, Center for Human Genetics, Duke University Medical Center, Durham, North Carolina, United States of America, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America

Annjanette Stone

Affiliation Pathology and Laboratory Medicine Service and Research Service, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, United States of America

Steven A. Schichman

Affiliations Pathology and Laboratory Medicine Service and Research Service, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, United States of America, Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America

Freya Kamel

Affiliation Epidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, United States of America

Lorene M. Nelson

Affiliation Division of Epidemiology, Department of Health Research and Policy, Stanford University School of Medicine, Stanford, California, United States of America

Barbara Topol

Affiliation Division of Epidemiology, Department of Health Research and Policy, Stanford University School of Medicine, Stanford, California, United States of America

Stephen K. Van Den Eeden

Affiliation Division of Research, Kaiser Permanente Northern California, Oakland, California, United States of America

Caroline M. Tanner

Affiliation The Parkinson's Institute, Sunnyvale, California, United States of America

Merit E. Cudkowicz

Affiliation Massachusetts General Hospital, Neurology Clinical Trial Unit, Harvard Medical School, Boston, Massachusetts

Daniela L. Grasso

Affiliation Massachusetts General Hospital, Neurology Clinical Trial Unit, Harvard Medical School, Boston, Massachusetts

Robert Lawson

Affiliation Massachusetts General Hospital, Neurology Clinical Trial Unit, Harvard Medical School, Boston, Massachusetts

Sumitra Muralidhar

Affiliation Office of Research and Development, Department of Veterans Affairs, Washington, District of Columbia, United States of America

Eugene Z. Oddone

Affiliations Epidemiology Research and Information Center, Durham Veterans Affairs Medical Center, Durham, North Carolina, United States of America, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America

Silke Schmidt

Contributed equally to this work with: Silke Schmidt, Michael A. Hauser

Affiliations Epidemiology Research and Information Center, Durham Veterans Affairs Medical Center, Durham, North Carolina, United States of America, Center for Human Genetics, Duke University Medical Center, Durham, North Carolina, United States of America, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America

Michael A. Hauser

Contributed equally to this work with: Silke Schmidt, Michael A. Hauser

mike.hauser@duke.edu

Affiliations Epidemiology Research and Information Center, Durham Veterans Affairs Medical Center, Durham, North Carolina, United States of America, Center for Human Genetics, Duke University Medical Center, Durham, North Carolina, United States of America, Department of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America

Competing Interests

SM set program policies as part of the Veterans Affairs Office of Research and Development's management team. SAS owns stock in Affymetrix, Inc. CMT serves as a consultant for IMPAX Pharmaceuticals, Adamas Pharmaceuticals, Allergan Pharmaceuticals, and Genentech and receives research support from National Institute of Neurological Disorders and Stroke, Agency for Healthcare Research and Quality, United States Department of Defense, Michael J. Fox Foundation, Parkinson Disease Foundation, Parkinson Unity Walk, James & Sharron Clark. None of these consulting or funding relationships are related to ALS research. This does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials. All other authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: SS MAH SM EZO. Performed the experiments: JRG AS. Analyzed the data: LCK CH SS. Contributed reagents/materials/analysis tools: FK LMN BT SKV CMT MEC DLG RL. Wrote the paper: LCK YL SS MAH. Oversaw experiment: YL SAS MAH. Obtained funding: EZO SS.