Accepted for Publication: November 27, 2013.
Published Online: January 20, 2014. doi:10.1001/jamaneurol.2013.6002.
Study concept and design: All authors.
Acquisition of data: Burrell, Hodges.
Analysis and interpretation of data: Devenney, Hornberger, Irish, Mioshi.
Drafting of the manuscript: Devenney, Irish, Tan, Kiernan, Hodges.
Critical revision of the manuscript for important intellectual content: All authors.
Statistical analysis: Devenney.
Study supervision: Kiernan, Hodges.
Conflict of Interest Disclosures: Dr Hodges receives publishing royalties for Cognitive Assessment for Clinicians (Oxford University Press, 2007) and Frontotemporal Dementia Syndromes (Cambridge University Press, 2007). No other disclosures were reported.
Funding/Support: Dr Devenney was supported by a grant from the Motor Neurone Disease Association. Drs Devenney, Tan, Kiernan, and Hodges were supported by grant 1037746 from the National Health and Medical Research Council of Australia. Dr Hornberger was supported by Research Fellowship DP110104202 from the Australian Research Council. Dr Irish was supported by Discovery Early Career Research Award DE130100463 from the Australian Research Council. Dr Mioshi was supported by Early Career Fellowship 1016399 from the National Health and Medical Research Council of Australia. Drs Mioshi, Burrell, and Tan were supported by the Motor Neurone Disease Research Institute of Australia. Dr Tan was supported by the Mick Rodger Benalla MND Research Grant.
Role of the Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.
Additional Contributions: John Kwok, PhD, and Carol Dobson Stone, Neuroscience Research Australia and School of Medical Sciences, University of New South Wales, Sydney, Australia, carried out the genetic analysis on blood samples from participants in this study. They did not receive compensation for their contributions.