Chromosome 9 ALS and FTD locus is probably derived from a single founder.

"Disclosure statement The authors disclose no conflicts. Appropriate Ethical Committee approvals were in place for this work."

"This work was supported in part by the Intramural Research Programs of the NIH, the National Institute on Aging (Z01-AG000949-02), and the National Institute on Neurological Disorders and Stroke. Extramural NIH grants R01AG031278, R01AG038791 supported some family assessments: NIH/NIA grant R01 AG26251 (RR) funded some analytical work. The research leading to these results has received funding from the European Community's Health Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 259867. The authors thank the Motor Neurone Disease Association of Great Britain for several grants relating to this work (RWO, AAC, PJS, HM), the ALS Association, The Angel Fund, the ALS Therapy Alliance, and the Wellcome Trust (PJS) for support.This work was also funded by the Reta Lila Weston Foundation, and by an MRC returning scientist (JH) and fellowship (SPB) award, by Microsoft Research Foundation, the ALS Association, Helsinki University Central Hospital, and the Finnish Academy. This work was also funded by Ministero della Salute, Progetti Finalizzati 2007, Fondazione Vialli e Mauro for ALS, and Federazione Italiana Giuoco Calcio. The authors also thank the Hersenstichting Nederland (www.hersenstichting.nl) for supporting this work. The authors thank the NIHR specialist Biomedical Research Centre for Mental Health at the South London and Maudsley NHS Foundation Trust (SLaM) and the Institute of Psychiatry, King's College London as well as the NIHR-funded UCL/UCLH Comprehensive Biomedical Research Centre."