Footnotes

• Contributors Study concept and design: EG-T, JVDZ, CVB. Gathering of data: EG-T, JVDZ, MR, JE-P, AG-R, EN, MJS, JP-P, RG-L, IG, MC, CVB, DB-H. Analysis and interpretation of data: EG-T, JVDZ, MR, MJS, JP-P, IG, MC, CVB. Drafting of the manuscript: EG-T. Critical revision of the manuscript for important intellectual content: JVDZ, MR, CVB, AG-R, EN, RG-L. Obtained funding: EG-T, JP-P, CVB. Administrative, technical and material support: MR, RG-L, JP-P, MJS. Study supervision: EG-T, CVB, RG-L.

• Funding Supported by grants from the Ministry of Science and Technology (SAF2010-18277), Instituto de Investigación Sanitaria Carlos III (PI14-00088 and PI14-00099), FUNDELA (Spanish Foundation to the development of ALS research), ADELA (ALS Spanish Association) and funds from FEDER (Spain). Genetic studies of TBK1 in the EU EOD Consortium were funded in part by the Belgian Science Policy Office Interuniversity Attraction Poles program, the Flemish Government initiated Flanders Impulse Program on Networks for Dementia Research (VIND), the Flemish Government initiated Methusalem Excellence Program, the Research Foundation Flanders (FWO), the University of Antwerp Research Fund (Belgium).

• Competing interests None declared.

• Ethics approval Research Ethics Committee at Fundacin Jimnez Daz (Madrid, Spain).

• Provenance and peer review Not commissioned; externally peer reviewed.