A C6orf10 / LOC101929163 locus is associated with age of onset in C9orf72 carriers

Altres ajuts: This work was in part supported by the Canadian Consortium on Neurodegeneration in Aging (E.R., M.Z.), the ALS Canada-Brain Canada Hudson Grant (J.R., E.R., L.Z.), James Hunter ALS Initiative and the Temerty Family Foundation (L.Z., J.R.), Alzheimer's Society grant #284 (R.F.), Argentine National Research Council (CONICET) (EIS), ALS Canada Clinical Research Fellowship (R.S.), National Institutes of Health (NIH) R35 NS097261, P50 AG016574, P01 NS084974 (RR), P50 AG016574 (N.R.G., D.W.D., J.E.P., B.F.B., R.C.P.), NIH P01 NS084974 (D.W.D.), NIH P01 AG019724 (B.L.M., W.W.S.), JPND PreFrontALS (733051042), JPND RiMOD (733051024), Memorabel-FTD (733050103) (J.C.v-S), the Flemish Government initiated Impulse Program on Networks for Dementia Research (VIND), the Methusalem Excellence Program, the Research Foundation Flanders (FWO) and the University of Antwerp Research Fund (C.V.B., J.v-d-Z.), NIH P01-AG-017586 (V.V.D.), "Investissements d'avenir" ANR-10-IAIHU-06, Assistance Publique-Hôpitaux de Paris (Clinical Research and Development Department), Programme Hospitalier de Recherche Clinique, FTLD-exome RCAOM-12123, the ANR-PRTS PREV-DEMALS project (I.L.B.), an MRC Clinician Scientist Fellowship (MR/M008525/1), the NIHR Rare Disease Translational Research Collaboration (BRC149/NS/MH), the MRC UK GENFI grant (MR/M023664/1) (J.D.R.), Swedish Research Council (Dnr 521-2010-3134, 529-2014-7504, 2015-02926), Alzheimer foundation Sweden, Brain Foundation Sweden, Swedish FTD Initiative, Swedish Brain Power, Karolinska Institutet doctoral funding, Gamla tjänarinnor, Stohnes foundation, Dementia foundation Sweden and the Stockholm County Council (ALF project) (CG), Ricerca Corrente, Italian Ministry of Health (G.R., G.B., L.B.), a National Health & Medical Research Council of Australia (NHMRC) Boosting Dementia Research Leadership Fellowship (1138223) (C.D.S.), NHMRC Senior Principal Research Fellowship (1079679) (G.M.H.), NHMRC Senior Research Fellowship (1103258) (O.P.), Fondazione CRF Grant 2015.0722, Fondo di Ateneo ex 60% anno 2017 (B.N.), Italian Ministry of health, grant RF08900000 (E.S.), Ministero dell'Istruzione, dell'Università e della Ricerca - MIUR project "Dipartimenti di Eccellenza 2018 - 2022" to Dept. of Neuroscience "Rita Levi Montalcini", University of Torino (I.R., E.R.), Acción Estratégica en Salud, integrated in the Spanish National R + D + I Plan and financed by ISCIII (Instituto de Salud Carlos III)-Subdirección General de Evaluación and the Fondo Europeo de Desarrollo Regional (FEDER- "Una manera de Hacer Europa"), Innovative Medicines Initiative 2 Joint Undertaking which receives support from the European Union's Horizon 2020 research and innovation programme (ADAPTED Grant) (A.R.). Replication data for C9orf72 carriers and for C9orf72 negative FTD/FTD-ALS patients have been obtained from the International FTD-Genomics Consortium (https://ifgcsite.wordpress.com/) dataset, funding sources of which are listed in the Supplementary materal).Discovery of disease age-of-onset modifiers is important for clinical trials and drug design. Zhang et al. perform a genome-wide analysis of epigenetic functional polymorphisms and identify an association between the C6orf10/LOC101929163 locus and age of FTD/ALS onset. The risk allele may be associated with a pro-inflammatory state in the brain. The GC-repeat expansion in C9orf72 is the most common known cause of amyotrophic lateral sclerosis and frontotemporal dementia. The high phenotypic heterogeneity of C9orf72 patients includes a wide range in age of onset, modifiers of which are largely unknown. Age of onset could be influenced by environmental and genetic factors both of which may trigger DNA methylation changes at CpG sites. We tested the hypothesis that age of onset in C9orf72 patients is associated with some common single nucleotide polymorphisms causing a gain or loss of CpG sites and thus resulting in DNA methylation alterations. Combined analyses of epigenetic and genetic data have the advantage of detecting functional variants with reduced likelihood of false negative results due to excessive correction for multiple testing in genome-wide association studies. First, we estimated the association between age of onset in C9orf72 patients (n = 46) and the DNA methylation levels at all 7603 CpG sites available on the 450 k BeadChip that are mapped to common single nucleotide polymorphisms. This was followed by a genetic association study of the discovery (n = 144) and replication (n = 187) C9orf72 cohorts. We found that age of onset was reproducibly associated with polymorphisms within a 124.7 kb linkage disequilibrium block tagged by top-significant variation, rs9357140, and containing two overlapping genes (LOC101929163 and C6orf10). A meta-analysis of all 331 C9orf72 carriers revealed that every A-allele of rs9357140 reduced hazard by 30% (P = 0.0002); and the median age of onset in AA-carriers was 6 years later than GG-carriers. In addition, we investigated a cohort of C9orf72 negative patients (n = 2634) affected by frontotemporal dementia and/or amyotrophic lateral sclerosis; and also found that the AA-genotype of rs9357140 was associated with a later age of onset (adjusted P = 0.007 for recessive model). Phenotype analyses detected significant association only in the largest subgroup of patients with frontotemporal dementia (n = 2142, adjusted P = 0.01 for recessive model). Gene expression studies of frontal cortex tissues from 25 autopsy cases affected by amyotrophic lateral sclerosis revealed that the G-allele of rs9357140 is associated with increased brain expression of LOC101929163 (a non-coding RNA) and HLA-DRB1 (involved in initiating immune responses), while the A-allele is associated with their reduced expression. Our findings suggest that carriers of the rs9357140 GG-genotype (linked to an earlier age of onset) might be more prone to be in a pro-inflammatory state (e.g. by microglia) than AA-carriers. Further, investigating the functional links within the C6orf10 / LOC101929163 / HLA-DRB1 pathway will be critical to better define age-dependent pathogenesis of frontotemporal dementia and amyotrophic lateral sclerosis