Mol Psychiatry. 2015 Aug 25. doi: 10.1038/mp.2015.121. [Epub ahead of print]

Nicolas G, Charbonnier C, Wallon D, Quenez O, Bellenguez C, Grenier-Boley B, Rousseau S, Richard AC, Rovelet-Lecrux A, Le Guennec K, Bacq D, Garnier JG, Olaso R, Boland A, Meyer V, Deleuze JF, Amouyel P, Munter HM, Bourque G, Lathrop M, Frebourg T, Redon R, Letenneur L, Dartigues JF, Génin E, Lambert JC, Hannequin D, Campion D; CNR-MAJ collaborators.

The SORL1 protein plays a protective role against the secretion of the amyloid peptide, a key event in the pathogeny of Alzheimer's disease. We assessed the impact of SORL1 rare variants in early-onset Alzheimer's disease (EOAD) in a case-control setting. We conducted a whole exome analysis among 484 French EOAD patients and 498 ethnically matched controls. After collapsing rare variants (minor allele frequency 1%), we detected an enrichment of disruptive and predicted damaging missense SORL1 variants in cases (odds radio (OR)=5.03, 95% confidence interval (CI)=(2.02-14.99), P=7.49.10-5). This enrichment was even stronger when restricting the analysis to the 205 cases with a positive family history (OR=8.86, 95% CI=(3.35-27.31), P=3.82.10-7). We conclude that predicted damaging rare SORL1 variants are a strong risk factor for EOAD and that the association signal is mainly driven by cases with positive family history.