[34]. While this is aligned with our findings of association with depression and neuroticism, our strongest support for SYNJ2 was with agreeableness, where rs350292 showed association in our replication sample of more than 17 000 participants and the direction of the effect was consistent between the original and replication sample. Of note, the meta-analysis of older cohorts—but not the younger cohorts—showed a significant effect of this SNP with agreeableness. Agreeableness, particularly its straightforwardness facet, is predictive of survival in Americans older than 66 years [9]. Six other SNPs in SYNJ2 were in high linkage disequilibrium with this SNP but, like rs350292, they were all intronic SNPs, with no documented previous associations. Ours is the first association study to investigate SYNJ2 and personality traits. Synaptojanins are a family of phosphoinositide phosphatases; and like synaptojanin 1, mammalian synaptojanin 2 is involved in dynamin and clathrin-mediated synaptic vesicle recycling but, distinct from SYNJ1 it is expressed more widely (both are concentrated in nerve terminals) and is linked to membrane trafficking and signal transduction pathways [35, 36].
