Recently, mutations in phospholipase D3 (PLD3) were reported in late-onset Alzheimer's disease (AD). By screening the coding regions of PLD3 for variants in a European cohort of 1,089 AD cases, 182 individuals with frontotemporal lobar degeneration and 1,456 controls, we identified 32 variants with a minor allele frequency <5% and observed an excess of rare variants in individuals with late- but not early-onset AD (P=0.034, χ (2)-test; odds ratio=1.46).