High plasma lipoprotein phospholipase A2 activity (Lp-PLA2) is reported to be a risk factor for dementia. A loss of function polymorphism in the Lp-PLA2 gene - PLA2G7 V279F - is found almost exclusively in Asians. In 1,952 subjects with late-onset AD and 2,079 non-demented controls recruited from Japan, the PLA2G7 null allele was not associated with risk or age at onset of AD: logistic regression OR 0.98 (95% CI 0.86-1.12, p=0.81) per additional null allele, adjusted for age/age at onset, gender, and APOE ε4. Genetic deficiency of Lp-PLA2 activity is not associated with a reduced risk of AD in the Japanese population.