Adjusting for age, sex and brain pathology, we found that the level of the 1N/4R MAPT isoform was inversely associated with global parkinsonism (β = -0.0173; p = 0.008, adjusted for age, sex, study and pathology), bradykinesia (β = -0.0281; p = 0.008, adjusted for age, sex, study and pathology) and gait impairment (β = -0.019; p = 0.039) at the last visit prior to death. This evidence concerns the gene MAPT and Parkinson disease.