However, in Alzheimer's disease patients, the propagation sequence of tau protein differs from the one observed in cognitively unimpaired older adults and seems to follow a consistent, stereotypical and reproducible pattern: In cross-sectional autopsy studies, pathological tau first appeared in the transenthorinal cortex before spreading into neighboring regions in the limbic and temporal cortex. This evidence concerns the gene MAPT and early-onset autosomal dominant Alzheimer disease.