The frequency of the MAPT H1H1 genotype is increased in limbic-predominant AD compared with typical and hippocampal-sparing AD.9,10 However, a study reported that typical AD had the highest frequency of MAPT H1H1 carriers, followed by limbic-predominant and hippocampal-sparing AD.22 These findings suggest that the MAPT H1H1 genotype may play a role in the medial temporal lobe predilection for NFT. This evidence concerns the gene MAPT and Alzheimer disease.