<h4>Objectives</h4>We investigated tau and neurodegeneration patterns and clinical phenotypes in carriers of a specific pathogenic variant in the PSEN1 gene and 1 nonaffected relative.<h4>Methods</h4>We included 3 symptomatic carriers of the c.436 A>C, p.Met146Leu, NM_000021.4, rs63750306 variant in the PSEN1 gene, pathogenic for autosomal dominant Alzheimer disease (AD), 1 asymptomatic carrier of the same variant, and 1 noncarrier, all belonging to the same "N" family. This evidence concerns the gene PSEN1 and Alzheimer disease.