In this study, haplotypic variants within this gene cluster were associated with AD at TTC12 (markers rs1893699–rs723077) in both the case–control and family-based samples, as well as variants around exon 12 of NCAM1 and exons 2 and 5 of ANKK1 only in the case–control sample. This evidence concerns the gene NCAM1 and Alzheimer disease.