Our study does not support the previously reported marginal association between AD and the ∼500 kb duplication on chromosome 15q13.3 affecting the CHRNA7 locus in a genome-wide scan of a North American dataset (Heinzen et al. 2010), which is 9.5 Mb away from the duplication on 15q11.2 discussed above. This evidence concerns the gene CHRNA7 and Alzheimer disease.