Recent genetic studies revealed that Single Nucleotide Polymorphisms (SNPs) of the AQP4 gene were associated with altered rates of cognitive decline after AD diagnosis, with two SNPS (rs9951307 and rs3875089) associated with slower cognitive decline and two (rs3763040 and rs3763043) associated with more rapid cognitive decline after AD diagnosis. This evidence concerns the gene AQP4 and Alzheimer disease.