It is interesting that others have found that psychotic manifestations in an AD cohort was associated with the 5-HTTLPR L allele, but was not influenced by the APOE ε4 allele (Quaranta et al., 2009), yet our sample set did not reveal any changes in dopamine metabolism (often associated with psychosis) with the 5-HTTLPR alleles. The gene discussed is APOE; the disease is Alzheimer disease.