Genetic variation in the alpha 7 nicotinic acetylcholine receptor is associated with delusional symptoms in Alzheimer's disease.

Psychotic symptoms are common in Alzheimer's disease (AD) and have a negative impact on quality of life. It is suggested that psychotic symptoms may be attributed to genetic risk factors which are revealed during neurodegeneration. CHRNA7, the gene for the alpha 7 nicotinic acetylcholine receptor, has been associated with schizophrenia in linkage and association studies. Hence we investigated single SNPs and haplotypes in CHRNA7 in relation to AD with psychosis in a large, well-characterised and previously described cohort within the Northern Ireland population. A significant association between delusions and the T allele of rs6494223 (P = 0.014, OR = 1.63, CI = 1.22-2.17) was found. This suggests that the alpha 7 receptor may be a suitable target for the treatment of AD with psychosis.