Genetics of neuropsychiatric symptoms in patients with Alzheimer's disease: A1-year follow-upstudy

Aim The aim of this study was to investigate the associations between candidate gene variants and domains of neuropsychiatric symptoms (NPS) and the changes in these associations over a 1-year period. Methods Seven hundred and ninety-three Taiwanese participants (47.8% female) with Alzheimer's disease (AD) were enrolled. Genes associated with a risk of developing AD were selected as candidate genes. NPS were assessed using the Neuropsychiatric Inventory Questionnaire (NPI-Q), and the NPI-Q total score and sub-scores for the Psychosis, Mood, and Frontal Syndrome domains were calculated. Results Patients with AD and theAPOE epsilon 4 allele exhibited more obvious symptoms of psychosis. Mood symptoms were associated withCD33rs3865444 andEPHA1rs11767557, and frontal symptoms were associated withSORL1rs3824968. A 1-year Time x Alleles interaction effect ofCD33rs3865444 on mood symptoms was discerned. Conclusion Risk genes of AD, which are also associated with NPS, areAPOE epsilon 4 for psychosis,CD33andEPHA1for mood symptoms, andSORL1for frontal symptoms. The association betweenCD33and mood symptoms is dynamic and could change over 1 year; however, the results should be interpreted with caution because corrections for multiple comparisons were not performed.