Alzheimer’s disease (AD) is an increasingly prevalent neurologic disorder characterized by progressive impairment in cognition, behavior, functioning, and global presentation. Evidence suggests that these impairments are associated with changes in the limbic system's electrophysiology and neuropathology. Changes have been specifically associated with serotonin, a neurotransmitter in the limbic system. Minimal information is known about the contribution of serotonin gene variants to the development and progression of AD’s phenotype.
The purpose of this pilot study is to describe the relationship between serotonin transporter and receptor gene variants and clinical phenotype in persons with advanced AD.
A longitudinal, descriptive study design was used. Thirty-seven subjects diagnosed with probable AD were recruited from five long-term care facilities. Whole blood or cheek cells were collected for DNA extraction and genotyping. Measures of behavioral features (Cohen-Mansfield Agitation Inventory, Neuropsychiatric Inventory), cognitive status (Global Deterioration Scale, Severe Impairment Battery), and functional skills (Functional Abilities Checklist) were collected at four-month intervals over one year.
Subjects had a baseline mean age of 85.5 years (onset mean age of 77.1 years) and moderate to severe impairment in cognition, behavior, and functioning. Subjects were genotyped for the variants in the serotonin transporter and receptor. Statistical analyses are underway to characterize the clinical phenotype across multiple time points. Survival analysis will be used to compare genotype groups according to age at onset. Repeated measures MANCOVA will be used to compute the relationship between genotypes and clinical phenotype over time.
Results from this pilot study will contribute to the development of a larger study examining the relationship between genetic variants, electrophysiological changes, and clinical phenotype of persons with AD. More importantly, these results can contribute to nurses' incorporation of genetic information into the care of persons with AD through evidence-based practice for positive outcomes and improved health care.
Session #1219 - Poster Session I
The 29th Annual MNRS Research Conference (April 1-4, 2005)