Background Alzheimer disease (AD) is a prevalent late-onset disorder, characterized by dementia. Genetic variants may contribute to AD susceptibility and variability in disease progression. The Saitohin (STH) gene (17q21.1) is a candidate gene for AD, based upon evidence that a STH polymorphism is overrepresented in persons with late onset AD. Common allelic variants in the Apolipoprotein E gene (19q13.2) are also known to influence risk for developing AD. Little is known about the contribution of these genes, either individually or collectively, to phenotypic variability in persons with AD.
Purpose The purpose of this pilot study is to explore the relationship between the STH and APOE genes and variability in cognition, function, and behavior over time in persons with AD.
Methodology A longitudinal correlational study design was used. Seventy-two subjects with a diagnosis of probable AD were recruited from long-term care and home settings. Subjects exhibited a mean age at onset of 72.9 years (S.D.=9.74); 96% were Caucasian. All subjects were genotyped for the STH(Q7R) polymorphism and the three APOE allelic variants, using DNA extracted from blood or buccal samples. Subjects also were genotyped for five population-specific markers (LPL, APO4, Sb19.3, AT3 I/D and MID 152) to further explore ethnic admixture. Multiple measures of cognition, function, and behavior were collected at four month intervals over a twelve month period.
Results Statistical analyses are underway to describe the phenotypic characteristics of the sample across timepoints. Survival analysis will be used to compare genotype groups according to age at onset. Repeated measures MANCOVA will be used to test the relationship between genotypes and profiles of cognition, function, and behavior over time. Genotype-phenotype correlational research in persons with AD is critical to understanding the biologic basis of this complex disease.
Session #1222 - Undergraduate Submissions
The 29th Annual MNRS Research Conference (April 1-4, 2005)