Investigating APOE Genotypes in Individuals with a Family History of Alzheimer’s Disease with the MindCrowd Platform
Alzheimer’s disease (AD), the leading cause of dementia, is a progressive neurodegenerative disorder that first presents itself clinically as deficits in cognition. AD is currently the sixth leading cause of death in the U.S. and is projected to affect one in 25-30 Americans by 2050. While a large body of evidence points to several genetic and environmental factors influencing AD, these factors only explain a small fraction of AD cases. MindCrowd was developed as an innovative approach to study and help elucidate the unknown factors underlying AD. MindCrowd is a web-based assessment designed to recruit a very large and diverse cohort of participants from across the world. The web-based assessment consists of a simple reaction time and paired-associates learning (PAL) tasks as well as a series of demographic questions. Participants completing the assessment with a first-degree relative (e.g., sibling, mother, or father) diagnosed with AD were identified as having a family history of AD (FH). A subset of FH participants was solicited via email to self-collect dried blood spots (DBS), which were mailed back to the laboratory. DBS were processed via Polymerase Chain Reaction (PCR), Restriction Fragment Length Polymorphisms, and gel electrophoresis to determine a participant’s apolipoprotein E (APOE) genotype. APOE genotypes were associated with PAL scores to determine the effect of APOE genotype on cognition. Preliminary analyses revealed no significant effect; however, an overall trend suggested that FH carriers of the APOE E4 allele performed worse when compared to FH non-carriers in participants 18 to 65 years old. Collectively, these preliminary findings suggest that in FH individuals, APOE genotype does not alter cognition. Future studies of FH participants will evaluate a broad array of targets to help reveal unknown factors contributing to AD.