2022 Alzheimer's Association Research Grant to Promote Diversity (AARG-D)
Novel Alzheimer’s disease transethnic polygenic risk scores in Latinos
Can a novel genetic tool detect Alzheimer’s in Hispanic/Latino individuals of different ethnic backgrounds?
Iris Broce-Diaz, Ph.D.
University of California, San Diego - Health Sciences
San Diego , CA - United States
Background
According to the 2022 Alzheimer’s Association Facts and Figures Report, studies indicate that older Hispanic/Latino American adults are about one and one-half times as likely to have Alzheimer’s or other dementias as older White Americans. Facts and Figures also notes that the larger Hispanic American community is a very diverse group of individuals with different cultural histories and health profile.s Further, there is evidence that Alzheimer’s prevalence may differ from one Hispanic ethnic group to another (for example, Mexican Americans compared with Caribbean Americans).
These disparities indicate the need to accurately diagnose dementia in Hispanic Americans, a goal that has been hampered by problems with currently-available diagnostic tools. Such tools include positron emission tomography (PET) brain scans, which detect levels of dementia-related proteins (tau and beta-amyloid) in the brain. PET scans are not only expensive to administer, but they have been developed largely for people of White European ancestry. Research indicates that they do not detect Alzheimer’s as accurately in Hispanic/Latino individuals. New diagnostic tools need to be more cost-effective and better tailored for the different ethnic groups within the Hispanic/Latino population. One potential method may involve identifying specific genes linked to dementia risk in these groups.
Research Plan
Dr. Iris Broce-Diaz and colleagues will devise a tool for diagnosing Alzheimer’s in multiple Hispanic/Latino communities. This tool will be developed with data from several large-scale genome-wide association studies (or GWAS). GWAS use datasets from large groups of individuals to identify genetic factors associated with an increased or decreased risk of developing Alzheimer’s. Specifically, the researchers will use a newly-developed statistical method to analyze GWAS data from three different studies – of Finnish, European and Black American individuals – and identify a pattern of genes linked to Alzheimer’s risk in multiple ethnic backgrounds. They will then test how well this “transethnic polygenic risk score” can detect Alzheimer’s and mild cognitive impairment (or MCI, a condition of subtle memory loss that may precede Alzheimer’s) in a large, diverse group of older Hispanic/Latino individuals. The researchers will also assess whether the tool is more effective than standard PET-based methods of dementia diagnosis.
Impact
Results from this study will shed new light on how genetic-based risk factors for Alzheimer’s differ among multiple Hispanic/Latino communities. They could also lead to a novel method of detecting early-stage Alzheimer’s in these communities.