Biospecimen Core

BIOSPECIMEN CORE: ABSTRACT American Indians and Alaskan Natives (AI/ANs) and Native Hawaiians and Pacific Islanders (NHPIs) are subject to disparities in many health conditions, including Alzheimer?s disease and related dementias (ADRD).

Yet these populations remain understudied, so that we lack the biospecimens and other data needed to identify their biological and genetic risk factors for ADRD.

The magnitude of the problem can be illustrated by the database of the National Alzheimer?s Coordinating Center, which has collected APOE genotypes from only 135 AI/ANs and 17 NHPIs over the past 30-years.

The paucity of biomarker data is especially concerning because extant literature suggests that the APOE ?4 allele is not associated with dementia among AIs or the Chamorro people of Guam, in sharp contrast with findings on non-Indigenous US populations. Such population- specific differences highlight the need for robust biospecimen collection among AI/ANs and NHPIs.

Unfortunately, few genetic studies have been conducted in their communities, as biospecimen collection is often viewed negatively by AI/ANs, NHPIs, and other Indigenous populations.

Yet, we have shown that AI/ANs are more willing to engage in genetic research if community stakeholders help design projects, collect data, and interpret results. Similar findings on biobanking have been reported for NHPIs. The Biospecimen Core will be co-led by Dr.

John Kauwe, a Native Hawaiian who is internationally known for his work on the genetics of ADRD and other diseases; and Dr. Perry Ridge, an expert in bioinformatics and genomic sequencing of ADRD biomarkers, both from Brigham Young University.

This Core will have access to biospecimens donated by AI/ANs and NHPIs through several sources, including NEAR Research Projects 2 and 3 and Brain Train workshops conducted by our 8 Satellite Centers in areas of the US where 90% of AI/ANs and NHPIs reside.

The Specific Aims of the Biospecimen Core are to: 1) Isolate and store DNA from biospecimens collected from participants in Research Projects, Satellite Center activities, and other sources.

We expect to assemble ~2,700 saliva samples linked to self-reported and objective data from AI/ANs and NHPIs and ~390 blood samples for future biomarker studies; 2) Collect and validate genotypes for each saliva sample initially using the Illumina Omni2.5 array.

These data will be used to evaluate genes and variants that confer ADRD risk, such as APOE; 3) Provide annotated genotype data for key disease markers and polygenic risk scores for ADRD; and 4) Serve as a resource for processing, storing, and cataloging biospecimens obtained by ongoing and future studies with other AI/AN and NHPI cohorts.

Biospecimens and datasets will be available through existing and new partnerships that will elucidate the genetic risk in these groups. The National Institute on Aging is committed to ensuring adequate representation of minorities in ADRD research. Our efforts will result in a large repository of hitherto unavailable biospecimens collected from AI/ANs and NHPIs.

Building this repository is vital to fulfilling the Institute?s commitment and characterizing unique ADRD genetic risk and protective profiles in these populations.