APOE ε4 Allele Frequency Among Cognitively Healthy Members of an Ojibwe Tribal Nation.

Objectives: APOE ε4 frequency varies by geography and ancestry. We provide data regarding the frequency of this allele in the Ojibwe people, the fifth largest Indigenous people in the United States. Methods: Population study including 33 cognitively normal older individuals of an Ojibwe Tribal Nation (total population: 984; all with ≥25% Ojibwe ancestry). Results: APOE ε4 allele frequency was 19.7%, which is comparable with other cognitively normal American Indian, Alaskan Native, and non-Hispanic White populations of the United States and Europe, with the exception of a lower frequency among Choctaw Nation of Oklahoma participants with >50% American Indian ancestry. Discussion: While some global populations have very low APOE ε4 prevalence, this allele appears common among American Indian Tribal Nations included thus far in the United States. Because APOE ε4 is a cornerstone for novel diagnostics and therapeutics for Alzheimer disease (AD), future study is warranted to understand ancestry-dependent effects of APOE ε4 on AD risk and biology.