African Americans are more likely to carry genetic variants associated with dementia

African Americans are more likely than non-Hispanic White Americans to carry genetic variants associated with the soluble lower cerebrospinal fluid (CSF) trigger receptor expressed in myeloid cells 2 (sTREM2), an immune mediator in Alzheimer’s disease (AD). This is based on study results published in Neurology Genetics.

The study was an examination of CSF-sTREM2 levels and genetic analyzes in older adults living in shared apartments with and without cognitive impairment. The individuals included in this study had previously participated in research that focused on memory and aging. Study researchers classified the participants as African American (n = 91) or non-Hispanic white (n = 868).

Overall, the African American participants were significantly younger than those in the non-Hispanic white group (66.1 ± 8.2 versus 69.3 ± 9.2 years; P = 0.002). Additionally, African Americans were less likely to have dementia (13% versus 25%; P = 0.01) and less likely to report a family history of dementia (44% versus 56%; P = 0.03) reported fewer school years (15.2 ± 2.9 versus 15.9 ± 2.7; P = 0.02).

CSF-sTREM2 levels were significantly lower in African Americans than in participants identified as non-Hispanic whites (1336 ± 470 versus 1856 ± 624 pg / ml; P <0.0001). African Americans were also more likely to carry TREM2 coding variants associated with lower CSF-sTREM2 (15% versus 3%; P <0.0001). In addition, African Americans were significantly less likely to carry the rs1582763 minor allele near MS4A4A, which is associated with higher CSF sTREM2 (8% versus 37%; P <0.0001).

In an independent cohort of 23 African American and 917 non-Hispanic white participants, CSF-sTREM2 levels were also lower in participants who identified themselves as African American (P = 0.03). Similarly, African Americans were more likely to carry coding variants of TREM2 (22% versus 4%; P = 0.002) and less likely to carry the rs1582763 minor allele (16% versus 37%; P = 0.003). compared to non-Hispanic white participants.

A major limitation of this study was the small number of participants in the African American group compared to the non-Hispanic white group.

The study’s researchers concluded that “developing AD therapies that are less likely to be effective in AA would exacerbate the long-standing injustices of AA,” and that their “study highlighted the importance of careful Assessment of the effects of breed on AD pathophysiology highlights “.

Disclosure: Several authors of the study have stated that they are part of the pharmaceutical industry. For a full list of the authors’ information, see the original reference.


Schindler SE, Cruchaga C., Joseph A. et al. African Americans reported differences in CSF-soluble TREM2 and associated genetic variants. Published online March 4, 2021. Neurol Genet. doi: 10.1212 / NXG.0000000000000571

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