ICYMI: How Do Ancestry and Environment Influence Brain Illness Risk Among Black Americans?

Mattlyn Young, the first student from Morgan State University to conduct research at the Lieber Institute for Brain Development as part of the African Ancestry Neuroscience Research Initiative, pictured working in a lab. Photo taken November 2021.

Tyler Lee. Image courtesy of the Lieber Institute for Brain Development

Your genes are just one of several factors affecting your overall health. Genetic ancestry can be an important indicator of how likely someone is to develop a particular disease. In a paper published May 20 in Nature Neuroscience, researchers from the African Ancestry Neuroscience Research Initiative (AANRI) examined the role genetic ancestry plays in risk for brain illness. While risk for some conditions is associated with genetic influences, others are affected by environmental factors.

AANRI is a collaboration between Baltimore-based institutions — Morgan State University, a historically Black university, and the Lieber Institute for Brain Development (LIBD) located at Johns Hopkins University — and leaders within the local Black community. The initiative’s goal is to advance racial equity and fill widespread information gaps within the neuroscience field.

In their premier paper published in May, the team examined how the information coded in genes is “expressed” to create proteins or certain RNA molecules, which in turn determine how our cells function. They analyzed tissue samples derived from neurotypical Black Americans whose families donated their brains after their deaths. They found African ancestry-associated gene expression differences contributed to a higher prevalence of neurological disorders, including Alzheimer’s, and immune-related traits like rheumatoid arthritis, but not psychiatric conditions like schizophrenia or behavioral traits like neuroticism when assessed alongside differences related to European genetic ancestry. This is important because Black Americans face a higher risk of brain illnesses like Alzheimer’s and stroke compared to other demographics. Black adults are also 20% more likely to experience mental health conditions like anxiety or depression. However, for mental health and behavioral conditions, environmental influences may be driving differences in gene expression as opposed to genetic ancestry, according to AANRI.

Genetic ancestry and race aren’t synonymous. Although a person’s race can also influence their health, it's a social construct with no basis in biology. Genetic ancestry, meanwhile, can be assessed and analyzed. The study’s authors hope clinicians could one day use this information to design personalized medical interventions that meet the needs of a specific patient.

Big Picture: AANRI researchers note in their paper that people with African ancestry make up less than 5% of major brain disorder studies. In contrast, more than 80% of genomic datasets are derived from people of European descent, according to the initiative. Their new research marks a crucial step forward in the effort to understand the relationship between genetic ancestry and brain health, address longstanding racial injustice in the medical field and eventually improve health outcomes for Black people in the United States. Daniel Weinberger, the study’s senior author and CEO of LIBD, told Science that he hopes to pursue comparable research efforts to assess the brain genetics of people of Asian and Indigenous North American ancestry.

Read More: A new study of brain samples from Black people shows the influence of environment and genetics on mental disorders. Science

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About the Author

Bella Isaacs-Thomas

Bella is the Staff Writer and Editor for BrainFacts.org. She previously worked as a digital science reporter at PBS NewsHour, where she was named a fellow in the 2022-2023 class of the National Science-Health-Environment Reporting Fellowships (SHERF) and earned a 2021 D.C. Science Writers Association Newsbrief Award for writing. She graduated from the University of Michigan with a bachelor's degree in 2018.