Genetic Investigation in African American Families Highlights Novel Alzheimer’s Disease Associations
An NIA-funded research revealed a particular genetic locus and rare variants in individuals of African descent that could be linked to the risk of Alzheimer’s disease. Published in the Neurobiology of Aging, these findings also unveiled a new gene that may play a role in the disease’s development. Scientists from the University of Miami, along with partner institutions, delved into genetic data from multigenerational African American families enrolled in the study. These 51 families, comprising 245 members, presented a unique profile: each had at least two relatives with an Alzheimer’s diagnosis and one elderly member without any cognitive disorders, free from common early-onset Alzheimer’s genetic mutations. Their genetic information, sourced from the Research in African American Alzheimer Disease Initiative and the Late Onset of Alzheimer’s Disease Family Based Study, was meticulously analyzed to pinpoint any genetic disparities linked to Alzheimer’s.
In nine families, a certain section on chromosome 5 emerged as a genetic zone of significance. Within this area, researchers discovered rare genetic variants with connections to Alzheimer’s. For five families, the risk seemed to hinge on a variation in the gene for inhibitory synaptic factor 2B (INSYN2B), which is believed to modulate neural activity suppression. These individual variants could potentially influence the gene’s expression regulation.
An in-depth analysis of the tissue samples revealed that the INSYN2B gene had diminished activity compared to genes responsible for regulating standard cellular functions. The researchers indicated that this low activity level in the INSYN2B gene could imply that even minor fluctuations in the overall gene activity might significantly impact the susceptibility to Alzheimer’s disease.
The study also sheds light on the possibility that genetic elements could play a role in the varying degrees of Alzheimer’s risk among African Americans, a demographic that has been historically underrepresented in genetic studies related to Alzheimer’s. The findings underline the necessity of incorporating diverse ethnic groups in genetic research to gain a comprehensive understanding of the genetic factors influencing Alzheimer’s. Continued investigation into these genetic variables could pave the way for the development of new genetic markers that aid in evaluating the risk of Alzheimer’s in individuals with African heritage.