The latest large-scale genetic study of Alzheimer’s disease has pinpointed 127 gene locations associated with the condition, with 48 of these being newly identified. This research also highlights specific genes that may serve as promising drug targets and identifies cell types at a higher genetic risk for developing Alzheimer’s.

“This is an intriguing phase for Alzheimer’s genetics,” says Rudolph Tanzi from Massachusetts General Hospital, pointing to the first evidence of Alzheimer’s-related genes, published in app1987.

Alzheimer’s disease accounts for the majority of cases of dementia and has a significant hereditary component; research suggests that genetics may contribute approximately 60 to 80 percent of an individual’s risk. Key genes implicated in this condition include Apoe. Individuals who inherit one copy of the APOE4 variant face a two to three times greater risk of developing the disease. Additionally, parental genetic factors may elevate risk by up to 12 times.

However, health and lifestyle choices are also crucial, and even those with genetic predispositions may not necessarily develop Alzheimer’s. “Some individuals can carry these high-risk variants yet remain unaffected,” remarks Daniel Posthuma from Vrije Universiteit Amsterdam.

To further investigate genetic influences, Posthuma’s team analyzed genomic data from around 110,000 diagnosed individuals alongside 74,000 individuals with at least one parent affected by Alzheimer’s but who had not yet shown symptoms. This data was compared to approximately 2.6 million people without Alzheimer’s disease, revealing significant gene activity linked to the disease.

This analysis uncovered 127 genes associated with Alzheimer’s, 48 of which had not been previously linked to the disease.

These newly discovered genes offer insights into the underlying mechanisms of Alzheimer’s, a condition marked by abnormal protein accumulations, such as amyloid beta and tau, in the brain. Immune cells, including a specific type known as microglia, initially migrate to these problem areas to help clear protein excess but contribute to inflammation as the disease progresses.

Posthuma’s research suggests that mutations linked to Alzheimer’s increase the expression of microglial genes while reducing neuronal gene expression, aligning with earlier findings related to neuroinflammation and cell degradation. A significant study discusses the deterioration of neurological function in Alzheimer’s.

“While the first four genes linked to Alzheimer’s suggested amyloid-beta deposition, the majority of these newly identified genes emphasize the role of immunity and neuroinflammation,” Tanzi adds.

The research team flagged three specific types of neurons exhibiting diminished gene expression in Alzheimer’s patients. “These neurons are among the first to degenerate in Alzheimer’s-affected brains,” Posthuma explains, cautioning that the exact relationship between neuronal loss and disease remains to be clarified.

Furthermore, Posthuma and her colleagues have highlighted five potential drug targets from the newly identified genes. Notably, three of these are involved in immune responses.

“There is a need to reconsider our approach, focusing more on targeting the immune system rather than solely developing anti-amyloid drugs, where most funding has been concentrated,” states Shea Andrews from the University of California, San Francisco.

The other two genes of interest include UBE2V1 and SPATA2, which appear to be linked to various neurodegenerative diseases.

Andrews asserts that an effective treatment strategy for Alzheimer’s will necessitate a multifaceted approach—combining drugs targeting amyloid, tau, and the immune system along with healthy lifestyle practices to mitigate cognitive decline.

“This study underscores that Alzheimer’s risk factors are multifaceted, indicating that no single biological pathway or cell type is solely responsible,” claims Rebecca Sims from Cardiff University, UK. “It also suggests the need for more advanced models, such as co-culture systems [growing various cell types together in the lab] and organoids to examine cellular interactions in disease.”

Though approximately 90 percent of participants in this research were of European descent, Sims noted that this study represents progress toward achieving a more diverse ancestry representation through its multi-ethnic design.

Currently, genetic assessments have limited predictive power concerning Alzheimer’s risk. However, studies like this one could enhance their relevance. Improved testing might pinpoint individuals at slightly elevated risk, prompting regular monitoring or encouraging lifestyle modifications to offset potential risks. “I’m cautious to draw definitive conclusions, as increased risk isn’t yet conclusive,” she adds.