Researchers Identify 42 New Genes for Alzheimer's Disease

A major international study recently identified 75 genes associated with an increased risk of developing Alzheimer's disease, including 42 new genes not previously discovered. 

The study involving UK Dementia Research Institute researchers enrolled over 100,000 individuals with Alzheimer's disease and over 600,000 healthy individuals across the UK, US, Australia, and Europe. Researchers studied the differences in their genetic makeup. 

Notably, 60–80% of disease risk is based on genetics. Therefore, researchers must continue to uncover the biological causes and develop treatments for the millions of people affected globally.  

The previously unknown genes point to additional pathways for disease progression aside from the well-known APOE e4 gene or the development of amyloid-beta and tau. These two hallmark proteins build up in the brain as Alzheimer's disease progresses.  

Overall, the findings show for the first time that a specific biological signaling pathway involving TNF-alpha, a protein with a vital role in inflammation and the immune system, is implicated in Alzheimer's disease and could damage the brain cells.  

Additionally, researchers noted evidence that the dysfunction of microglia, which regulate brain development and maintenance of the neuronal network, contributes to disease pathology.  

On the basis of these findings, researchers devised a genetic risk score to determine how likely patients with cognitive impairment will develop Alzheimer's disease within three years of first showing symptoms.  

"This is a landmark study in the field of Alzheimer's research and is the culmination of 30 years' work," Julie Williams, study co-author, center director at the UK Dementia Research Institute at Cardiff University, said in the study.   

"The results support our growing knowledge that Alzheimer's disease is an extremely complex condition, with multiple triggers, biological pathways, and cell types involved in its development. We are unmasking more of these causes year on year, and this also provides greater opportunities from which to develop therapeutics," Williams continued.  

The next step toward finding treatments for Alzheimer's disease is for researchers to focus on the specific risk genes identified in this study and closely examine their role in the dysfunction and death of brain cells. 

Additionally, it is crucial to broaden studies to look at other demographics in the future.