A new study discovers the link between our DNA and the chance of getting Alzheimer’s disease

Alzheimer’s disease, also known as AD, is a complicated health condition that impacts millions of people across the globe. It gradually worsens a person’s thinking skills and memory, and currently, we don’t have a cure for it. While lifestyle choices like the food we eat and the exercise we do can affect the chances of getting Alzheimer’s, our genes also play a big part. In fact, scientists believe that 60 to 80 percent of our risk of getting Alzheimer’s comes from our genes.

But figuring out the exact genes and how they contribute to Alzheimer’s is no small feat. It needs big studies that look at the complete genetic information of thousands of Alzheimer’s patients and healthy people. These studies can reveal areas within our genetic information that might increase or decrease our chances of getting Alzheimer’s and provide some clues about how this happens biologically.

A significant study published in Nature Genetics has managed to do this. It’s the largest study of its kind that looks at the relationship between our genes and Alzheimer’s. Hundreds of scientists worldwide took part in this study, which combined the genetic information from 111,326 Alzheimer’s patients and 677,663 healthy individuals.

The study found 75 areas within our genes that are connected to the risk of Alzheimer’s, and 42 of these are new discoveries. Some of these areas confirm what we already knew about the role of amyloid and tau proteins in Alzheimer’s. These proteins build up unusually in the brains of Alzheimer’s patients, forming plaques and tangles that damage how brain cells work.

Interestingly, the study also discovered new information, such as the involvement of a particular pathway involving an immune protein called TNF-alpha in Alzheimer’s. This is the first time TNF-alpha, a protein known to control inflammation and immune responses, has been linked to Alzheimer’s development. These responses to harmful things in our bodies are now being seen as important factors in how Alzheimer’s develops.

The study also suggests that we could potentially develop a ‘genetic risk score’ for Alzheimer’s. This score would be based on a combination of changes in our genes that affect how likely we are to get Alzheimer’s. Such a score could help predict who is most likely to get Alzheimer’s or progress from mild cognitive impairment (a slight decline in memory and thinking skills) to full-blown Alzheimer’s. The researchers found that this genetic risk score could improve the prediction of Alzheimer’s risk by 1.6 to 1.9 times, on top of considering age and the presence of the APOE ε4 allele, which is currently the strongest known genetic risk factor for Alzheimer’s.

This study is a major win for Alzheimer’s research and gives us new insights into the role of genetics in Alzheimer’s and related brain disorders. It also opens up new possibilities for studying the molecules involved and potential targets for treatment of this devastating disease.

References:

1. https://newatlas.com/science/gene-study-alzheimers-disease-risk-immune-nature/
2. https://www.nature.com/articles/s41588-022-01024-z