Dementia
Largest genetic study of Alzheimer's finds 48 new risk regions in DNA
Researchers studied DNA from about 2.8 million people and linked 127 regions to Alzheimer's risk. They say it guides future research but does not mean a gene test can predict who gets the disease.
Key facts
- A Nature study linked 127 DNA regions to Alzheimer's risk, 48 of them new.
- Researchers say it is not a basis for predicting any one person's risk.
What happened
An international team led by Vrije Universiteit Amsterdam published what it calls the largest genetic study of Alzheimer's disease to date in the journal Nature on October 28. The researchers pooled genetic data from about 2.8 million people, including 183,620 people with Alzheimer's, drawn from 30 research groups.
They found 127 regions of human DNA linked to the risk of Alzheimer's, and 48 of those had not been tied to the disease before. Many of the findings point to microglia, the brain's immune cells, which help clear away damaged material. The team also found signals in several specific types of nerve cells and in processes involving amyloid, a protein that can build up in the brain.
The researchers estimate that common genetic differences together explain about 16% of the variation in Alzheimer's risk between people, roughly three times earlier estimates of about 5%. They stressed that this is a population-level figure. It does not mean a person's risk is 16% genetic, and it does not mean a genetic test can tell whether someone will develop the disease. Age, environment and other factors also matter, and follow-up research is needed before any of these findings lead to treatments.
What it means for families
This is basic research that may shape future drug studies. It does not change how Alzheimer's is diagnosed or treated today.
For example: a family with several relatives who had Alzheimer's may wonder about testing. The researchers say risk models like theirs are, for now, mainly a research tool.
Questions about family history and memory changes are best raised with a primary care doctor.
What this means in New York: families worried about memory changes can contact the state's Alzheimer's Disease Caregiver Support Initiative programs or NY Connects at 1-800-342-9871 for local help.
What to do this week
- Write down family history of memory problems before a doctor visit.
- Bring up any memory changes at a parent's next checkup.
- Be cautious of tests marketed as predicting Alzheimer's.
Sources
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