One in five people carry a genetic variant that appears to protect against Alzheimer’s and Parkinson’s, a study suggests.
Analysis of medical and genetic data from hundreds of thousands of people found that having this variant, called DR4, reduced the chances of developing either disease by more than 10 percent on average.
Experts say the discovery could one day lead to a vaccine that could slow or stop the progression of these two common conditions.
An international team, led by Stanford University in California, combined databases from numerous countries to compare the incidence and age of onset of Alzheimer’s and Parkinson’s among people with the variant.
They found that people with the gene were less likely to develop the condition in the first place, and those with it were diagnosed at a later age compared to those without it.
Analysis of medical and genetic data from hundreds of thousands of people found that having a gene called DR4 lowered people’s chances of developing Alzheimer’s and Parkinson’s.
Lead author Emmanual Mignot said: “In a previous study we found that carrying the DR4 allele (variant) appeared to protect against Parkinson’s disease.
“We have now discovered a similar impact of DR4 in Alzheimer’s disease.
“That this protective factor for Parkinson’s would end up having the same protective effect for Alzheimer’s baffled me. The night after we found out about it, I couldn’t sleep.
The researchers also analyzed autopsy data from the brains of more than 7,000 Alzheimer’s patients and found that DR4 carriers had fewer tangles of a protein called tau, as well as a later onset of symptoms, than those who did not carry the genetic variant. .
They said their findings suggest that tau, a key player in Alzheimer’s, may also play some sort of role in Parkinson’s.
The team explained that a vaccine could one day be developed that makes DR4 “work harder” to delay or slow the progression of Alzheimer’s and possibly Parkinson’s.
However, this would only benefit one in five people who carry the genetic variant.
Their findings were published in the Proceedings of the National Academy of Sciences.
What is Alzheimer’s?
Alzheimer’s disease is a progressive, degenerative disease of the brain, in which the buildup of abnormal proteins causes nerve cell death.
This disrupts the transmitters that carry messages and causes the brain to shrink.
More than 5 million people have the disease in the United States, where it is the sixth leading cause of death, and more than 1 million Britons have it.
As brain cells die, the functions they perform are lost.
That includes memory, orientation, and the ability to think and reason.
The progress of the disease is slow and gradual.
On average, patients live five to seven years after diagnosis, but some can live for ten to 15 years.
- Short-term memory loss.
- behavior changes
- Humor changes
- Difficulty handling money or making a phone call.
- Severe memory loss, forgetfulness of close relatives, familiar objects or places.
- Feeling anxious and frustrated by the inability to make sense of the world, leading to aggressive behavior.
- Over time he loses the ability to walk.
- May have trouble eating
- Most will eventually need 24-hour care
Fountain: Alzheimer’s Association