Genetic variants that protect against Alzheimer’s disease have been identified by scientists.
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The research builds on previous studies in mice and rats, which suggested inhibiting the function of these proteins might be protective against Alzheimer's disease, but this is the first time such an effect has been demonstrated in people.
"These results are quite encouraging. It looks as though when naturally-occurring genetic variants reduce the activity of tyrosine phosphatases then this makes Alzheimer's disease less likely to develop, suggesting that drugs which have the same effect might also be protective," said the study's lead author, Professor David Curtis (UCL Genetics Institute). In this study, scientists analysed DNA from 10,000 people: half with Alzheimer's disease and half without.
In total, researchers examined all DNA sequence variants in over 15,000 genes, including over one million individual variants, in order to identify genes in which damaging variants were more common in people with or without Alzheimer's disease.
Researchers found that Alzheimer's disease risk is lower in people with damaging variants in a particular class of genes, which code for tyrosine phosphatases. The researchers say the findings suggest that drugs which have the same effect might also be able to reduce the risk of Alzheimer's. Professor Curtis points out there are already some drugs which act on tyrosine phosphatases but they have not yet been tested in clinical trials.
"Here's a natural experiment in people that helps us understand how Alzheimer's disease develops: as some people have these genetic variants and some don't, we can see that the impact of having particular variants is a reduced likelihood of developing Alzheimer's disease," Professor Curtis added.
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The study also found suggestive evidence to implicate a gene not previously known to affect Alzheimer's risk, called C1R. The gene is known to affect periodontal Ehlers-Danlos syndrome, a disease involving chronic gum inflammation. Some previous research suggests that gum infections may increase the risk of Alzheimer's disease, so Professor Curtis speculates there may be a mechanism whereby genetic variants in C1R lead to some degree of gum disease, which in turn predisposes to Alzheimer's disease.
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"Finding DNA variants which modify the risk of Alzheimer's disease is useful as it may help us develop drugs which target the same proteins. Simultaneously, researchers at UCL and across the globe are finding ways to detect the earliest stages of Alzheimer's disease, before it causes any problems. As our understanding improves, there may be opportunities to intervene with treatments to prevent the disease from progressing," Professor Curtis said.
Professor Curtis, honorary professor at the UCL Genetics Institute and at Queen Mary University London, conducted the study with a team of undergraduate students in the UCL Genetics Institute. The data was generated by an international collaboration, the Alzheimer's Disease Sequencing Project.
Source-Eurekalert