A new method for predicting Alzheimer's disease

The risk of Alzheimer's disease can be assessed using nucleotide substitutions

Anna Stavina, XX2 century (based on the materials of UC San Diego: Genetic Assessment Developed to Determine Risk for Age-Associated Alzheimer's Disease – VM).

Scientists have developed a new genetic test that allows you to predict at what age a person will develop Alzheimer's disease. When creating a forecast, 31 genetic markers are used. People who scored high in this screening test may be diagnosed with Alzheimer's disease much earlier than those who received low scores. During the study, 10% of those tested who were in the highest risk group fell ill more than three times more often than those who were among the 10% with the lowest risk. In addition, Alzheimer's disease in at-risk volunteers developed more than 10 years earlier.

Rahul Desikan from the University of California at San Francisco (University of California, San Francisco), who led an international group of scientists, reported that the new test can be used to calculate the individual risk of developing Alzheimer's disease. At the same time, the age of the test subject and the data of genetic analysis are taken into account.

The so-called "polygenic risk scale" was developed on the basis of genetic information collected from more than 70 thousand people, among whom there were both patients with Alzheimer's disease and healthy people.

It is known that genetic factors play an important role in the development of Alzheimer's disease. A quarter of patients with this diagnosis had cases of the disease among close relatives. Scientists have already established that the probability of developing Alzheimer's disease is associated with the gene encoding apoprotein E (ApoE). The presence of two copies of the gene associated with a high risk increases this probability of getting sick by 12 times.

When developing a new test, a different approach was used. Scientists have suggested that, in addition to the ApoE gene, there are thousands of genetic variations, each of which affects the risk of developing Alzheimer's disease only to a small extent. However, their combined impact can be very significant.

The researchers selected about 2,000 single-letter variations of the genetic code, also known as "nucleotide substitutions." Then, sorting them by the degree of influence on the risk of developing Alzheimer's disease, the scientists left 31 most significant replacements in the list. The new test was then tested on an independent group of patients. In trials, he demonstrated the ability to accurately predict the risk of developing the disease for an individual patient.

James Pickett, head of the Alzheimer's Society Research Department, commented on the new screening test: "Preventing the development of dementia symptoms is the holy Grail of research on Alzheimer's disease. But in order for prevention to be successful, we need to learn how to identify people who are most likely to develop this disease. The new approach turned out to be quite accurate in terms of risk prediction. It allowed us to estimate the probability of developing Alzheimer's disease in a patient in the next year. However, further trials of this method in mixed populations outside the United States are needed."

The results of the study were published in the publication PLOS Medicine (Desikan et al., Genetic assessment of age-associated Alzheimer's disease risk: Development and validation of a polygenic hazard score – VM).

Portal "Eternal youth" http://vechnayamolodost.ru  23.03.2017