Find the ancestors and choose a diet

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What is a genetic test and why is it needed?

This is an analysis of DNA with which you can learn your own characteristics: from an ethnic group to a predisposition to any disease. It also helps to identify mutations in DNA or chromosomes of a person who can either not affect health and make a person a healthy carrier of the disease.

Also, such tests are made when planning pregnancy. This helps to find out the likelihood that a child can manifest a disease. For example, in the case of cystic fibrosis ( diseases, as a result of which mucus that interferes with breathing accumulates in the lungs ), if the mother and father have one “defective” gene, with a probability of 25%, their child will be born with this disease. The risk of chromosome anomalies or genetic vices also shows the screening of the first trimester, but the test helps to evaluate risks even before pregnancy.

What do private clinics offer?

The Age of Consumer Genetics-Direct-to-Consumer Genetics- began in the late 1990s. Genetic tests focused on conditionally healthy people were acquired in the late 2010s.

Now some private clinics offer tests so that the client can find out his origin or get recommendations for nutrition and his physical exertion. In Russia, such services cost from 24 to 140 thousand rubles.

Usually genetic tests are rented at home. You will be delivered a special test tube, which needs to be filled with saliva, after which the courier takes it to the clinic, and the results can be found in your personal account. Often, after the test, you can take a free consultation of a geneticist who will tell you about the results and, if necessary, advise the examination.

More tests can help analyze the effect on the body of various drugs. For example, the CYP2D6 gene encodes ( contains information about which particular protein option is synthesized from amino acids in the body ) of the same name. It affects the absorption of some antipsychotics, antidepressants and antiarrhythmic drugs (drug control drugs).

As for suitable physical exertion or nutrition, the results of tests will not answer the question of whether it is worth doing figure skating or swimming whether to try vegetarianism or not. The test will help determine the risk of tendon injuries and ligaments and evaluate the endurance of the body. This also largely depends on the genes: for example, changes in COL5A1 (contained in collagen) and TNC were associated with scientists with an increased risk of injuries of the Achilles tendon.

Tests will also not select the perfect diet, but can, for example, identify mutations in genes that regulate the absorption of lactose and gluten .

I heard that with the help of tests you can find out your roots. This is true?

The search for ancestors or a definition of nationality is a common request to genetic tests. But geneticist doctors do not have the concept of “nationality”, there is only a “population”-a group of people who have lived for a long time in the same territory and were partially isolated from other groups.

“Each population has its own set of mutations,” says Genetics Oksana Efremova. “If a person passes a test to find out nationality, then he can only, as a percentage, find out, which genotype of which population is larger and which is less.”

The genotype of populations is taken from a database that is at the disposal of the laboratory. Crimeable bases are used by forensic scientists: they allow them to search and compare DNA samples from the scene with the existing data. And geneticist doctors compare the test results with genotypes of different populations and reveal similar patterns.

At the same time, companies have to balance between the accuracy of the analysis and the need to satisfy the client’s requests, says genealogue, founder of the Genealog Rocks Bureau, Marina Brizhova: “The more accurately the company determines nationality, the higher the probability of error. The lower it makes this detail, the more the client is dissatisfied: he wants specifics. ” That is, the more accurately the place of the origin of the ancestors is indicated - for example, the South Moravian Territory, and not just the Czech Republic, the higher the probability of an error.

Most accurately the test can determine belonging to isolated populations - the peoples who lived for a long time, having little intersecting with others. These include, for example, the indigenous peoples of Siberia or the Far East. To recognize the genotypes of already mixed European nationalities - British, Germans, Frenchmen and so on - much more difficult.

If you want to find relatives, you need “coincideners”-people who are potentially our relatives according to the results of the DNA test. “Councils can be found through the clinic databases in which you passed the test. A prerequisite - a person had to do a genetic analysis in the same medical center and consent to that potential relatives could contact him. Otherwise, you will not know about him, ”says Brizhtova.

It is not enough for the repatriation of one genetic test - it is important to prove kinship with citizens of a particular country. In the case of Israel , for example, a documented relationship with a Jew (grandparents, father or mother) or marriage with a citizen of the country is required. At the same time, the DNA test may ask, for example, to prove the Jewish roots of a child born outside Israel, or if the reprian is a weak evidence base.

Experts interviewed by Cold, the opinion that tests for selecting a diet or search for their roots are more likely entertaining. Also, one test is not enough to diagnose the risk of obesity or hypertension. If a genetic analysis showed the risk of any disease, it must be discussed with a specialized specialist who will prescribe additional research.

Is it possible to pass such tests for free?

As a rule, they are not included in the compulsory medical insurance, but there are exceptions. For example, in the direction of the doctor, you can take free BRCA testing for determining mutations in the BRCA-1 and BRCA-2 genes (genes that increase the risk of developing breast cancer and other cancer).

Even in St. Petersburg, when marriage, the “ Certificate of Newlyweds ” is issued: it includes a free consultation of a geneticist for pregnancy planning.

There are also charitable foundations - for example, the " genome of life ." With the conclusion of a geneticist and a direction for testing, you can leave a request on the site and make tests for free.

What results of genetic tests can be believed?

If we talk about tests for identifying pathologies, when they are conducted, there are protocols that are followed by geneticists-if everything is done correctly, the test results can be considered reliable. However, in each analysis there are “blind zones”: for example, a geneticist in the protocol analyzes 20 cells, and if not one of them was detected by pathology, then the conclusion will indicate that there are no risks of the manifestation of the disease. Purely theoretically, pathology can be found in the 21st or 30th cell, and the reliability of the analysis will decrease.

At the same time, even if the test shows that the risk of any disease is great, this does not mean that it will certainly arise. This is what classifies to the disadvantages of genetic tests. The development of the disease depends not only on genetics, but also on many external factors . For example, Alzheimer's disease can be inherited, but its manifestation depends not only on a genetic predisposition, but also on a human lifestyle. Chronic lack of sleep and stress, for example, increase the risk of this disease.