Introduction. In the group of risk at people with COVID-19 there are persons with the such chronic diseases: heart-vessel system; respiratory system; endocrine system; oncologic diseases; immune-deficit states; patients with kidney insufficiency. For every disease there is the concrete set of genes the mutations of which multiply the risk of development of illness. Determination of DNA of sick and healthy people resulted in determination of the genes, related to the diseases which arise up at COVID-19. At persons having by had COVID-19 with the certain disease, with the high stake of probability took place points mutations in certain genes. These people can be brought in a teaching sampling «sick», in a class «healthy» persons are brought in with the negative result of PCR. Purpose of the article. On the basis of teaching selections to develop the effective methods of determination of groups of risks of diseases which COVID-19 accompanies. Results. We consider that genes in a left table column are signs for Bayesian procedure. Work of procedure is executed on the basis of count of amount of mutations or their absence in the teaching selections of classes «sick» and «healthy». We correlate the explored person in that class «sick» and «healthy», for which result of procedure higher. Conclusions. Determination of DNA of sick and healthy people resulted in determination of the genes related to the concrete diseases, including with the diseases which arise up at COVID-19. It is shown that the presence of points mutations in the genes of DNA of man results in the certain disease. On the basis of Bayesian procedure of recognition it is possible effectively to determine the groups of risks of diseases which COVID-19 accompanies. Keywords: determination of DNA, the points mutations, Bayesian procedure of recognition.