[Genetic examinations in health care]

Genes are one of the most important indicators of disease incidence. Almost each diseases results from incorrect function of one or more genes. The disclosure of disease genetically conditioned depends, in many cases, on the effect of a broad spectrum of different environmental factors. Screening tests for carries of defective genes play a key role in the detection of risk for genetically conditioned diseases. Screening tests carried out for many years yielded a very diversified results. Some of them, for example, the screening test for the gene responsible for Tay-Sachs disease, produced good results, whereas results of other tests, like the test for the gene responsible for crescent anaemia, proved to be unsatisfactory. Among genetically conditioned diseases, neoplastic diseases are the subject of particular interest. It is already known that these diseases may be attributed to the accumulation of genetic errors in a normal cell, and that this phenomena applies to certain categories of genes. An analysis of genetic material of persons from the families with higher cancer incidence revealed the relationship between cancer and inheritance of some defective genes. Nevertheless, it should be stressed that the development of cancer is not definitely foregone even if genetic features of cancer disease are detected in a given person. The presence of such features only indicates an inborn or acquired defect (as a result of mutation) that predisposes him/her to illness. A great progress in molecular oncology made during the last years and the development of genetic maps relevant to neoplastic diseases should contribute to the detection of such genetic markers which could facilitate the identification of persons with a higher risk for neoplastic diseases and allow to take relevant preventive measures in due time.