[Prediction in medicine--genome contra envirome]

Human phenotype is governed by its genotype--a set of genetic information materialized in DNA. Using traditional terminology we speak about a little more than 20 thousands genes that differ in strength to become realized and their effect is modified by a large number of other genes. The result originates from firmly established programmes we obtained from our ancestors. Development and activity of such molecules selected for maintenance, copying and transfer of information i.e. nucleic acids can be followed back to the very origin of the life. Nevertheless the final result is achieved not only by confrontation of the original information with other genetic information but largely also by external influences--environment. Though we are relatively successful in understanding what we have inherited from our parents, our knowledge of environmental factors and their effects on formation of the phenotype is still limited. From this point of view medical prediction has always to be very cautious and interpretations at the probability level must be done by a very experienced and responsible professional.