[No Magic Bullet: Genetic Diagnostics and Predictive Testing].

The enormous increase in knowledge about the genetic basis of human diseases, combined with the rapid development of genetic techniques, has led to the possible use of genetic tests in medical diagnostics to a degree previously unknown. In addition, predictive genetic diagnostics has the aim of identifying hereditary disease risks in healthy individuals in order to take precautionary measures. However, the assessment of genetic findings is still subject to numerous problems. In particular, in the case of disease prediction, only probability statements can be made since endogenous and exogenous factors influence the penetrance and expressivity of genetically determined diseases.