[Genetic testing].

The first genetic tests started to be developed about twenty years ago. Their initial applications were limited to genetic counselling and prenatal diagnosis of a few hereditary diseases. Technological progress and the identification of genes responsible for many hereditary diseases have led to their development and diffusion. They have become a nearly irreplaceable tool for the diagnosis of hereditary diseases. In the future, their indications should increase when genes implicated in multifactorial diseases are progressively identified. The impact will probably be particularly important in cardiology because most cardiovascular diseases are multifactorial. The first predisposing factors (factor V. prothrombin...) for a predisposition to thrombosis are now daily genetic investigations. In parallel, the progress in pharmacogenetics should enable everyone to have appropriate qualitative and quantitative treatment according to their genetic makeups, which should improve both efficacy and safety. In order to face up to the exponential increase in demand for the genetic tests which will result from these advances, the laboratories should have new high speed, powerful and economic equipment. DNA microchips, which are currently under development could, at least initially, provide a solution to this problem. It is now certain that genetic testing will become routine and, in time, it will be used massively in both hospital and community medicine.