[Place and role of genetic counseling]

Genetic counseling is a medical act that consists of informing a patient of his/her risk of developing a genetic disorder, or of transmitting it to his/her offspring, and of informing about diagnostic and therapeutic options, allowing for informed choices. When about a risk to future offspring, genetic counseling is often linked to prenatal diagnosis with elective termination of affected pregnancies, or, in selected cases, to pre-implantation sorting of embryos ("pre-implantation diagnosis"). In a growing number of indications regarding late-onset hereditary disorders, like Huntington's chorea or some hereditary cancers, genetic counseling aims at optimizing medical prevention, or at allowing patients to make life choices which they deem appropriate. The coming years will witness the blossoming of tests allowing for medical provisions based on the genome ("predictive medicine") in frequent, multigenic disorders, or allowing to target drug therapies to the biochemical individualities of patients (pharmacogenetics). The reliability of predictions will however be limited by the role of environmental and stochastic factors involved in the development of virtually all genetic or biochemical traits.