[Huntington disease: presymptomatic testing, prenatal diagnosis, preimplantation genetic diagnosis experience]

Presymptomatic testing for Huntington disease has been available for 15 years. The possibility of determining the genetic status of an at-risk person for the disorder which runs in his or her family raises questions because of the absence of preventive treatments. In addition, being carrier does not allow to determine when the disease starts and how it will evolve, impairing the possibilities of planning the future. A pluridisciplinary approach to predictive testing with care before, during and after the test taking into account the medical, social and psychological aspects of the disease is good practice. At the present time, only a minority of at-risk individuals request presymptomatic testing and almost 50% do not pursue until the results. The consequences of the test may be harmful, more frequently after an unfavorable than after a favorable result. Motivations and the outcome in terms of request for prenatal testing after a carrier result are known today and the number or prenatal testing remains very limited. Preimplantation genetic testing is an alternative for couples who knows or do not their own genetic status. We report our experience in two French centres: Paris for presymptomatic and prenatal testing and Strasbourg for preimplantation diagnosis.