[Bourneville's tuberous sclerosis].

Among the group of hereditary histodysplasia, Bourneville's tuberous sclerosis demonstrate original and important place. Its clinical and histopathological polymorphism make more difficult the diagnosis because many symptoms are non specific and/or appeared at different age of life. The variability of the expression and of the penetrance are a very serious unpeachement for the genetic counselling. A recent reevaluation of several series of case reports seems to demonstrate that the frequency of new mutations has been probably surestimated. The gene location in 9q3-4 is quite certain and will induce soon the possibility of a more efficient prenatal diagnosis. The gene action mechanism at the embryonic development is probably correlated with the "oncogene character" of the specific mutation.