[Bourneville's tuberous sclerosis and genetic counseling. Study of 36 families]

From their own experience, the authors grapple with the difficulties of the genetic counselling in the tuberous sclerosis. They dwell on the necessity of undertaking a very full assessment in the parents of the apparently isolated cases. It includes skin examination, fundoscopy, cranial CT scanning, renal imaging and echocardiography. After these investigations which may need to be done to make or to exclude the diagnosis, it will be possible to quantify new mutations. Nevertheless the exceptional description of pedigrees with incomplete penetrance cannot be forgotten for the genetic counselling. It is likely however that most of these problems will not be resolved until accurate genetic markers are obtained.