Abstract
In most medical practices, advice about the possibility of the recurrence of a genetic disease or a congenital anomaly is usually sought by parents who have already produced an affected child or by prospective parents, one of whom may be affected or has a family history of what may be a genetically determined disease. Such advice is requested not only about the rare genetic disorders but also about fairly common conditions such as epilepsy and diabetes. With a precise diagnosis, a carefully elicited family history, and an adequate understanding of the principles involved, the genetic prognosis can be given in most cases as a probability statement with a high degree of confidence. But further, discussion of the implications of a genetic prognosis must be related to the personal circumstances of the individuals concerned and requires high doctor-patient rapport.