The Bishop Bekkers Foundation, devoted to the welfare of those with mental handicap and to the amelioration and prevention of this and related disabilities, is to be warmly congratulated for sponsoring and organizing the 1986 Inter national Workshop from which the present book is derived. With commendable foresight, the Foundation recognized that genetic aspects of mental handicap were a timely focus for the Workshop and that dramatic biomedical developments and prospects in this sphere have highly significant psychosocial and ethical ramifications. The papers of the 23 contributors in each of these areas, together with an introductory essay and discussion summaries, comprise this volume. Much of the subject matter is inevitably concerned with such sensitive issues as sanctity and quality of life and the - sometimes contrasting and even in conflict - rights and needs of the actually and potentially handicapped, their relatives and society in general. Such considerations, not surprisingly, engender different approaches and viewpoints. The papers in this book reflect this, with the editing attempting to achieve, as far as possible, a coherent and consistent format and not an identical outlook. The perceptions and views expressed in each paper are there fore those of the author concerned and not necessarily those of the editors or of the Bishop Bekkers Foundation."