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...