A barometer of the time is the growing interest and concern about genetic diseases and genetic screening programs. Science writer David Hendin and Joan Marks, Director of the Human Genetics Program at Sarah Lawrence, nicely summarize the current state of the art in a book that addresses the reader as potential parent. They begin with a survey of statistics to illustrate how widespread are genetic defects--as causes of miscarriages, infant mortality, and mental retardation. Next they review the nature and give examples of recessive, dominant, and sex-linked disorders, as well as chromosomal defects (as in Down syndrome, for example). Because so little is known or understood about genetic counseling, the authors take pains to describe what this new medical discipline is all about: who does it, who needs it, what are typical scenarios. Most telling are the sad accounts of parents who might have benefited from counseling had it been available along with some of the newer tests for carriers or for examination of fetal tissue. The psychological problems of anxiety, guilt, isolation, rejection, resentment all too often follow the birth of a defective child. Good genetic counseling should deal with these problems as well as provide basic information on inheritance. Concluding chapters take up the moral and ethical: issues raised by new screening techniques. Like Philip Reilly (p. 1250), the writers believe that public education and complete information are mandatory if individuals are to make free choices. Appendices give sources of information on specific diseases and state-by-state lists of genetic counseling and treatment centers. Good basic information here, and a harbinger of things to come.