"This issue, edited by Anthony Gregg, MD, and Joe Leigh Simpson, MD, is a much needed update of the 2002 issue pertaining to genetic screening and counseling for obstetrician-gynecologists. The purpose of this issue is to assist obstetrician-gynecologists in understanding and applying the concepts of molecular genetics to clinical practice, research, and the provision of health care in the community. In conjunction with genetics counselors, this issue reviews the basics of contemporary prenatal counseling. This issue of Obstetrics and Gynecology Clinics on genetics contains all of the current topics of active clinical relevance." - p. [xiii]