The value of genetic counseling evaluation of egg donors

Abstract

Objective: This study addresses the importance of obtaining and evaluating a 3-generation pedigree during the egg donor selection process. Design: The study compiled the reported family history from egg donors obtained during genetic counseling sessions. Materials and Methods: The patients used in this study were potential egg donors referred for genetic counseling for family history evaluation and discussion of genetic screening to determine their suitability as egg donors. All donors were seen by either active candidate or board certified genetic counselors during either telephone or face to face counseling sessions. The genetic counselors obtained family history data through a combination of a genetic family history and pregnancy questionnaire and the construction of a three-generation pedigree. All family history data was entered into a clinical database. Results: A total of 152 egg donors were included in the current study. 34% (52) of the donors reported no significant family history. 66% (100) of the donors reported a total of 238 relatives with conditions that could pose a genetic risk for the donor or for future offspring. Medical histories were divided into five sub-categories: physical birth defects, developmental delay, Mendelian disorder, mental illness and common adult-onset disorders. There were 14 (0.5%) relatives reportedly affected with a physical birth defect, including congenital heart defect and cleft lip and/or palate. The presence of a physical birth defect such as congenital heart defect or cleft lip and/or palate could be associated with a risk for a syndrome such as chromosome 22q11 deletion. There were 17 (0.7%) relatives reportedly affected with some type of developmental delay, including mental retardation, autism and Down’s syndrome. A history of autism and mental retardation such as that reported in a half brother or uncle increases the risk to the donor for conditions including fragile X syndrome. There were 5 (0.2%) relatives affected with a Mendelian disorder, including dwarfism, color-blindness and sickle cell anemia. There were 14 (0.5%) relatives affected with mental illness, including schizophrenia and bipolar disease. Finally, there were 152 (64%) relatives with reported family history for common adult-onset conditions including breast cancer, heart disease and colon cancer. The evaluation of family histories with mental illness or common adult-onset conditions such as breast cancer will allow for identification of families at significantly higher risk due to multiple affected family members. Conclusion: The ASMR has established guidelines for “Minimal genetic screening for gamete donors”. These guidelines specifically outline types of disorders that would exclude gamete donors, if these disorders affect the donor or first-degree relatives. The current study outlines the fact that there may be significant family history found in relatives more distant than first-degree that can impact genetic risk for the donor. While these reported histories should not immediately exclude these donors, they require further consideration. The use of genetic counselors will allow for thorough genetic family history evaluation that goes beyond the “minimal genetic screening” required by the ASRM.