The purpose of this project is to produce several professional articles that identify and analyze the ethical, legal, and social issues that surround screening and altering human embryos, thus helping society and relevant decision-makers come to grips with these issues. Year 1 of the project will focus on embryo screening as a form of negative genetic selection, and its use in screening embryos for transfer based on reasons other than avoidance of severe genetic disease, i.e., for susceptibility mutations, for HLA matching, for gender, and for non-medical traits.