This study entitled "Response of a Sample Population with the Deleterious HD allele" (RESPOND-HD) will examine ethical, legal, and social considerations that may affect the experience of persons following genetic testing for Huntington's disease (HD). HD is a genetic brain disease that typically begins in mid-life. Since predictive testing for HD was one of the first genetic tests available for later onset disorders, research in HD has traditionally helped define issues for ethical, legal and social aspects of genetic disorders. As knowledge of the human genome increases, public apprehension concerning the use of such genetic information has grown correspondingly. Although practice standards in medicine generally require that health care decisions (including genetic testing) should be determined by a patient's personal values, it is difficult to assess how to fully inform consumers about predictive testing. Information understood by persons considering having a genetic test should include the clinical validity of genetic tests, availability of effective treatment, access to health care and insurance, legal and social implications of genetic information, and the psychological impact of having knowledge about one's future. Unfortunately, little is currently known about these issues following genetic testing. HD families, in particular, are appropriately concerned about social and legal consequences of being identified with a genetic illness. In this study, comparative qualitative interviews and quantitative data collection via survey and standardized rating scales will be obtained from individuals who have undergone predictive testing for the HD gene expansion. Unlike previous research, the RESPOND sample has undergone predictive testing in the past and data will allow for query of stigmatization and discrimination since receiving news of having a deleterious HD allele. Findings will examine how people perceive possible consequences, choose their behaviors, and make decisions after genetic testing. Data can be used for development of clinical care practices, research protocol, and legal policy. Over 300 persons from the NINDS-funded study entitled "Predict-HD" will be invited to participate in this study. Predict-HD is an ongoing study of biological and behavioral markers of disease in persons with a known gene expansion for HD. Data will be compared with the NHGRI-funded study entitled "PHAROS" which examines persons who are at risk for HD but chose not to undergo genetic testing. This study will be among the first to compare ethical, legal and social experiences of having known genetic risk.