Genetic testing confirms the presence or absence of genes associated with the development of various diseases. Early detection of these genes sometimes enables physicians to recommend interventions that can help to delay onset of disease or prevent the most serious symptoms. The downside, however, is that many of the diseases that are detectable through genetic testing have no treatments or cures. This creates serious ethical and other considerations about when and how such tests should be administered. Dr. Susan Cox is studying the potential benefits and harms of using genetic information to diagnose, treat and prevent two common and devastating chronic diseases: autosomal dominant polycystic kidney disease (ADPKD) and rheumatoid arthritis (RA). Increased availability of genetic screening for ADPKD may have implications for routine screening of people at risk for the disease and for assessing potential kidney donors. The discovery of a gene influencing the severity of some forms of RA may prove to be clinically useful in tailoring drug therapies to persons diagnosed with the condition. Dr. Cox is documenting and comparing perspectives on these developments from patients, families, health care professionals and non-profit agencies. She will use this information to develop criteria for the appropriate use of genetic information in the diagnosis, treatment and prevention of ADPKD and RA. Results from the study will also be relevant to other genetic and hereditary diseases.