Diagnostic genetic testing for a fatal illness: the experience of patients with movement disorders

While neurologists encountered the social and ethical concerns associated with diagnosing incurable genetic diseases long before direct DNA testing became available, the increased availability of these tests has magnified these concerns. Most research has focused on the implications of testing asymptomatic individuals; research on the experience of patients with symptoms of heritable conditions is lacking, leaving an ambiguity about their needs with regard to genetic counseling, whether it involves professional counselors or physicians. Here, we investigate the meaning that patients with chorea and ataxia symptoms ascribe to potential or actual DNA testing and explore how patients diagnosed with Huntington's disease or genetic ataxia experience the social, economic and familial implications of a genetic diagnosis. Data come from 27 neurology consultations and 27 in-depth interviews with patients. We found that most view an actual or potential genetic diagnosis as providing relief from uncertainty about their health status. While for some a genetic test can be very similar to other types of procedures aimed at confirming or ruling out a diagnosis, for others (e.g. early symptomatic patients), the implications of diagnostic genetic testing are similar and sometimes amplified when compared with those of predictive testing. Through a case study approach, we identify several expectations and adverse reactions. These include unrealistic hopes that a test will yield a diagnosis leading to treatment, uncertainty about the meaning and reliability of a positive test, and distress upon learning that one has a lethal genetic condition that has already progressed. Even if molecular genetic testing is similar in many respects to prior diagnostic procedures, the many ethical and social issues that have been identified in the context of predictive testing also apply to diagnostic testing. At the same time, concerns specific to symptomatic patients should be considered.