Abstracts

Rationale: Genetic testing for epilepsy is rapidly moving into the clinical arena. Understanding of genetic testing preferences and the factors associated with them is essential in order to provide services likely to be utilized by patients. We surveyed individuals from families with multiple affected individuals to gauge their preferences for genetic testing under four different scenarios defined by clinical utility of the test and penetrance of the genetic variant evaluated in the test.Methods: We are currently carrying out a detailed survey of previous participants in genetic research on the epilepsies, to assess the psychosocial impact of having epilepsy themselves or in their families, beliefs about epilepsy genetics, and interest in genetic testing. The survey will target more than 1,000 adults who are members of 115 families containing multiple individuals with epilepsy (average 4 affected per family). Among 164 participants contacted so far, 144 (88%) have agreed to participate. Here we report preliminary results on 80 individuals (28 with epilepsy, 52 unaffected relatives) who completed the survey as of June 2013. The survey described four different scenarios defined by penetrance ( everyone with the genetic change develops epilepsy vs. only half of those who test positive will develop epilepsy ) and clinical utility of a positive test ( knowing you have the genetic change would improve your medical care (for example, by helping your doctor choose better treatments or reducing the need for other tests), vs. knowing you have the genetic change would have no effect on your medical care. For each scenario, participants were asked whether they would want testing, with four response categories: definitely no, probably no, probably yes, definitely yes.Results: In the 100% penetrance scenario, the proportion of participants who said they would probably or definitely want testing was 84% for a test with clinical utility and 69% for a test without clinical utility (p=0.007, McNemar s test). The scenarios with 50% penetrance were very similar to those with 100% penetrance (with clinical utility 84%, without 65%). For all four scenarios, individuals with epilepsy were more likely to want testing than their unaffected family members (e.g., 100% penetrance with clinical utility: 96% vs. 76%, p=0.024). Testing preferences were not associated with other investigated predictors: sex, age, education, religious preference, religiosity, and causal attribution of epilepsy to genetics.Conclusions: These results indicate a high preference for genetic testing among individuals with epilepsy, particularly when the test is expected to impact clinical care. Clinical utility is a stronger predictor of genetic testing preference than the penetrance of the genetic variant evaluated in the test. In families with multiple individuals with epilepsy, genetic testing preferences are lower among unaffected than affected individuals. This research was supported by R01 NS078419.