EMOTIONAL AND FUNCTIONAL IMPACT OF DNA TESTING ON PATIENTS WITH SYMPTOMS OF HUNTINGTONS-DISEASE

The potential impact of DNA testing on asymptomatic subjects at risk f or Huntington's disease (HD) has been addressed by numerous studies, b ut the effect of revealing the genetic results to patients with a clin ically established diagnosis of HD has not been previously evaluated. We studied 36 patients, with equal distribution of men and women, mean age 53.9 (SD 12.3) years (range 25-76) and mean duration of symptoms of 11.2 (SD 7.7) years (range 2-33), whose clinical diagnosis of HD wa s confirmed by expanded CAG repeats (>40). Coping strategies and depre ssion levels were assessed before the results of DNA testing were impa rted. The assessments were repeated two weeks and three months after t he results were explained to the patients and their relatives and were compared to the baseline assessments. This group of HD patients was c ompared with 10 patients who had similar symptoms but the diagnosis of HD was excluded by normal CAG repeats (<30). Although some patients w ith HD expressed a subjective reaction to the positive result (four we re ''surprised'', one was ''frustrated'', and one ''devastated''), the re were no differences in any psychological scores including Beck Depr ession Inventory, functional capacity, symptom interference, independe nce scale, and other measures of mood and behaviour two weeks and thre e months later. Similarly, no change was noted in any of these measure s in the non-HD group. These results suggest that mood and coping stra tegies are unaffected by DNA confirmation of diagnosis in symptomatic patients with HD.