Predictive testing for Huntington's disease: risk perception, reasons for testing and psychological profile of test applicants.

In the Center for Human Genetics in Leuven, predictive DNA-testing for Huntington's disease is available as a clinical service since November 1987, initially by DNA-linkage and since mid 1993 by direct mutation analysis. The multidisciplinary approach as well as the detailed test protocol are described. The present paper gives a sociodemographic description of the test applicants, their subjective evaluation of the risk and their motives for requesting the predictive test. Major attention is paid to the personality profile of the applicants who proceeded with testing. Psychometric testing revealed that this group of test applicants did not differ significantly from the general population for most characteristics and even had a number of more positive characteristics e.g. a higher ego-strength. The latter may reflect a self-selection of a more resourceful and emotionally healthier subgroup of at-risk persons. Nevertheless psychological evaluation also has identified a number of applicants with extremely high anxiety levels and other problems, who needed extra pretest and posttest counseling. The relatively high number of withdrawals from the test programme is another indication of the importance of adequate pretest counseling.