• genetic testing;
  • protein C deficiency;
  • psychology;
  • risk perception;
  • screening;
  • thrombophilia

Summary. Background: Little research has been performed regarding the psychological consequences of knowing that one is at an increased risk for venous thrombosis. Objectives: The aim of this study was to explore attitudes toward genetic testing for protein C deficiency. Methods: Questionnaires about genetic testing attitudes, dispositional anxiety, risk perception, and thrombosis-related worry were completed by 168 asymptomatic members of a North-American kindred with a high incidence of heritable protein C deficiency conferring a high lifetime risk of venous thrombosis. A total of 76 subjects (45%) had not been tested for protein C deficiency before participating in our study whereas the other 92 subjects (55%) had been tested prior to filling in the questionnaire, of whom 34 people had protein C deficiency, while 58 did not. Results: Family members with protein C deficiency perceived a higher risk of suffering venous thrombosis and scored higher on thrombosis-related worry than family members without protein C deficiency. Participants who had not been tested did not report excessive thrombosis-related worry. Participants with protein C deficiency reported a belief in the psychological and health benefits of testing, and felt that they experienced low psychological distress following the genetic test. High psychological distress following the test was related to dispositional anxiety and thrombosis-related worry. Participants without protein C deficiency were relieved after finding out that they did not have the deficiency. Conclusion: There seem to be few negative psychological consequences of knowing that one is at an increased risk for venous thrombosis, except in vulnerable individuals.