Impact of presymptomatic genetic testing for hereditary ataxia and neuromuscular disorders

With the exception of Huntington disease, the psychological and psychosocial impact of DNA testing for neurogenetic disorders has not been well studied.

To evaluate the psychosocial impact of genetic testing for autosomal dominant forms of hereditary ataxia and neuromuscular disorders. Patients Fifty subjects at risk for autosomal dominant forms of spinocerebellar ataxia (n = 11), muscular dystrophy (n = 28), and hereditary neuropathy (n = 12).

A prospective, descriptive, observational study in a university setting of individuals who underwent genetic counseling and DNA testing. Participants completed 3 questionnaires before testing and at regular intervals after testing. The questionnaire set included the Revised Impact of Event Scale, the Hospital Anxiety and Depression Scale, demographic information, and an assessment of attitudes and feelings about genetic testing.

Thirty-nine subjects (78%) completed 6 months to 5 years of posttest follow-up. Common reasons for pursuing genetic testing were to provide an explanation for symptoms, emotional relief, and information for future planning. Thirty-four (68%) had positive and 16 (32%) had negative genetic results. In those with a positive result, 26 (76%) had nonspecific signs or symptoms of the relevant disorder. Forty-two participants (84%) felt genetic testing was beneficial. Groups with positive and negative test results coped well with results. However, 13 subjects (10 with positive and 3 with negative results) reported elevated anxiety levels, and 3 (1 with positive and 2 with negative results) expressed feelings of depression during the follow-up period. The test result was not predictive of anxiety or depression.

Most individuals find neurogenetic testing to be beneficial, regardless of the result. Anxiety or depression may persist in some persons with positive or negative test results. Testing can have a demonstrable impact on family planning and interpersonal relationships. Further studies are needed to assess the long-term impact of such testing.