Potential impact of a predictive test on the gene frequency of Huntington disease.

Fifty-five individuals at 50% risk of inheriting Huntington disease (HD) were given in-depth structured interviews to survey attitudes toward use of a predictive test and to assess the possible impact of such a test on the number of gene carriers born. Three-quarters of the sample said they would take predictive test. Given a positive predictive or prenatal test, the number of individuals choosing to have children is reduced from 80% of the total sample to 42%, or by almost one-half. The large proportion of at risk individuals who say they would use a predictive test underscores the importance of developing guidelines for its administration prior to implementation.