ABSTRACT
Huntington’s disease (HD) is often used by clinical geneticists as a paradigm for other late-onset inherited disorders, including the many neurodegenerative conditions that have a genetic aetiology. This is partly because HD is among the most common and unpleasant diseases seen in the genetic counselling clinic, and amply illustrates the practical, psychological and social problems facing those who are at risk of inheriting one of these disorders. However, HD was also the first adult-onset human genetic disease for which the responsible gene was initially localized, and then identified, by molecular genetic research methods. Consequently, the practical, ethical and genetic counselling problems arising from the clinical application of this new knowledge in the form of predictive and prenatal genetic testing were first worked out for HD, and the lessons learned have subsequently been modified and applied to other disorders with similar clinical and genetic characteristics. Much of this chapter therefore follows the same convention and focuses on a discussion of the genetic counselling issues associated with prenatal testing for HD, but there are many similar, if much less common, late-onset inherited neurodegenerative disorders for which the same general principles apply.
