Abstract

Dilemmas arise concerning how to design studies aimed at preventing or slowing Huntington’s disease (HD) in mutation-positive presymptomatic individuals. HD is an autosomal-dominant neurodegenerative disease. Each child of an HD gene expansion carrier (HDGEC) has a 50% chance of inheriting the mutation, but the clinical symptoms typically only appear in middle age. In the absence of clinical symptoms or having obtained predictive genetic testing, such a person is considered at risk for HD. Although genotyping for the HD mutation approaches 100% accuracy, the decision to undergo predictive genetic testing for a debilitating, stigmatized, and ultimately fatal disease is highly personal. Predictive resting rates in HD are <20% in Europe and only 5%-7% in the United States.