The specialist neurologist and the "new genetics".

The "new genetics" will require specialist physicians to deal with an increasing number of genetic issues. Huntington disease (HD) is a rare single gene adult-onset fatal neurodegenerative disorder. It provides a model to illustrate the role of the specialist physician in the new genetics. DNA testing options in HD include diagnostic DNA tests to confirm a provisional diagnosis, and predictive or presymptomatic DNA tests to determine whether disease will develop in an at-risk individual. The specialist physician is well positioned to interact with the genetics services by providing in-depth knowledge of the clinical implications. This will become particularly relevant as the more complex multifactorial disorders (eg, Alzheimer disease) are understood at the DNA level. For optimal use of the new genetics, a team approach is essential to ensure that all areas of expertise are covered.