Understanding genetic testing for Alzheimer disease: medical and epidemiological background.

To assess the potential benefits and risks of genetic testing for Alzheimer disease (AD), patients and families, health care providers, and policymakers must understand the medical and epidemiologic aspects of the disease. This paper provides a brief overview of the symptoms, progression, and etiology of AD, as well as of the prevalence and incidence of the disease. The established and the controversial risk factors thought to be associated with the development of AD are described. Current methods for diagnosing and treating AD are also reviewed.