Surrogate decision making for genetic testing for Alzheimer disease.

Genetic tests are commercially available for the purpose of aiding in the differential diagnosis of Alzheimer disease among patients with dementia. Such patients often lack the mental capacity to consent to or reject such testing. If genetic testing is to be undertaken, it is important legally and ethically to consider who should participate in the decision to test. State law and the patient's previously expressed wishes will determine which individual should serve as the surrogate decision maker. Other family members should be included in the discussion of the decision, and their assent to the surrogate's decision should be sought.