Final answer:
A genetic test to identify Alzheimer's risk has the advantage of early detection but also brings the disadvantage of causing psychological stress from knowing one's increased susceptibility.
Step-by-step explanation:
An advantage of a genetic test that would identify genes in individuals that increase their probability of having Alzheimer's disease is the potential for early detection and preparation. Individuals with a higher genetic risk can make lifestyle changes, focus on brain health and possibly participate in early intervention treatments. However, a significant disadvantage is the psychological burden of knowing one’s increased susceptibility, which could lead to stress or anxiety, and not all individuals who possess these genes will develop Alzheimer’s, which might lead to unnecessary worry.
Moreover, the reliance on memory for the test's predictions might be problematic. Since the test results are based on probability, they do not necessarily reflect a typical 24-hour observation period of a person's life. This reliance on memory can also relate to the psychological impact of the test, as constant remembrance of a genetic predisposition might influence one’s quality of life.