Rationale for Correct Answer
The correct answer is: Take a 3-generation family history with specific attention to neurologic and psychiatric symptoms.
Having 1 or more first-degree relatives (parents, siblings, children) with Alzheimer's disease significantly increases an individual's risk of developing the disease (risk increased by a factor of 1.73). The risk continues to increase with each additional affected first-degree relative (risk increased by a factor of 3.98, 2.48, and 14.77 with 2, 3, and 4 or more affected first-degree relatives, respectively).1 Even if an individual's first- and second-degree relatives do not have AD, having 3 or more third-degree relatives with AD will increase their risk by a factor of 1.43 relative to the general population.1
When a patient requests a test, they should be given the option to proceed with disclosure, delay disclosure, or decline disclosure of the results.1
The American College of Medical Genetics and the National Society of Genetic Counselors do not endorse ApoE testing and advise against direct-to-consumer ApoE testing. If genetic testing is ordered, perform a baseline neurologic and neuropsychological evaluation and assess and review the psychosocial impact of testing on the patient and their family.3,4
References:
1. Cannon-Albright LA et al. Neurology. 2019;92:e1745-e1753.
2. Langlois CM et al. Alzheimers Dement (N Y). 2019;5:705-716.
3. Goldman JS et al. Genet Med. 2011;13:597-605.
4. Goldman JG et al. PJ Parkinsons Dis. 2018;4:19.