A familial Alzheimer's genetic panel tests APP, PSEN1, and PSEN2 when early-onset disease runs in the family. For a dementia second opinion, it clarifies inherited risk but does not diagnose Alzheimer's by itself. The panel looks for pathogenic variants that cause autosomal-dominant early-onset disease. A second-opinion visit uses that result alongside exams, history, and brain findings to guide next steps.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- What the panel tests
- How accurate is it for your second opinion
- How to prepare records and family history
- What counseling and insurance review to finish first
- What to do after you get results
What the panel tests
The American College of Medical Genetics and NSGC state the panel covers APP, PSEN1, and PSEN2, where a pathogenic variant causes autosomal-dominant early-onset disease joint guideline. These are deterministic genes, not risk markers. A positive result points to a strong inherited pattern.
Reported onset ranges differ by gene. APP often involves ages 40 to 60, PSEN1 ages 30 to 60, and PSEN2 ages 40 to 75. Penetrance is described as complete for APP and PSEN1 and about 95 percent for PSEN2.
How accurate is it for your second opinion
The panel is specific to familial early-onset disease. It does not test every cause of memory loss. It also does not replace clinical diagnosis. The National Institute on Aging explains that diagnosis rests on medical and family history, cognitive and neurological exams, blood work to exclude mimics, plus brain imaging or amyloid and tau biomarkers, not on genetics alone how Alzheimer's is diagnosed.
Genes add context. Exams and biomarkers carry the diagnosis. APOE or other risk-variant testing cannot determine who will develop Alzheimer's. Other biological and life factors also shape onset.
How to prepare records and family history
Bring complete records because files often do not transfer between systems. Ask relatives about age at first symptoms, diagnosis terms used, and any genetic results.
Write a three-generation history if you can. Note parents, siblings, aunts, uncles, and grandparents. Include age at onset, age at death, and cause when known.
- Prior MRI or CT images, not just reports
- Lab results and prior neurology assessments
- Full medication and supplement list with doses
- Dated symptom diary with function changes and examples
What counseling and insurance review to finish first
Pre- and post-test counseling is recommended because results can cause emotional distress and raise discrimination concerns. Counseling also helps with reproductive choices and telling relatives. The Alzheimer's Association cautions against routine testing of healthy people for Alzheimer's risk until the person has counseling on social and economic effects.
Check insurance before testing. The National Human Genome Research Institute notes that the federal law GINA bars health insurers and employers from using genetic information, but it does not cover life, disability, or long-term-care insurance GINA glossary. That gap matters for midlife planning. Ask the clinic how results are stored and shared.
What to do after you get results
Bring the lab report to the second-opinion visit. Ask whether the variant is classified as pathogenic, likely pathogenic, or uncertain. Ask whether relatives should be offered targeted testing or referral to genetics.
If results are negative, ask what remains unexplained. Review vascular risks, sleep apnea, mood, medications, and sensory loss. Confirm whether spinal fluid or PET biomarkers, repeat imaging, or neuropsychological testing would change care.
