A familial Alzheimer's genetic panel tests three genes — APP, PSEN1, and PSEN2 — that cause early-onset, dominantly-inherited Alzheimer's disease. It's typically ordered when a person's dementia symptoms appear young (often before age 65) and a parent or sibling has had the same diagnosis. This kind of testing differs from the commercial APOE tests that estimate general Alzheimer's risk. A familial panel looks for a specific, rare genetic cause that runs in a family and explains why a disease usually seen in older adults is instead showing up in someone's 40s or 50s.
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 does this panel actually test, and when is it ordered?
- How often does testing actually find a cause?
- What does the test cost, and will insurance cover it?
- Why genetic counseling comes before and after the test
- What to ask for at a referral
What does this panel actually test, and when is it ordered?
The panel sequences APP, PSEN1, and PSEN2, the three genes known to cause autosomal-dominant Alzheimer's disease. A joint practice guideline from the American College of Medical Genetics and Genomics (ACMG) and the National Society of Genetic Counselors states that testing may be considered for someone with a personal and family history consistent with early-onset, dominantly-inherited Alzheimer's — and that informed consent and genetic counseling are required parts of the process, not optional add-ons, according to the ACMG/NSGC joint guideline cited in Paramount's medical policy. A physician has to order the test.
It is not something a patient or family member can request directly from a lab, which is also why the first real step after noticing early symptoms is usually a referral to a neurologist, memory clinic, or genetic counselor rather than a direct lab order. Not every panel on the market is the same panel. Some labs test only the three familial genes; others bundle in dozens of additional dementia-related genes. According to a University of Wisconsin presentation by genetic counselor Abigail Freeman, dementia gene panels range from 3 to more than 90 genes depending on which lab and panel version is ordered, which affects both what gets found and what it costs.
How often does testing actually find a cause?
In families where a dominant inheritance pattern is already suspected — meaning Alzheimer's has appeared across multiple generations, often starting before age 65 — the three-gene panel identifies a causative variant in roughly 60% to 80% of cases, according to ARUP Laboratories' test compendium. The three genes don't contribute equally. PSEN1 accounts for about 20% to 70% of early-onset familial cases, APP for 10% to 15%, and PSEN2 for about 5%, per the same ARUP data.
That spread matters for interpreting a negative result: a family with a strong, unmistakable pattern of early-onset Alzheimer's across generations may still carry a variant the current panel doesn't catch, particularly if it falls outside these three genes. A negative result in a family without a clear dominant pattern means something different — it's far less likely there was a single genetic cause to find in the first place. This is one reason a genetic counselor reviews the family history before testing, so the result can be interpreted against the right baseline.
What does the test cost, and will insurance cover it?
The APP/PSEN1/PSEN2 panel from ARUP Laboratories has a typical patient out-of-pocket cost around $300, though the range runs from $0 to $1,000 depending on insurance, with results back in roughly three weeks, according to the University of Wisconsin DDCN presentation. Coverage is inconsistent, and many families end up paying the full cost themselves. Clinicians at the University of Washington Memory and Brain Wellness Center note that insurers frequently deny these tests outside narrow predictive-testing criteria, meaning symptomatic patients testing to confirm a diagnosis are covered more reliably than healthy relatives testing to learn their own risk.
Insurer policies spell out when they will pay. Blue Shield of California's medical policy covers targeted single-site testing of an asymptomatic at-risk relative only when a close family member already has a confirmed familial variant, and typically requires that the result will inform a reproductive decision, according to Blue Shield of California's genetic testing policy. Blue Cross NC's commercial policy follows the same logic: testing is considered medically necessary mainly when a known familial variant exists in a relative and results will shape reproductive planning, per Blue Cross NC's policy AHS-M2038. In practice, that means a person with symptoms and a strong family history has a more defensible insurance case than a healthy adult who simply wants to know their risk before symptoms appear.
Why genetic counseling comes before and after the test
Testing is never just a blood draw and a result. The ACMG/NSGC guideline calls for professional genetic counseling both before and after testing, a point corroborated by Pathology Tests Explained's overview of PSEN1 testing, and this is especially important for predictive testing of a currently healthy relative who has no symptoms yet. A pre-test counseling session covers what a positive result would mean, what a negative result would and wouldn't rule out, and how either outcome might affect siblings, children, and life decisions.
A post-test session is where the result is explained in the context of the person's actual family history, rather than handed over as a raw lab report. There's also a legal gap worth knowing about going in. The Genetic Information Nondiscrimination Act (GINA) protects against discrimination in health insurance and employment based on genetic test results, but it does not cover life insurance, disability insurance, or long-term care insurance, a gap that genetic counseling materials flag directly when discussing predictive testing, per the University of Washington's dementia genetics presentation. A family member considering applying for long-term care insurance may want to do that before testing, since a positive result could affect future applications for those specific products.
What to ask for at a referral
A few concrete questions make the referral conversation more productive: Bringing a family history timeline to the first appointment — ages of onset, who was affected, and any prior genetic testing in the family — gives the referring clinician and genetic counselor the information they need to decide whether this specific panel, a broader one, or no testing at all is the right next step.
- Which panel is being ordered — just APP/PSEN1/PSEN2, or a larger dementia gene panel — and why that scope fits this family's history.
- Whether the lab's estimated out-of-pocket cost and turnaround time have been confirmed with the specific insurance plan beforehand.
- Whether genetic counseling is built into the referral, or needs to be scheduled separately before the blood draw.
- If the person being tested is asymptomatic, whether the insurer requires a confirmed familial variant in a relative first, since several commercial policies will not cover predictive testing without one.
- How a negative result will be interpreted given the family's specific pattern, since the three-gene panel misses roughly 20% to 40% of cases even where a dominant pattern is strongly suspected.
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