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PubMed This is a summary of 20 peer-reviewed journal articles Updated
Genetics · Autosomal Dominant Alzheimer Disease

The Path to Certainty: Genetic Testing and Diagnostic Tools

At a Glance

Genetic testing for Autosomal Dominant Alzheimer Disease (ADAD) can identify the disease years before symptoms start. Because clinical results become part of your permanent medical record, experts strongly advise securing life, disability, and long-term care insurance prior to getting tested.

The process of diagnosing Autosomal Dominant Alzheimer Disease (ADAD) is different from diagnosing most other medical conditions. Because the disease is caused by a single known genetic mutation, the “diagnosis” can often be made years before any symptoms appear. This creates a unique path for patients, involving a blend of genetic science and intensive emotional support.

Crucial Warning: Insurance and Your Genetic Status

Before undergoing any clinical genetic testing, you must carefully consider how the results could affect your future financial security. While the Genetic Information Nondiscrimination Act (GINA) protects you from being discriminated against by health insurance providers and employers, it does not protect life insurance, long-term care insurance, or disability insurance [1].

If you test positive in a clinical setting, that result becomes part of your permanent medical record. Life insurance companies can legally request these records and use them to deny you coverage.

  • Protect Yourself: It is highly recommended to secure robust life, disability, and long-term care policies before you undergo predictive genetic testing.
  • Anonymous Testing: If you want to contribute to research without risking your insurance, you can participate in observational studies (like the DIAN registry), which keep your genetic status entirely separate from your official medical records.

The Gold Standard: Genetic Counseling and Testing

Testing for ADAD is not a simple blood draw; it is a highly structured emotional journey. Most specialized centers follow a protocol similar to the one used for Huntington’s disease to ensure you are fully prepared [2][3].

  • Genetic Counseling: Before testing, you will meet with a genetic counselor. They help you explore the “why” behind your decision, ensure you understand the insurance implications, and confirm you have a support system in place [4][5].
  • Predictive vs. Diagnostic Testing:
    • Predictive Testing is for people who have no symptoms but know the disease runs in their family. It tells you if you are highly likely to develop the disease in the future [6][7].
    • Diagnostic Testing is for someone who is already experiencing cognitive changes, to confirm if those changes are caused by an ADAD mutation [8].
  • Non-Disclosure Options for Family Planning: Some people choose ‘non-disclosure’ testing (also known as exclusion testing). This applies specifically to IVF and embryo testing, allowing doctors to ensure your future children do not inherit the gene without you ever having to learn your own adult genetic status [9]. (See the Planning Your Family section for details.)

Questions to Ask Your Genetic Counselor

When meeting with your counselor, use these questions to guide the conversation:

  • “How can I ensure my test results are kept out of my general medical record if I choose to pay out-of-pocket?”
  • “If I don’t want to be tested yet, can I still participate in research or prevention clinical trials?”
  • “What psychological support networks do you offer to patients who test positive for a mutation?”

Modern Diagnostic Tools: PET, CSF, and Blood Tests

While a genetic test confirms the cause, other tools allow doctors to see the effect the disease is having on your brain in real-time.

  • Imaging with PET Scans: Positron Emission Tomography (PET) scans use a safe tracer to “light up” specific proteins. Amyloid-PET shows early plaque buildup, while Tau-PET shows tangles and is a stronger predictor of when symptoms will actually start [10][11].
  • Spinal Fluid (CSF) Testing: Doctors look for a specific “signature”—low levels of amyloid (stuck in the brain) and high levels of tau (leaking from damaged cells) [12][13].
  • The New Frontier (Blood-Based Biomarkers): Breakthrough blood tests like p-tau217 are now considered nearly as accurate as a brain scan for detecting Alzheimer’s pathology [14][15]. In ADAD, p-tau217 levels begin to rise significantly up to 20 years before symptoms appear [16].

Avoiding the “Wrong” Diagnosis

Because ADAD starts at a young age, it is frequently misdiagnosed at first. Patients are often incorrectly told they have depression, burnout, or Frontotemporal Dementia (FTD) [17][18]. Definitive confirmation is almost always done through genetic testing of the PSEN1, PSEN2, or APP genes [19][20].

Common questions in this guide

How does clinical genetic testing for ADAD affect my life insurance?
While laws protect your health insurance and employment, clinical genetic test results become part of your medical record. Life, disability, and long-term care insurance companies can use this information to deny coverage, so it is recommended to secure these policies before testing.
What is the difference between predictive and diagnostic testing for ADAD?
Predictive testing is for people with a family history who do not yet have symptoms, showing if they will develop the disease. Diagnostic testing is used for someone already showing cognitive changes to confirm if a specific genetic mutation is the cause.
How are blood tests used to diagnose Autosomal Dominant Alzheimer Disease?
New blood-based biomarkers, like the p-tau217 test, can detect Alzheimer's pathology with high accuracy. In ADAD, these biomarker levels can begin to rise up to 20 years before any noticeable cognitive symptoms appear.
Can I have a child without passing on the ADAD gene mutation if I don't know my own status?
Yes, you can use a process called non-disclosure testing during in vitro fertilization (IVF). This allows doctors to test embryos and ensure your future children do not inherit the gene, without you having to learn your own genetic status.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Do you use a modified 'Huntington’s disease protocol' for genetic counseling and testing?
  2. 2.If I test positive for a mutation, what specific psychosocial support services does your clinic provide for long-term follow-up?
  3. 3.How do you use blood tests like p-tau217 in conjunction with PET scans to monitor my brain health?
  4. 4.What are the most common conditions you rule out before confirming an ADAD diagnosis in someone my age?
  5. 5.Can we discuss 'non-disclosure' testing options if I am primarily interested in family planning?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (20)
  1. 1

    Suicidal ideation is common in autosomal dominant Alzheimer's disease at-risk persons.

    Ng KP, Richard-Devantoy S, Bertrand JA, et al.

    International journal of geriatric psychiatry 2020; (35(1)):60-68 doi:10.1002/gps.5215.

    PMID: 31642105
  2. 2

    Predictive testing for neurodegenerative diseases in the age of next-generation sequencing.

    Goldman J, Xie S, Green D, et al.

    Journal of genetic counseling 2020; doi:10.1002/jgc4.1342.

    PMID: 33090625
  3. 3

    Psychological Impact of Predictive Genetic Testing for Inherited Alzheimer Disease and Frontotemporal Dementia: The IT-DIAfN Protocol.

    Galluzzi S, Mega A, Di Fede G, et al.

    Alzheimer disease and associated disorders 2022; (36(2)):118-124 doi:10.1097/WAD.0000000000000494.

    PMID: 35293381
  4. 4

    A mixed-methods study of cultural beliefs about dementia and genetic testing among Mexicans and Mexican-Americans at-risk for autosomal dominant Alzheimer's disease.

    Withers M, Sayegh P, Rodriguez-Agudelo Y, et al.

    Journal of genetic counseling 2019; (28(5)):921-932 doi:10.1002/jgc4.1133.

    PMID: 31207006
  5. 5

    Receiving a Pathogenic Variant in a Population Breast Cancer Screening Trial: A Mixed Method Study.

    Riddle L, James JE, Naeim A, et al.

    Public health genomics 2024; (27(1)):177-196 doi:10.1159/000540680.

    PMID: 39307132
  6. 6

    Genetic Counseling and Testing for Alzheimer's Disease and Frontotemporal Lobar Degeneration: An Italian Consensus Protocol.

    Bocchetta M, Mega A, Bernardi L, et al.

    Journal of Alzheimer's disease : JAD 2016; (51(1)):277-91 doi:10.3233/JAD-150849.

    PMID: 26901402
  7. 7

    The Effect of Predictive Testing in Adult-Onset Neurodegenerative Diseases on Social and Personal Life.

    Cohn-Hokke PE, van Swieten JC, Pijnenburg YAL, et al.

    Journal of genetic counseling 2018; (27(4)):947-954 doi:10.1007/s10897-017-0195-3.

    PMID: 29270849
  8. 8

    A survey of attitudes toward clinical trials and genetic disclosure in autosomal dominant Alzheimer's disease.

    Grill JD, Bateman RJ, Buckles V, et al.

    Alzheimer's research & therapy 2015; (7(1)):50 doi:10.1186/s13195-015-0135-0.

    PMID: 26203303
  9. 9

    Protocol considerations for multigenerational blinding of preimplantation genetic testing for a monogenic condition for Huntington disease: a case report.

    Raine S, Siegel DR, Rabkina L, et al.

    F&S reports 2025; (6(2)):201-205 doi:10.1016/j.xfre.2025.03.007.

    PMID: 40620380
  10. 10

    A review of the flortaucipir literature for positron emission tomography imaging of tau neurofibrillary tangles.

    Burnham SC, Iaccarino L, Pontecorvo MJ, et al.

    Brain communications 2024; (6(1)):fcad305 doi:10.1093/braincomms/fcad305.

    PMID: 38187878
  11. 11

    Earlier Alzheimer's disease onset is associated with tau pathology in brain hub regions and facilitated tau spreading.

    Frontzkowski L, Ewers M, Brendel M, et al.

    Nature communications 2022; (13(1)):4899 doi:10.1038/s41467-022-32592-7.

    PMID: 35987901
  12. 12

    Autosomal Dominant Alzheimer Disease: A Unique Resource to Study CSF Biomarker Changes in Preclinical AD.

    Schindler SE, Fagan AM

    Frontiers in neurology 2015; (6()):142 doi:10.3389/fneur.2015.00142.

    PMID: 26175713
  13. 13

    Comparison of CSF biomarkers in Down syndrome and autosomal dominant Alzheimer's disease: a cross-sectional study.

    Fagan AM, Henson RL, Li Y, et al.

    The Lancet. Neurology 2021; (20(8)):615-626 doi:10.1016/S1474-4422(21)00139-3.

    PMID: 34302786
  14. 14

    Diagnostic accuracy of phosphorylated tau217 in detecting Alzheimer's disease pathology among cognitively impaired and unimpaired: A systematic review and meta-analysis.

    Khalafi M, Dartora WJ, McIntire LBJ, et al.

    Alzheimer's & dementia : the journal of the Alzheimer's Association 2025; (21(2)):e14458 doi:10.1002/alz.14458.

    PMID: 39711334
  15. 15

    Plasma p-tau217 in Alzheimer's disease: Lumipulse and ALZpath SIMOA head-to-head comparison.

    Pilotto A, Quaresima V, Trasciatti C, et al.

    Brain : a journal of neurology 2025; (148(2)):408-415 doi:10.1093/brain/awae368.

    PMID: 39679606
  16. 16

    Discriminative Accuracy of Plasma Phospho-tau217 for Alzheimer Disease vs Other Neurodegenerative Disorders.

    Palmqvist S, Janelidze S, Quiroz YT, et al.

    JAMA 2020; (324(8)):772-781 doi:10.1001/jama.2020.12134.

    PMID: 32722745
  17. 17

    A Case of Early-Onset Alzheimer's Disease Mimicking Schizophrenia in a Patient with Presenilin 1 Mutation (S170P).

    Kim HR, Jang JH, Ham H, et al.

    Journal of Alzheimer's disease : JAD 2021; (83(3)):1025-1031 doi:10.3233/JAD-210650.

    PMID: 34366354
  18. 18

    Epidemiology of early onset dementia and its clinical presentations in the province of Modena, Italy.

    Chiari A, Vinceti G, Adani G, et al.

    Alzheimer's & dementia : the journal of the Alzheimer's Association 2021; (17(1)):81-88 doi:10.1002/alz.12177.

    PMID: 32914938
  19. 19

    Evaluating pathogenicity of variants of unknown significance in APP, PSEN1, and PSEN2.

    Marsh JA, Huang G, Bowling K, et al.

    Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics 2025; (22(3)):e00527 doi:10.1016/j.neurot.2025.e00527.

    PMID: 39875235
  20. 20

    Positron emission tomography and magnetic resonance imaging methods and datasets within the Dominantly Inherited Alzheimer Network (DIAN).

    McKay NS, Gordon BA, Hornbeck RC, et al.

    Nature neuroscience 2023; (26(8)):1449-1460 doi:10.1038/s41593-023-01359-8.

    PMID: 37429916

This page explains diagnostic tools and genetic testing for Autosomal Dominant Alzheimer Disease for educational purposes. Always consult a certified genetic counselor or neurologist before pursuing predictive testing.

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