Posted 4 June 2007

Important Notice: Alzheimer Research Forum does not provide medical advice nor promote any product or service. The contents are for informational purposes only and are not intended to substitute for professional medical advice, diagnosis or treatment. Always seek advice from a qualified physician or health care professional about any medical concern, and do not disregard professional medical advice because of anything you may read on this web site. The views of individuals quoted on this site are not necessarily those of the Alzheimer Research Forum.

Protocol for Predictive Testing

Introduction by Gabrielle Strobel

This is a simplified version of the protocol for predictive testing as used at the Alzheimer Disease Research Center at Columbia University, New York. It is based on the protocol for Huntington disease developed at the Columbia University Medical Center Huntington's Disease Center of Excellence. Huntington's has a longer history of genetic testing than does AD. It poses similar challenges to AD and therefore serves as a guiding example for predictive testing in AD. This is a generic sample of the type of interdisciplinary, careful process that is generally recommended for predictive testing of Alzheimer's and related dementias. Individual centers modify it depending on the resources available locally. Your center will not follow this protocol verbatim. The purpose of this page is to give you an idea of what kind of interactions to look for if you are considering predictive testing and wish to do so in a way that is supported with professional safeguards.

Minimally, predictive testing should include the following:

Pre-test genetic counseling.
Neurological consultation.
Additional counseling as needed with a psychiatrist, social worker, or family therapist.
Disclosure and post-testing counseling.
A support person to accompany the at-risk individual to all appointments.

PREDICTIVE TESTING

The process usually begins with a telephone conversation with the genetic counselor. It serves to assess if the interested individual is a candidate for predictive testing, to explain the procedure, and to discuss the cost of the genetic testing program and options of handling it. If the individual wishes to pursue the program, the counselor schedules an office visit.

Pre-test Genetic Counseling
This appointment is usually with a genetic counselor and/or geneticist. At this session the following issues may be explored:

Implications of testing for person at-risk.
      a. What was his/her experience of the disease in the family?
      b. Why does he/she want to know?
      c. What would he/she do differently?
      d. How will the results affect relationships with spouse, children,
      family? Work? How does spouse/family/significant other feel about it?
      e. Timing of testing. (What are the individual's needs?)

Risks of genetic testing:
      1. Social/Economic Risks
           a. Health/life/long-term care insurance.
           b. Employment issues.
           c. Family/social relationships.
      2. Psychological/emotional risks.
           a. Possible loss of hope for the future (with positive result).
           b. Depression (with positive or negative result).
           c. Survivor guilt if siblings test positive (with negative result).

Benefits of genetic testing:
      1. Positive test result
           a. End uncertainty of whether one has inherited the gene.
           b. Planning for the future—career, education, family, financial.
      2. Negative test result
           a. End uncertainty of whether one has inherited the gene.
           b. Relieve anxiety of worrying whether a person will develop AD.
           c. Information for children.

An evaluation of support systems.
A discussion of the genetics of Alzheimer disease including risk assessment; limitations of testing; alternatives to testing (not to take the test, DNA banking for future use by family members and/or for research).
Review of the laboratory consent form.

Neurological Examination
The purpose of this examination is to assess the presence or absence of any neurological signs of the disease. This evaluation may include extensive neuropsychological testing, brain imaging studies, and additional blood tests.

At some centers, the neurologist, genetic counselor, and, where available, psychiatrist and/or social worker meet to discuss the data available to date. The genetic counselor and the client then may meet a second time to review, discuss whether the client wants to continue, and if so, prepare for disclosure, discuss possible impact of test result, and draw blood for test.

Disclosure Visit
Genetic counselor, social worker, neurologist/psychiatrist.

Results are given in person to the individual and support person. Results will not be given by mail or over the phone.
Summary note sent explaining results, reviewing follow-up plan and available resources.
The genetic counselor and/or social worker will be available to contact for follow-up after results.
Referral to support services including the Alzheimer's Association or therapist.

Follow-up
Genetic counselor and/or social worker.

Future follow-up as needed or requested.

Note: The HD protocol on which this sample AD predictive testing protocol was based derives—as do similar protocols at other centers nationally and internationally—from guidelines established by the International Huntington Association and the World Federation of Neurology Research Group on Huntington's Chorea. The original publication is Guidelines for the molecular genetics predictive test in Huntington's disease. J Med Genet. 1994 Jul;31(7):555-9. See Abstract.