Q+A: Genetic Testing and Medical Treatment

Aug. 22, 2007 — -- Thank you for your interest in Bill Weir's piece on the use of DNA tests to detect what medical conditions you may develop later in life.

Colleen McBride of the National Human Genome Research Institute offers the following answers to your questions.

A number of people expressed interest in getting the genetic susceptibility test shown in the news report. The test shown is only for research and is not available. In fact the test is still considered experimental because it has not been shown yet to have health benefits.

The woman who received her test results on air is participating in a research study to evaluate the test. The study has very specific criteria for who can take part, and we cannot accept volunteers.

However, if you are interested in being involved in genetic research studies, many universities and research institutions are looking for participants and would appreciate your help. You can also contact the National Society of Genetic Counselors for services in your region (www.nsgc.org/resourcelink.cfm).

It is possible to obtain similar types of genetic tests for common diseases directly through the Internet (which are generally priced between $100 and $1,000). It is important to know that there are few federal regulations controlling these tests, which means that the companies may make exaggerated claims about what the tests can do. Additionally, the tests may not be accurate.

A number of government committees and medical societies have investigated these genetic testing companies. Their reports have expressed a number of serious concerns about the validity of this type of genetic testing and discourage the purchase of genetic tests without the recommendation of a doctor.

Almost nothing is known about whether these types of tests have any health benefits. While genetic testing for common diseases may be useful in the future, the genetic evidence for these tests does not yet support their use except in research studies.

Here are more answers to some of your specific questions:

QUESTION: My daughter, age 31 has MS. Her husband, age 33, just got diagnosed with AS. They have two sons, ages 1 and 4. Would their sons benefit from DNA testing? Thank you for your reply -- Carmel Valdez, Colton, CA

ANSWER: The most appropriate way to address any concerns about the possibility for inherited disease would be to contact a clinical genetics team within their area. A genetics team can do a comprehensive review of medical and family histories. It is this type of detailed information that is needed to assess whether genetic testing would be beneficial to a family or not. A genetics team can help in assessing risks and discussing whether genetic testing is possible, while considering the pros and cons of such testing. -- Colleen McBride

QUESTION: If people get the testing, wouldn't this be a way for health or life insurers to decline covering a person based on a condition they might get in the future? Rose, Pennsylvania

ANSWER: This is a reasonable concern. Currently, there is national legislation in the works to make genetic discrimination illegal.

However, at this point it remains a possibility that has greatly hampered genetic research and advancement. In the context of this study, the test results are not entered into the participant's medical record and there are other protections in place to ensure confidentiality. -- -- Colleen McBride

QUESTION: I recently found out I was adopted. My birth father has passed away and my mom just passed away this past January. She had lung cancer. I would be very interested in finding out what diseases might affect me since I have an unknown medical background on my fathers side.

Couldn't this type of testing be done routinely for adopted individuals who do not know anything about their medical backgrounds?-- Shelly, Birmingham Ala.

ANSWER: In the future, genetic testing may be useful for those who do not have a complete family history of diseases, since it can give some information about the genetic components of disease risk. However, it will not be able to detect the complex environmental factors that also influence peoples' risk for disease. -- Colleen McBride

QUESTION: I was diagnosed with protein losing enteropathy approx. 9 years ago, with no disease present. Would this testing tell be why my auto-immune system stopped working, and what I can do to get it re-started? -- Penny, Sturgeon Bay, WI

ANSWER: No this test would not give you any information about your auto-immune system. These are questions best taken up with your doctor. -- Colleen McBride

QUESTION: Do you think HMO's like Kaiser Permente will be using this in the future to help patients prevent diseases, therefore cutting health care costs and increasing profits for them? -- Jason, Northglenn, Colorado

ANSWER: The honest answer here is that we don't know. We are conducting this research study to try to begin understanding whether this use of genetic testing is likely to have health benefits.

Whether it will actually be useful in practice remains and open question. The research that you heard about last night is intended to see if these tests are useful to patients. This is only the first step in learning whether genetic tests like this have any health benefits for patients.

The hope is that such testing will help patients prevent diseases and this type of research will tell us how to do that. In the ideal, patient consumers would benefit from savings in health care costs and be healthier as well. -- Colleen McBride

QUESTION: Exactly what genes and SNPs are being tested in the Ford Hospital Study?

ANSWER: If you are interested in the details of our study, including information about what genes and SNPs are included in the test, please visit our Web site at: https://multiplex.nih.gov/ -- Colleen McBride

QUESTION: Do the laboratories that offer these tests have any governmental/professional oversight? Do these companies have genetic counselors or other clinically trained geneticists to interpret/explain results to patients?

I am a genetic counselor and am very concerned about how these tests are being advertised and offered to the general public -there is tremendous risk for misinterpretation of these tests without the proper oversight andcounseling. -- Cheryl, Troy, Mi.

ANSWER: In the case of the study described in last night's broadcast, we are following government regulations for returning quality genetic test results to our participants.

With regard to tests offered over the Internet, there is some oversight of these tests but it is generally agreed that the current regulations are insufficient. As for genetic counseling, some of the Internet companies offer it, while others do not. In the case of the study described last night, a good deal of effort is being extended to make sure that participants understand the meaning of their test results. -- Colleen McBride

QUESTION: Cancer has taken close family members on both sides. Are there any tests I should get to screen myself?

ANSWER: There are a number of effective screening tests for colon cancer, breast cancer and cervical cancer. Indeed these tests have far more evidence to support their benefits for health than any of the genetic tests that are currently available. -- Colleen McBride

QUESTION: What do you think is the benefit of testing and revealing to individuals their currently incurable genetic dispositions? How are you prepared to address the physiological as well as psychological ramifications of these scientific facts? -- Michelle, New York, N.Y.

ANSWER: The test you learned about last night only includes health conditions for which individuals can take actions to prevent their occurrence.

Ultimately, where tests are available for other incurable health conditions, current thinking is that it should be up to the individual to decide whether this information has any personal benefit. Assisting individuals in deciding if such testing is appropriate should include genetic counseling and support. -- Colleen McBride

QUESTION: Can a blood test be used to detect cardiovascular disease? I don't mean HDL/LDL cholesterol as my husband Jim's numbers were pretty good even though he totally flunked a heart scan and had quadruple bypass surgery in his 50's. Jim's father died young of a heart attack. Can our 24-year-old son be blood tested to see if he inherited Jim's heart gene, or must he wait another ten years for a heart scan? Thanks. -- Cheryl, Boulder, CO.

ANSWER: There currently isn't a genetic test that can tell you exactly what your son's risk will be. The genetic test that use in the study described last night is experimental. Even though it includes genes which do influence risk for heart disease, each gene only has a small impact on risk.

At this point in time, a positive family history of a disease is a much better predictor of risk than genetic testing. But remember, heart disease can be prevented, and it is a good idea to discuss strategies for addressing your risk with a doctor. -- Colleen McBride

QUESTION: Is genetic testing available for schizophrenia? My stepdaughter has schizophrenia or schizoeffective disorder, and her two brothers do not. Can the brothers be genetically tested to determine if their offspring will have schizophrenia? Thanks -- Carla, Houston, Texas

ANSWER: The most appropriate way to address any concerns about the possibility for inherited disease would be to contact a Clinical Genetics Team within their area. A genetics team can do a comprehensive review of medical and family histories. It is this type of detailed information that is needed to assess whether genetic testing would be beneficial to a family or not. A genetics team can help in assessing risks and discussing whether genetic testing is possible, while considering the pros and cons of such testing.