DNA Testing for Heritable Diseases

Question

Does anybody know the difference between genetic testing for heritable diseases and genetic testing for genealogy and history? I turned down genetic testing at a major NCI designated comprehensive cancer care center after a breast cancer diagnosis due to being unable to confirm Ashkenazi Jewish roots. (Not to worry, I am completely cancer free. I fought the system and waited six months for my second surgery after a breast cancer diagnosis. After the second surgery, the pathology report found that my cancer had vanished. Warning: Do not try this approach without extensive consultation with your breast cancer treatment team!)

After I stumbled on what appear to be vetted official records identifying numerous family members as being Jewish, I wrote the doctors that treated my breast cancer. I got a letter today with an appointment for follow up with the genetic testing group at the cancer care treatment facility.

I gather that the testing will not identify ancestors. Is this type of genetic testing conducted solely to discover genetic mutations that show an elevated risk for certain heritable diseases? I believe that NCI may be trying to construct family trees, as they asked me to provide information about any cancer in my family and to provide names and dates for family members (alive or deceased) with cancer but I had no reliable data to report.

Wow, this has been a journey. I started out to work on my family tree and my family history has unfolded in a most mysterious way. Some family lines that could be affected are listed below.

Answer 1

Both types of tests look at the same DNA, but NCI's testing won't give you the information you need for genealogical purposes, and the testing services that market to consumers aren't allowed to give you the kind of health-related information that NCI will provide. So if you want DNA data for genealogical purposes, you will also need to test with a consumer-oriented service.

I think 23andMe is the only testing service for consumers that includes a significant amount of health-related information, in addition to data that can be used to understand ancestry. I tested at 23andMe before the U.S. Food and Drug Administration (FDA) told them to stop giving health-related information to their customers. For customers who opted in (customers had to opt in to get potentially bad news about genes related to breast cancer, Alzheimer's, and possibly also Parkinson's disease), 23andMe gave data on the major BRCA1 and BRCA2 mutations and some other genes with some relationship to breast cancer, but warned that their tests did not look for some other mutations that affect the genetic component of breast cancer risk. (Now that 23andMe has FDA approval to report some health-related information, I don't think BRCA mutations are on the list of what they are allowed to report.) I expect that NCI testing looks for all of those other known or suspected breast-cancer-related mutations. So you are getting some tests that you can't get from a consumer service, but you'll need to test with a consumer service to get genealogically useful DNA info.

Answer 2

23andMe is the most popular test which includes health related information.

Answer 3

Here are some example DNA test results from a company called MyRaid. This is a blood test for specific genes related to cancer, as shown in the report. Some of these genes are also in the 23andMe test.

I think there is much more to be discovered. Doctors want to know as much as possible about your family history of cancer and your genealogy. Maybe they will soon discover more gene mutations that are related to cancer.

Answer 4

I can't be sure without knowing the specifics of the NCI research program, but it's likely that they will be doing complete sequencing of some number of genes that have been implicated in cancers of various types (or possible whole exome or whole genome sequencing). They may discover a novel mutation that arose in the recent past within your lineage. Companies like 23andMe can only test for a limited number of known mutations that are somewhat common.

Comments

The recent past could be 1000 to 3000 years! There is a huge controversy over Semitic vs European origins of the Ashkenazi. What is fact is the large number of genetic mutations linked to heritable diseases.

What surprised me was the rapid response from my cancer doctors after I told them I found documentation of Jewish ancestry in the US. 80 percent of all Ashkenazi Jews live in the United States. I did not want to proclaim Jewish blood only on suspicion without some evidence.

I do know that these tests uncover risk factors for a large number of diseases. If I were of child bearing age, I might not want to know everything. However,my cousin on the maternal side has daughters with children, and she wants to know all there is to know