GENETIC COUNSELING AND TESTING FOR CDH1 GENE MUTATION

Genetic counseling is an essential component of the diagnosis of Hereditary Diffuse Gastric Cancer syndrome (HDGC), one that should not be overlooked.

Getting tested

Talk to your primary care provider about your family health history, and update him/her at every well visit. If you think that your family might have HDGC syndrome, request a referral to a genetic counselor to discuss this and consider genetic testing.

A genetic test should not be performed without some form of genetic counseling. It is important to fully understand genetic testing, to be prepared for what you may learn, and to avoid unintended consequences. Take time to consider your situation, and seek the services of a genetic counselor. If there is not a genetic counselor in your area, often times telephone appointments can be arranged.

Seek out a genetic counselor

Ask for a referral to, or appointment with a genetic counselor experienced in cancer genetics. Find a genetic counselor near you. The genetic counselor should be your top resource to prepare and process the testing experience.

Prepare information on your family history of cancer before meeting with the counselor. Information such as the types of cancer and the ages of diagnosis of the cancers in your family will be most helpful to collect before your appointment. Finally, if a family member has already pursued genetic testing, it is important to bring a copy of their test report. Learn how to prepare for a genetic counseling appointment.

Consider bringing a friend or family member (or both!) to your genetic counseling appointment. The genetic counselor will review a lot of information during the visit and it is often helpful to have someone accompany you. Close friends and family may also serve as support, since the experience can be stressful and emotional for some people.

Proceed with genetic testing through a genetic counselor

Not all tests are created equal. Your genetic counselor will work with a CLIA-approved laboratory that will provide you with the most up to date and complete testing. A CLIA-approved laboratory meets federal regulatory standards for tests performed on humans. Genetic counselors also work with laboratories that have expertise in interpreting results in cancer predisposition genes like CDH1. Working with these types of laboratories reduce the likelihood of results such as false negative or false positives.

What this means: If you use a lab that gives you a false positive you may undergo unnecessary surgery such as a gastrectomy only to later discover you did not need the procedure. Alternatively, a false negative may be falsely reassuring and the error is only realized when you are later diagnosed with preventable stomach or breast cancer.

If you are interested in proceeding with a lab that offers direct to consumer testing, read What are the benefits and risks of direct-to-consumer genetic testing? to learn more about some of the risks associated with using these types of labs. Note that the HDGC Guideline (2020) states that results from direct-to-consumer test results be validated.

Tell your genetic counselor how you to choose to receive your test results, either by phone or in person. Your results should always be given to you through speaking with your genetic counselor, not by an automated service or mail. The genetic counselor will help you process the results, give you resources to contact regarding your next steps, and answer any questions you have.

It is difficult to predict how you will feel once you obtain your genetic test results. Some patients prefer to work with a mental health professional (psychologist, therapist, etc.) while others seek out the support of others who have been tested themselves. Talk to your genetic counselor if you feel you would benefit from additional support.

I am worried about a positive genetic test result being used against me as a preexisting condition

When you meet with a genetic counselor ask them to review information about the Genetic Information Nondiscrimination Act (GINA). This is a national law in the US, which prohibits most employers and group health insurers from using your genetic status as a pre-existing condition. However life insurance, disability insurance, and long term care insurance are exempt from this non-discrimination requirement. Military personnel are also not protected by this law. This easy to read resource will help you better understand the GINA law.

If you test positive for a pathogenic variant in the CDH1 gene (or any gene variant), and you work for a large company, your employer’s group health insurer should not be able to use this information against you. The military and life & disability insurers are legally permitted to refuse service or coverage based on your genetic status. Therefore, if you ever plan to have a life or disability insurance policy, it may be helpful to establish these policies before you proceed with genetic testing.