Genetic counselors: Your partners in clinical practice

WHO ARE GENETIC COUNSELORS?

Genetic counselors are allied health professionals with a master’s degree and with specific expertise in identifying and educating patients at risk for inherited conditions. They are certified through the American Board of Genetic Counseling. Genetic counseling is a licensed profession in many states,¹⁹ and licensure legislation is pending in several others.

HOW GENETIC COUNSELORS FACILITATE DIFFICULT COMPONENTS OF GENETIC TESTING

Genetic counselors can serve as complementary practitioners who possess the time and expertise to discuss some of the more complex components of the genetic testing process, further discussed here.

Making sure that testing is appropriate and that the right test is ordered

Let us revisit our introductory scenario—a patient presents to your office and relates a family history of colon cancer. What would you do if she then says, “I know there’s a gene for colon cancer; I want that test today so I can know if I’m at risk.” You get the sense that the patient is anxious and determined to get this testing done today. Which of the following would you do?

• Say “OK,” enter “colon cancer gene” in your hospital’s laboratory ordering system, and pray that the results are normal.
• Remember that a representative from a genetic testing company came by your office and left sample collection kits. Say “OK,” draw the patient’s blood in the tubes provided, check off testing for “comprehensive colorectal genetics panel,” and pray the results are normal.
• Tell the patient: “Most colon cancers are not necessarily caused by an inherited syndrome. However, a detailed analysis of your family history seems warranted. There are many genes that can play a role in inherited colon cancer risk, and I want to make sure the right test is done for the right person in your family. I’m going to refer you to a genetic counselor who can take a detailed family history and discuss the risks and benefits of genetic testing with you.” You make the referral and within 1 or 2 weeks, your patient is seen for genetic counseling.

If you chose ‘colon cancer gene’ testing

The phlebotomy and laboratory personnel at your facility are likely unsure what kind of sample to draw and where it should be sent. As of this writing, at least 14 genes have been associated with a risk of colorectal cancer, and testing for these genes is available through dozens of laboratories across the country.

In this scenario, your hospital does not have sufficient information to follow through on your orders, and someone pages you to discuss it. However, you are in the midst of a busy clinic and are not able to return the page promptly, so the laboratory informs the patient that it cannot draw her blood for testing today. The patient leaves feeling angry and upset.

If you chose commercial genetic testing

You may have just ordered testing for four of the genes known to cause Lynch syndrome, an inherited condition predisposing to colon, uterine, and a few other cancer types. While testing like this may be labeled as “comprehensive,” it may not include all disorders associated with colon cancer. Such shotgun approaches to patient care without consideration of family history can often lead to ordering genetic testing that may be not only medically unnecessary, but also not reimbursable by insurance companies.

Continuing with the case above, the patient’s insurance company determines that testing is not medically necessary, and she is billed for the entire cost of more than $4,400. Her results are normal, and she feels reassured that she is not at increased risk of colon cancer.

A year later, the patient phones you to say that her uncle had genetic testing with positive results. She sends you the letter she received along with the genetic counselor’s clinic note—the uncle’s mutation is in a completely different gene from the ones you tested. While she was previously told she was at low risk, the appropriate site-specific genetic test (average cost range $185–$450) to target the specific mutation is positive, and she is at increased risk of colon cancer, but is now able to pursue increased screening to reduce her risks of developing and dying from this disease.

If the patient had not been made aware of her uncle’s results, she may not have received this screening. If she were diagnosed with later-stage colon cancer after developing symptoms, she may feel you are liable for this diagnosis based on her perception that she was not at risk according to the previously negative genetic testing results ordered by you. After learning about her family history and that the right test was not ordered for her, the patient pursues legal action.

If you chose genetic counseling

If you chose to refer the patient for genetic counseling, congratulations! Your patient is seen for risk assessment and genetic counseling.

As part of the genetic counseling session, a comprehensive family history identifies the patient’s uncle who was diagnosed with colon cancer. He was previously seen for genetics assessment and was found to have a mutation in the APC gene, predisposing him to familial adenomatous polyposis. Site-specific testing, which the genetic counselor is able to get covered by the patient’s insurance through a letter of medical necessity, reveals that your patient shares her uncle’s mutation. As indicated by national guidelines, you refer the patient to a gastroenterologist for medical management, which will significantly reduce her chances of developing and dying of colorectal cancer.

It is preferable to see the family member at highest risk for an inherited condition—usually, but not always the affected relative—for genetic consultation first. During the consultation the genetic counselor would decide which syndrome, if any, is the best fit for the family.

If the affected relative tests positive, targeted and less costly testing for the specific mutation identified (ie, site-specific testing) can then be offered to family members to provide a yes-or-no answer as to their risk status.

If the relative most likely to be gene-positive tests negative, no genetic testing would be recommended for family members, as the genetic cause of the cancer in the family is unknown. In this situation, family members may be advised to pursue the same screening measures as those with a positive gene test due to their strong family history.

INFORMED CONSENT FOR GENETIC TESTING

Genetic testing consists of much more than a simple blood draw. Obtaining informed consent for genetic testing is a crucial step in the testing process, as the results can be complex and often affect multiple family members. When predictive genetic testing is being discussed, special conversations need to take place to make sure that decisions are well informed. Genetic counselors can facilitate these discussions and guide patients and families through the decision-making process.

Example: Huntington disease

The need for genetic counseling before predictive testing is best illustrated by Huntington disease, a progressive neurodegenerative disorder with typical onset in the third or fourth decade of life. Over the disease course, patients experience decreases in motor control (leading to the aptly named “Huntington chorea”), cognitive decline, and changes in psychiatric state. Ultimately, most patients die 15 to 20 years after the onset of symptoms. Treatment is palliative and symptom-based.

Huntington disease is inherited in an autosomal dominant manner, meaning that each child of an affected person has a 50% risk of inheriting the gene change responsible for this condition and of eventually developing the disease. It is caused by an expansion within the HD gene; this expansion may grow with successive generations, leading to earlier onset of symptoms.²⁰

The availability of predictive testing—which enables people who are at risk but who are without symptoms to find out their genetic status—ultimately leads each at-risk person to ask herself or himself, Do I want to know? Studies have found that only 15% to 67% of offspring of parents with Huntington disease (offspring are at 50% risk of the disease) elected to be tested, and in one longitudinal study, this rate of “uptake” decreased over time.^21,22 However, any estimates of uptake may be falsely elevated, given the likelihood that those not wishing to consider testing may not feel the need for a clinical visit focused on this subject.

After predictive testing became available, an increased risk of suicide in persons at risk of Huntington disease was documented.^23,24 In view of this risk and the careful decision-making support that people at risk need, predictive testing guidelines were developed by a committee of medical experts and members of Huntington disease family organizations.²⁵ As part of the guidelines, a multivisit pretesting process was established that includes extensive education and counseling. Delay of testing is recommended when contraindications are identified, such as evidence of coercion or a serious psychiatric condition. Most genetic testing companies offering predictive testing require a signature from the ordering clinician verifying that pretest counseling has been completed; some also include a provision that the ordering clinician will relay results to the patient in person.

More than 15 years after these guidelines were adopted, a study of suicide risk in at-risk persons continued to find rates higher than in the general population, but lower than in earlier studies.²⁶ Whether this careful pretest counseling protocol is directly related to a possible decrease in suicide risk has yet to be established, but its successful use in patients undergoing predictive Huntington disease testing has led to its adoption in other neurodegenerative diseases such as Alzheimer disease and Parkinson disease.