The genomic era has given us an eye-popping 32,000 genetic tests for 5,800 medical conditions involving 3,900 genes, according to the Genetic Testing Registry, a database sponsored by the National Institutes of Health.
The number of tests has more than doubled in the last two years and continues to grow dramatically, driven by new technologies.
How then is a patient ̶ or even a physician ̶ supposed to understand this avalanche of new tests and make smart medical decisions about what the tests reveal?
“Genetic counselors can be an ideal resource to help you navigate the evolving genetic testing landscape and protect your health,” says Joy Larsen Haidle, a certified genetic counselor at the Humphrey Cancer Center in Robbinsdale, Minn., and president of the National Society of Genetic Counselors (NSGC). “An informed consumer is also an empowered consumer.”
The power of genetic testing and counseling took center stage in the national consciousness recently when the actress Angelina Jolie Pitt credited them with saving her life. Concerned about her familial risk of cancer – her mother, grandmother and an aunt all died of the disease – she received counseling and decided to take a blood test.
The results showed she had a mutation in her BRCA1 gene that gave her up to an 87 percent risk of getting breast cancer and up to a 50 percent risk of getting ovarian cancer. Those sobering numbers convinced Jolie Pitt to have her breasts surgically removed, almost certainly preventing breast cancer for the rest of her life.
As they were for Jolie Pitt, genetic counselors can be a critical part of a patient’s health-care team. They are medical professionals who hold specialized master’s degrees focused on genetics, health and related psycho-social issues. Their training is designed to guide patients through a potentially difficult time by discussing with them how their particular genetic makeup could impact them and their families, now and in the future.
“The skill sets held by genetic counselors are a unique combination of intense science, critical thinking and empathic counseling,” says Larsen Haidle. “It is unique to understand complicated scientific concepts and be able to explain them in a meaningful and supportive way.”
Genetic counselors are a rare breed. There are only about 3,000 certified counselors nationwide, but the profession is projected to grow by 41 percent through 2022, according to the U.S. Bureau of Labor Statistics.
The first genetic counselors graduated in 1971 from Sarah Lawrence College in Bronxville, N.Y. They worked mostly in obstetrics and pediatrics, counseling parents and interpreting genetic test results for conditions such as phenylketonuria (PKU), a metabolic defect inherited by newborns that causes mental retardation if not treated.
Today genetic counselors graduate from any one of about 30 training programs across the country. They cover just about any disease or condition that could affect you or a family member, working in medical specialties such as cardiology, hematology, infertility, metabolic disorders, neurogenetics, oncology, pediatrics, personalized medicine and psychiatric disorders.
Patients are often referred to genetic counselors after a physician assesses their family medical history or after a diagnostic test raises a red flag about a particular condition or disease. Patients can also engage counselors on their own. (The NSGC sponsors a free directory of counselors at www.findageneticcounselor.com.)
Before engaging a genetic counselor, it’s helpful to know some practical information:
(The Jackson Laboratory sponsors a Clinical and Continuing Education Program to help doctors and other health-care providers better integrate genomic-based medicine and genetic risk assessment into their practices. The program offers workshops and online courses for Continuing Medical Education credit.)
When you visit a genetic counselor, expect to be asked a lot of questions. Counselors are trained to follow the adage, “Seek first to understand, then to be understood.”
“One essential piece of the entire genetic counseling process is sitting down with the patients and discussing, ‘What brings you in today,’” says Robin Schwartz, a certified genetic counselor and assistant professor of genetics and genome sciences at UConn Health in Farmington, Conn.
Counselors will then collect the patient’s personal medical history, lifestyle habits and family medical history – still the “Holy Grail” of disease risk assessment after a half century.
“Family history is the core of precision medicine,” says Larsen Haidle. “It can be used to determine the chances of developing certain health problems, determine if surveillance should begin earlier than the general population or be done more frequently, and determine if genetic testing would be beneficial.”
Then follows a discussion of health risks that can be assessed, which genetic tests are most appropriate, which disease-prevention or management strategies might flow from the tests, and any emotional, financial and life-planning issues that might impact patients and their families.
“Genetic counselors are great partners in working with providers and patients to help select the best test and to discuss its benefits and limitations so the patient can make an informed decision,” says Kate Reed, a certified genetic counselor who directs JAX’s Clinical and Continuing Education Program for health-care providers. “This type of collaboration is necessary to ensure the right treatment to the right patient at the right time with everyone engaged in the decision making.”
For decades the medical community relied heavily on single-gene tests to assess disease risks. But with ever-faster and cheaper DNA-sequencing technologies, more extensive assays are joining the testing arsenal.
Multi-gene panels can assess several genes simultaneously for mutations, or variants, linked to disease. Whole-genome tests can survey the body’s entire genetic code – all 3 billion letters of it – for variants. And whole-exome tests can detect variants in all of the body’s protein-encoding genes, comprising about 1 percent of the genome.
These more expansive genomic tests bring more power but also more complexity. Paradoxically, the more genetic information they yield, the less certainty and control the information typically brings.
“Interpreting results can be challenging, as many of the genes have not been studied on a broad population,” Larsen Haidle says. “The results must be interpreted in the context of the available data.”
Genetic counseling sessions are therefore more likely to focus on probabilities than on absolute certainties, especially when “variants of unknown significance” or “incidental findings” emerge from tests.
Variants of unknown significance are genetic mutations that may or may not increase risk of disease. They simply haven’t yet been studied sufficiently for their impact to be judged.
Incidental findings are variants unrelated to the disease or condition being assessed. They can be linked to the risk of another disease or be benign and inconsequential to health.
Counselors can walk patients through an informed-consent process to determine whether they want to know such information and what it might portend for them or their families.
“Genetic counselors have always dealt with these uncertainties,” says Larsen Haidle. “Any time a new test comes to the market there is a learning curve while additional data is generated and the understanding of the breadth of impacts a gene alteration can have on health. Genetic counselors are adept at reviewing the literature and scrutinizing the data in the context of their patient’s personal or family history.”
Genetic counselors keep pace with rapid technological change through continuing education, a requirement for maintaining their certification by the American Board of Genetic Counseling.
“I’ve seen so many changes,” says Schwartz, the UConn Health counselor who has practiced for 40 years. “Having the ability to counsel people based on specialized genetic test results has always been changing, and technology continues to emerge.”
Schwartz, an adviser to JAX’s Clinical and Continuing Education Program, says incorporating genomic-based, precision medicine will be the profession’s next big challenge and opportunity.
“I think there’s tremendous promise,” she says. “We’re finding out things that are unique to an individual that helps doctors find better and more precise treatments. That’s an area that’s going to be expanding. We’re just now learning how to identify that uniqueness in individuals.”