For Catherine Fine, a certified genetic counselor, it’s not unusual to meet people whose family trees are rife with cancer. Her patient “Ann,” whose tree was filled with healthy family members, did not have a standout case. Ann had uterine cancer and her uncle had colon cancer, but both had been diagnosed later in life.
“Statistically speaking, I didn’t think she’d be positive for any genetic markers for increased cancer risk,” Fine says. Fine is head of clinical cancer services at Genome Medical, a national medical practice that provides individualized genetic counseling to patients and healthy individuals around the country via phone and videoconference.
Though Ann’s personal and family history of cancer was not substantial, uterine and colon cancers are both associated with Lynch syndrome, a genetic condition in which a mutation in any one of five genes increases lifetime risk for these and several other cancers. After Fine counseled Ann on the risks and benefits of genetic testing for Lynch syndrome, Ann decided to move forward with it.
“It turned out that she did have Lynch syndrome, and it could have easily been missed,” says Fine, “because in this large family, there were lots of men and women living to older ages, and most were not getting cancer.”
Like many people, Ann didn’t know what a genetic counselor was before her first meeting with one. But genetic counseling is more prevalent now, as researchers learn about the relationship between genetics and human health and how to harness that relationship to prevent or cure illness. Genetic counselors guide people affected by and curious about these discoveries through this developing field.
Personal genetic navigators
Certified genetic counselors (CGCs), who hold master’s degrees and are certified by the American Board of Genetic Counseling, help uncover unseen risks for numerous health conditions. They put those risks into perspective for patients and their families, empowering them to make proactive choices.
Genetic counselors use their expertise to help patients, their healthcare providers, and their families to understand the implications of their family history. For example, says Fine, “many people are surprised to know that most cancer is not due to hereditary predisposition.”
“We see individuals as patients, but really their entire family is our patient.”
They also educate patients and healthcare providers on the possible benefits and limitations of tests. They ensure their patients understand the pros and cons of learning about their personal genetics. While results can help improve health, the information can cause fear and anxiety, too. For this reason, before recommending testing, counselors ensure that patients are prepared psychologically for the results. After genetic testing, counselors interpret the results, equip the patient with the right information to act on those results, and refer the patient to the appropriate specialists. Counselors also point out how the newly acquired genetic information could apply to other family members as well.
“We see individuals as patients, but really their entire family is our patient,” says Fine.
Genetic counselors aren’t physicians. They don’t treat or manage genetic conditions, though they often work alongside physicians to recommend appropriate tests and help them interpret results. “We are the navigators,” says Fine. “We’re not here to tell individuals what to do, but just to provide all the information: whether testing would benefit them, how some people might use the results, and how to interpret results. Basically, we give them the power to make the decisions.”
Cancer Red Flags: When to Seek Genetic Consultation
While we all can learn something from our personal genetics, if you are concerned about cancer risk, you are most likely to benefit from genetic counseling if you fall into any of the following categories:
• Have early onset of a disease that typically develops later in life, such as breast or colon cancer before age 50
• Have had more than one cancer diagnosis
• Have three or more relatives on the same side of the family with the same type of cancer
• Have triple negative breast cancer (breast cancer that tests negative for estrogen receptors, progesterone receptors, and HER2)
• Have ovarian cancer
• Have male breast cancer
• Have aggressive prostate cancer
• Have a family member with a known gene mutation that increases one’s risk of cancer
• Have certain combinations of cancer occurring on the same side of a family
When genetic testing and genetic counseling are recommended based on your medical history, many insurance companies will cover the costs. However, patients also have the option to pay out-of-pocket for these services if they are not covered.
Genetics throughout your life
Anyone can seek the help of a genetic counselor, whether they are trying to improve their understanding and treatment of a disease they have, prevent a disease they or their children could develop, or simply gather all the personal genetic information available to help maintain optimum health.
“I’m very healthy now,” says Judy, 70, who recently had her first consultation with a genetic counselor at Genome Medical. “I would like to stay healthy for as long as I can, so I want to know if anything in my genes gives any indication of changes I should make in my lifestyle to be healthier.” Through counseling, Judy and her daughter, who is 29, decided to have a genetic health screen for cancer and cardiovascular risk. Judy is open to whatever the test reveals.
“Everybody approaches the possibility of disease differently. Some people avoid going to the doctor because they don’t want bad news,” she says. “But I don’t fall into that category. I want to know what it is right away. I don’t think it will bother me to find out any of my results. But each person has to think about it carefully.”
Genetic counselors address health and medical concerns that arise over the entire lifespan. They consult with couples who are starting a family on their risk of conceiving a child with an inherited genetic condition. Based on the counsel they receive, couples might choose to test their carrier status for a handful of conditions most common among people of their ethnicity, or they could choose to screen for a panel of several hundred conditions. If testing determines that both prospective parents are carriers of, for example, the same autosomal recessive disorder, there is a 25 percent chance that the fetus will be affected. Counselors educate the couple about the condition and the odds that a child will be born with it.
“It’s typically an OB/GYN who orders this type of genetic testing, but they’re not always comfortable with counseling the patient about those results,” says Erynn Gordon, CGC, vice president of clinical operations at Genome Medical.
Gordon recalls a couple who learned that the prospective father was a carrier for a rare genetic condition called congenital disorder of glycosylation type 1a, which is associated with impaired vision, short stature, and muscle weakness. Because his wife’s carrier screen was negative, they had a low chance of having a child with the condition, but the would-be father still needed reassurance.
“He was a late bloomer, he told me. He was short, wore glasses, and wasn’t good at sports. He was concerned that those were symptoms of carrier status that he could pass on to his children. Genetic counselors help dispel those myths and misperceptions,” Gordon says.
When appropriate, counselors inform prospective parents who are both carriers about reproductive options such as IVF with preimplantation genetic diagnosis, intended to significantly reduce the risk of conceiving a child with a genetic disorder. They then refer them to the right specialist.
Couples with small children could seek genetic counseling to help determine whether a child’s developmental delay warrants testing for a genetic condition. Adults who see aging parents develop illnesses, such as heart disease or diabetes, may ask a genetic counselor to assess their own risk of developing those conditions and identify proactive steps to prevent them. People living with certain illnesses could use counseling to learn whether genetic testing would uncover the cause of the condition or point to effective treatments. Gene mutations not only impact risk for certain conditions; they can also alter the way the body responds to medications for those conditions. Known gene mutations can cause people to have severe adverse reactions to some drugs or to have no response to a drug at all.
Genetic conditions that require ongoing medical management, such as pediatric genetic disorders, are often referred to a medical geneticist. An OB/GYN who suspects genetic abnormalities in a fetus after a routine ultrasound, for example, might call in a medical geneticist. Also known as physician geneticists or clinical geneticists, these are doctors who have a specialty in medical genetics and are qualified to evaluate, diagnose, manage, and treat patients with hereditary genetic conditions.
“Medical geneticists and genetic counselors overlap somewhat in their roles of assessment and education around inherited disease,” says Gordon. “Genetic counselors add to that a focus on coordination of care, delivery of information, and emotional support, while their physician counterparts focus on diagnosis and medical management.”
Not a crystal ball
Genetic counselors can assess risks about an individual’s health based on family history and test results, but they aren’t fortune-tellers. Not all genes that play a role in the development of disease guarantee a person will one day have that disease, such as the BRCA1 and BRCA2 mutations, which increase lifetime breast cancer risk to three to seven times above average but don’t cause cancer.
“Even in families that seem to be riddled with cancer, we know that not everyone gets it,” Gordon says. “While we can provide guidance about cancer risk for those who carry a mutation in a hereditary cancer gene, we can’t actually predict who will go on to develop cancer.”
Genes may interact with other factors that lead to disease. The more factors involved, the less effective genetic testing may be at measuring risk. Genetic testing, for example, can’t predict a person’s risk for depression. “The scientific community doesn’t have a great understanding of how those risks work together in depression. It’s a complicated interplay of factors,” says Gordon.
Above all, genetic counselors won’t tell individuals what they should do, but they will arm them with the information needed to take control of their health. That’s what Ann did.
Before she met Fine, Ann had not heard of Lynch syndrome. “After she learned about her options, she recruited other family members who were at risk of having inherited Lynch syndrome and accompanied each one of them individually to their genetic counseling visits,” Fine says. “She was the family champion.”
Genetic tests explained
A genetic test is not a single test. Genetic testing can read a single gene or analyze the sum total of your genetic material.
Whole genome sequencing spells out all three billion letters — in combinations of A,T,G, and C — of a person’s genetic code. Information seekers who want to know as much as possible about their genes might be drawn to this, but researchers don’t yet know the significance of most of the human genome. The first human genome cost $2.7 billion to sequence. Today, it’s available for about $1,000.
Whole exome sequencing spells out all the letters in an individual’s exons — the parts of genes that contain the instructions for creating proteins — that make up about one percent of the genome. Most known disease-causing mutations occur in exons. Sequencing the entire exome could uncover many disease-causing mutations but could miss others. Exome sequencing starts at about $500.
Targeted gene panels analyze genes only for specific mutations related to a single condition or group of conditions, such as mutations that promote tumor growth. These tests do not provide any other genetic information. Doctors or genetic counselors typically order these tests for patients.
Single-gene tests analyze one gene for a specific disease of interest.
genotyping tests, such as 23andMe and AncestryDNA, search selected segments of DNA for markers known to indicate a high statistical likelihood that an individual comes from a certain ethnic background. Some DTC tests report on markers of increased risk for health conditions and carrier status of conditions that could be passed to offspring. While tests like these might point to a need to further explore a health issue with a healthcare provider, they cannot diagnose medical conditions. They cost up to $200, depending on the mix of ancestry
and health information included.