How to Assemble a Family Health History That Can Save Your Life
By: David H. Freedman
Tags: Genetics, Body, Science, Family, Health

How to Assemble a Family Health History That Can Save Your Life

It can be a powerful medical tool — especially now

Photo: teekid/Getty Images

According to the Centers for Disease Control and Prevention, “people of any age who have serious underlying medical conditions might be at higher risk for severe illness from Covid-19.” That’s an important fact, because it provides someone with an underlying condition an opportunity to take extra precautions to avoid exposure to the virus and, if infected, to alert physicians to the elevated danger.

Of course, that assumes you know if you have an underlying condition, which is not a given — one in 13 Americans have a health condition that has never been diagnosed, according to the Mayo Clinic.

One of the best ways to reduce unwelcome health surprises in this time of Covid-19, and all other times, is to arm your physician with a comprehensive family health history.

Everyone’s primary care physician asks patients early on about their family health history. “It’s pretty much essential for every patient who walks through the door,” says Aleks Rajkovic, MD, PhD, chief genetics officer at the University of California San Francisco (UCSF) Medical Center.

But Rajkovic adds that a patient’s family history will only be as useful as the level of detail of the information in it. “We often find that when we go over the family history in patients’ records, significant elements have been omitted,” he says. One study found that less than four percent of medical records contained a complete enough family history to assess the patient’s risk of cancer, heart disease, and other major diseases.

Filling in what’s missing from your family health history could prove critical to heading off problems — and in some cases could even give doctors a much better chance of saving your life.

Here’s what experts say you need to do to put together a good history.

“When a patient says to me they feel weird about picking up the phone to ask a relative what kind of cancer someone had, I tell them they have to get over it — this is their life.”

Go beyond your parents — up to a point

Parents are usually the single most important relatives in a family history, because you share half your genes with each of them, and your genes play a role in about 40% of all diseases.

But grandparents, siblings, aunts, and uncles can also play a huge role, because you share 25% of your genes with each of them (50% in the case of siblings). Their health histories can help establish a pattern in your genetics that may not be entirely clear from parents alone or may suggest that something is going on in your family that happened to skip your parents altogether.

For example, knowing only that one parent had kidney disease without knowledge of other relatives won’t tell a doctor much about your chances of inheriting a predisposition for the disease. But knowing that one of your grandparents, two aunts, and a sibling have all had it establishes a clear pattern of genetic predisposition, even if neither of your parents had it.

Information on first cousins isn’t normally going to be nearly as helpful. “You only share about 12% genetically with them, so it may not add a lot to the picture,” says Lisa Cannon-Albright, PhD, a professor of internal medicine and a genetics researcher at the University of Utah.

But get the information anyway, Cannon-Albright says, because for certain rare genetic conditions, that can be enough extra data to make a difference. Going out to second cousins and beyond, on the other hand, would be overkill.

Find out about all significant diseases and treatments

About 10% of all cancers are hereditary, meaning your genes play a large role in the risk of getting them. For example, American women on average have about a 12% chance of developing breast cancer in their lifetimes, but for a woman who has inherited the BRCA1 or BRCA2 gene, the chances can jump to as high as 70%.

About one in five people have genes that significantly raise their rate of heart disease, according to one study. In seeing a pattern of one of these diseases in a family history, doctors can often use that information to prescribe effective preventive care, such as more frequent screening for certain cancers or more thorough testing for potential heart problems.

But other, often less serious-sounding problems suffered by relatives should also go into the record. Rachel Amdur, MD, an internal medicine specialist at Northwestern University’s health system, says she frequently asks patients about any family history of blood clots, which can suggest extra risks in prescribing birth control pills and other medications. She also goes deeper into history if she suspects a patient may have celiac disease, leaving them unable to safely digest gluten. “I’ll try to find out if there were relatives who had any gastrointestinal symptoms, because they may have had an undiagnosed case of the disease,” she says.

If possible, find out what medications were prescribed for relatives’ illnesses, advises Neha Vyas, MD, a family medicine physician at the Cleveland Clinic. “Sometimes family members don’t remember exactly what diseases their relatives had, but they’ll remember the type of pill they took,” she explains. “That can be a good backdoor approach to figuring out what they had.”

And always get a rough age of onset for relatives’ diseases, Amdur says, because that can say a lot about whether there’s a strong genetic component to the illness. “If Grandpa had a stroke at 85, there may not be much to worry about,” she says. “But if it was stroke at 40, we’ll probably want to dig a little deeper.”

“Sometimes family members don’t remember exactly what diseases their relatives had, but they’ll remember the type of pill they took.”

Don’t hesitate to dig for information

Susan Zweizig, MD, who heads gynecologic oncology at the University of Massachusetts Memorial Medical Center, tells of a now-deceased early middle-age patient who recently came to her with ovarian cancer that was already at an advanced stage when diagnosed. It was only after the diagnosis that the patient found out she had a cousin who had also been hit by the disease some years earlier. “She didn’t know because that branch of the family hadn’t been speaking to her branch,” Zweizig says. “If that information had been available earlier, she would have been tested for the genetic mutation, and she could have had preventive surgery.”

There may be all kinds of information about relatives that’s potentially important to your health but may require more aggressive digging to find out because of family feuds, embarrassment, or ignorance. “When a patient says to me they feel weird about picking up the phone to ask a relative what kind of cancer someone had,” Zweizig says, “I tell them they have to get over it—this is their life.”

Among the information that may become unfortunately unspoken in the family: the fact that a relative was adopted, which means their genetics can’t affect you, or that a relative was of a different race or ethnicity than the rest of the family.

Doctors need to know if those sorts of risk modifiers belong in your records. “Some populations are at higher risk than others,” says Esteban Burchard, MD, a physician and researcher at UCSF. He notes, for example, that people of Jewish origin are more likely to carry gene mutations associated with breast cancer, while people of African origin tend to be at lower risk of Alzheimer’s from the gene most strongly associated with the disease.

Caveats

Even while they urge patients to play an active role in ensuring their family health histories are as complete as possible, doctors caution that there are important limits to what these histories say about a patient’s own current and likely future health.

Some diseases, such as infections and most types of leukemia, simply aren’t strongly associated with any known genetic links that passed through families. And Zweizig notes that those diseases that do have genetic components are rarely entirely genetic. “You can have the genes associated with the disease and not get the disease,” she says. “It’s not 100%.” That variation in whether or not a gene leads to a disease could be due to differences in environment, such as diet and air quality, or to other health factors, such as infections or immune system activity.

That means a grim-looking family history isn’t any sort of ironclad bad-health sentence. But it may help your doctor steer you to tests, treatments, and lifestyle changes that can make all the difference. “I tell my medical students that the easiest way to save a life is to take a careful family history,” Zweizig says.