Know Your Genetic Risk

Your family's health history holds critical clues.

5 min read

May 15, 2000 -- Mary Smith hadn't noticed the mass growing in her abdomen until her gynecologist discovered it during an exam. Unfortunately, Smith had missed several annual checkups, and her uterine fibroid had grown to a size that required surgery instead of other, less-invasive, treatment. When Smith called her mother in the Midwest to tell her about the surgery, she learned -- for the first time -- that her mother had had a similar experience when she was about the same age.

"If I had known about my family earlier, I would have gotten my checkups more often," says Smith. "And they might have found the fibroid sooner, while it was still small."

The diagnosis left Smith convinced that finding out about her family's medical history might be a good idea. She was fortunate that her mother was alive and lucid, and available to fill her in before it was too late.

Not everyone is so lucky. "Comedian Gilda Radner died of ovarian cancer in 1989. Unfortunately for Radner, she did not know until very late in the game that she had a strong family history of ovarian cancer," says Joan Kirchman Mitchell, chair of the National Genealogical Society's Committee on Family Health History.

"Her aunt, a first cousin, and a grandmother suffered from the same disease. In the population at large, a female's risk of ovarian cancer is around 1 in 70. Gilda's family health history changed her risk to around 1 in 2, or 50% -- a pretty dramatic change in the odds." Had Radner known about her greatly increased risk of cancer, says Mitchell, she might have sought treatment sooner.

Since Radner's death, researchers at the Gilda Radner Familial Ovarian Cancer Registry have determined that women with strong family histories of ovarian cancer develop the cancer at a younger age than the general population and that it occurs at progressively earlier ages in successive generations.

Other researchers have established that individuals having a family history of stroke or certain cardiac conditions are also more like to have these problems themselves. Genealogists, genetic specialists, and health care professionals all agree that knowing one's family health history is important for early identification and treatment or prevention of inherited disorders -- from cancer and heart disease to depression and other types of mental illness. You can also use a medical history to find out about your predisposition to a wide variety of other diseases.

There are some illnesses -- arthritis or Alzheimer's disease, for instance -- which may not currently lend themselves to either early detection or prevention. But in most cases, say researchers, the more you know about your family's health history, the better. And what if you do discover a serious condition that appears to run in your family? Don't panic, to start. Most family-related health problems are caused by a combination of factors, and you may not automatically have the same health problems experienced by several close family members.

If you've ever heard one of your older relatives reminiscing about recurring ailments shared by members of your family, then you've already taken the first step toward putting together a family health tree. Once you decide to officially launch a search, it's likely to be a long-term project.

Family health history researchers recommend tracing your health history back at least three or four generations, if possible. Mitchell says that it is vital to include relatives on the horizontal levels of the tree (your own and your parents' brothers and sisters -- or siblings) as well as those on the vertical levels (fathers, mothers, and grandparents on both sides).

Certain diseases, such as breast cancer, are inherited along gender-based lines, as are X-linked disorders such as hemophilia, in which males but not females are affected. Some conditions appear only in alternate generations, which is why it helps to know your exact relationship to any relative exhibiting signs of the ailment. The ethnicity and regional ancestry -- Northern Europe, Ireland, or Taiwan, for example -- of your family members is also very important, as certain conditions are linked to specific populations or locations.

You can collect information from relatives by giving them written questionnaires to complete or by conducting telephone or face-to-face interviews. In person, there's a chance to hear more details and to ask follow-up questions, says Debra Collins, a certified genetic counselor and associate clinical professor and director of the Genetics Education Center at the University of Kansas Medical Center. But some family members, she says, may be more comfortable writing things down than talking about them.

If you decide to organize the information you've gathered, the American Medical Association can get you started with their online personal and pediatric health history forms and a family health history diagram -- a tree-like diagram with special symbols for various life events such as births, deaths, marriages, adoptions, and illnesses. However you approach the subject, be sure to keep your records updated with new information about the current generation.

Sometimes you will run into problems as you attempt to collect information. First, memories can be faulty. Older relatives may simply have trouble remembering the details or exact diagnosis of someone else's -- or even their own -- illness. Second, some family members may want to cover up embarrassing details. Third, people may simply not know the facts. Family members may have heard more than one explanation for the same problem, says Debra Collins, or may not have shared medical details with each other in the first place. Misinformation can also be passed along until it's assumed to be true.

That leaves you with some discretionary work to do -- pressing relatives for more details, say, or adding some question marks to the chart. If everyone says Grandpa died of lung cancer -- and someone even quotes the family doctor to that effect -- it's more likely to be so than if one person points to lung cancer, another to pneumonia, and a third says that he just "up and died."

After you've created your family health history, you can give this information to your doctor. Mitchell recommends consulting a doctor promptly, in fact, if your medical history reveals two first-degree relatives (parents, siblings, or children) with the same cancer or one first-degree relative under the age of 50 with an illness usually associated with older people, such as cancer or heart disease.

You can also, of course, share the information with other family members. And if you continue to update and expand your family tree with new information as it comes along, it could become a living document, invaluable for future generations.

Claudia Willen writes about environmental issues and is the author of several books on computer programming. She is based in San Francisco.