Many Americans spend time tracing their family history. They might know the name of the village in Romania where their ancestors lived and when their great grandmother arrived in Ellis Island. What they're less likely to know about is their relatives' medical conditions.
While it's not always necessary to obtain health information about multiple previous generations, it is becoming increasingly helpful to know as much as possible about your family health history.
Thanks to the mapping of the human genome and advances in genetics research, scientists are now beginning to understand the genetic basis for more and more diseases. Some genetic disorders, such as Tay Sachs, are caused by a mutation in a gene, while other conditions, such as cancer and heart disease, are thought to result from a variety of genetic and environmental factors.
Gathering information about your family health history is the first step in assessing your genetic risk for different medical conditions. Some individuals, particularly those with a genetic disorder in the family, or who have multiple relatives who have had the same medical condition, may also consider genetic counseling.
Below, genetic counselor Robin Bennett, past president of the National Society of Genetic Counselors and a genetic counselor and manager at the University of Washington Medical Genetics Clinics in Seattle, discusses what information to include in your family health history and how genetic counseling can help people interpret the information.
Why is it important for someone to know their family health history? Knowing your family's health history can help you know if there are medical conditions in your family for which you should be screened differently than the average person. So, if you have a family history of a father or mother with colon cancer at age 45, you should probably be screened at an earlier age for colon cancer than age 50, when the average person gets offered colon cancer screening. And a man or woman with close relatives with birth defects or profound learning disabilities might be offered genetic screening tests before planning to have children.
Are there particular medical conditions that are important to track? There are some conditions that we clearly know are genetic such as Huntington's disease or cystic fibrosis. But there is also a need to ask about family history for common conditions like some cancers.
It can be helpful to know about family history any time there are multiple close relatives with a condition, particularly if it's occurring at a younger age than you would expect. For example, if you had a close relative who had breast cancer before they'd gone through menopause, which is usually around age 50, a family health history would be a good idea. Any sort of blindness that's happening in people before the age of 50 or so, heart disease in people in their 20s and 30s, and any history of sudden death that isn't explained would be cause for concern.
Ovarian cancer is something that usually doesn't run in families, but if you see people with breast and ovarian cancer in their family, or colon and ovarian cancer running in the family, then you'd be more worried that there might be something genetic causing those conditions, and there might be a genetic blood test that would help define whether you have a higher risk for those cancers.
Which relatives is it important to include, and how far back should you go? Certainly knowing information about your parents, your aunts and uncles, even your cousins can be helpful, and you should keep track of medical problems in children or grandchildren. Usually, knowing about three generations is very helpful, but any information is valuable.
One resource for gathering information about people who have died is death certificates. Oftentimes, even though someone might have died of heart disease, if they had cancer during their life it is noted on the death certificate. If they died of cancer, it might say how long they had their cancer or where the primary cancer was, even though they died of metastatic disease, which is cancer that has spread to another part of the body.
What kinds of information should be included in a family health history? You would want to know the age at which a person died and the cause of death. You should also know the age at which a person developed a medical condition and if they ever had surgery. For example, a female relative might have had her uterus or ovaries removed. With respect to cancer, you would want to know primary type of cancer and not just where it metastasized.
Do you have any suggestions for approaching relatives about a subject that could be sensitive? You can approach your relatives by saying, "I'm hoping to learn more about my medical family history so that I can potentially have this information for myself or my children." You can also emphasize that you're not trying to blame anyone for what's happened in the family. All families have medical conditions that run in multiple relatives, and it's no one's fault when you pass on a genetic condition.
What is the best way to present the information in a family health history? You can record family history using standard symbols called a pedigree, where squares are men and circles are women. Maybe you'd shade half of the symbol if a person had cancer and another half if they had heart disease. That way you can follow the conditions in the family and make a key that says when you got the information and what your symbols mean. Pedigrees are very graphic and when you take one to your health care providers it's very easy for them to see the information quickly versus having to read a bunch of records.
But the most important thing is to track that history down. The National Society of Genetic Counselors, the American Society of Human Genetics and the Genetic Alliance, which is a consumer support network for people who have genetic disorders in their families, is launching a family history information tool this fall, so that will be available on all of their websites. And the Centers for Disease Control is working on developing some family history tools.
Do you have any advice for people who might not have access to their family members, such as those who are adopted? Someone who doesn't know their biological family's health history should follow standard screening recommendations and have physical exams with their physician on a regular basis, as would be recommended for anyone of their age. And then they can start keeping track of medical information for their children.
When would you recommend that someone seek out a genetic counselor or other genetic health professional? Any time there is a medical condition that runs in the family that is of concern, a person can discuss it with their primary health care provider first.
Genetic counseling is mostly recommended when you see multiple relatives in more than one generation who develop a condition, or if there's something profound that's occurring in the first few years of life, like a birth defect or mental retardation or children that are being born and then having a decline in their abilities.
So those individuals might want to come and see a genetic counselor to see if they are a carrier for an inherited disorder. People who are having children with a cousin, which is actually very common in many parts of the world, have a slightly higher risk to have a child with a group of genetic conditions that are inherited in what they call an autosomal recessive pattern.
Women who are over the age of 35 at the time of pregnancy have a higher risk to have a child with an extra chromosome. Down syndrome is the most common example of that, and so they might be offered screening tests, which might be a combination of blood tests performed on the mother and the amniotic fluid that surrounds the fetus, and possibly ultrasound to image the fetus to help look for those kinds of problems.
How should family histories be interpreted? If the health history indicates that they might be at higher risk for a condition, a genetic counselor or physician can help to sort out what kinds of interventions might be offered them, whether that's some kind of screening like mammography or colonoscopy, or a genetic blood test.
There are many different kinds of genetic blood tests. A careful medical family history helps a genetic counselor determine if certain genetic tests will be helpful in making medical screening choices or in making plans for having children.
A genetic test does not always predict a certainty of developing a medical condition. Some people will live to an old age without developing the condition. Therefore it is important to have genetic tests interpreted by health professionals with experience with inherited conditions. Also, just because a test exists doesn't necessarily mean that everyone should have it.
Do any issues of insurance discrimination ever arise? It's a very common concern of families. In fact, I think in some ways it's affecting people getting health care because they're so concerned about it. But there's very little evidence in the United States, or even in the world, that genetic tests are being used in a discriminatory manner.
But there are laws to protect patients from genetic discrimination. You can't have your insurance plans taken away from you if you have a genetic disease. That includes health insurance, life insurance, disability insurance and long-term care. What could potentially happen is when you apply for a new policy, they might not insure you or they might charge a higher rate.
Currently, there's a big Senate bill where they're hoping to really solidify those protections. Discrimination based on genetic diseases will be considered just like discrimination based on your sex or race or sexual orientation.
Do you think at times people overplay the role of genetics in disease? There's a lot of evidence that people overestimate their risk, so I think seeing a genetic counselor is often more reassuring than scary. For example, parents often think the risks of having a child with a genetic condition are much higher than the actual chances may be. And a person may be afraid of developing the same disease a parent or grandparent had, but, again, their chances are often not much different than the average person's. Genetic counselors can help put such risks into perspective.