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.