Genetics and Family History

A complete and accurate family history is one of the most powerful tools available for recognizing genetic conditions. A family history can help health professionals make a diagnosis or spot the possibility of a genetic condition occurring in family members. It is useful both in the diagnosis of genetic diseases that are somewhat common (e.g., breast cancer, colon cancer) and those that are more rare (e.g. cystic fibrosis, sickle cell disease).

The family history can also provide help in planning genetic testing: who needs to be tested, which tests could be most useful, what kind of answers tests could provide. It may even suggest possible courses of treatment. The identification of a genetic disorder through the family history could even lead health care professionals to recommend measures that could prevent the symptoms of the condition from appearing.

Statewide Genetics Services recommends that all individuals have an updated family history in their medical charts. Ask your health provider if you do not know whether or not one has been completed for you. The family history is often in the form of a pedigree , or a drawing of the family tree:

What do these symbols mean? Find out by reading Interpreting a Pedigree.

A complete history will include information on brothers, sisters, parents, grandparents, aunts, uncles, cousins, children, and possibly even more distant relatives (e.g. great-aunts and uncles, second cousins, etc.). The age and ethnicity of each family member should be recorded, as well as any medical conditions they may have. Even if it seems that their condition is not genetic, it should be included. If possible, include the age at which the condition first appeared. From this pedigree, we see that a woman by the name of Melissa is consulting a genetics professional, most likely because of a family history of a genetic condition known as neurofibromatosis. Melissa has an uncle, an aunt, three cousins, and a grandfather with the condition. Knowing this family history allows a genetics professional to estimate Melissa's risk of having neurofibromatosis herself, or passing it on to her children.

Sometimes people construct their own family histories over time. The links provided below are intended to help guide a person through the process of taking a complete and accurate family history, and provide more information on the subject:

• Family History Tool – The U.S. Surgeon General's Family History Initiative provides a tool called “My Family Health Portraitâ€� to help you gather and examine your family history. It creates a drawing of your family tree and chart of your family health history. These can be shared with family members or your health care provider, and may help you develop a health plan, including strategies for disease prevention.

• Genetic Family History – This website provides many links to other pages devoted to correctly taking a complete and accuracy family history, as well as to many sites emphasizing the importance of doing so.

• CDC Family History Webpage – This site provides activities, research and links to all things related to the use of a family history in health and medicine.