Thanksgiving (search) is an ideal time for families to catalog their medical histories with a new government computer program that officials say can save critical time — and lives — for people who might inherit illnesses like breast cancer and heart disease.

"Knowing your family's history can save your life," Surgeon General Richard H. Carmona (search) said Monday. "You'll be amazed at what you learn."

Merely organizing a family's medical history often means power to predict and perhaps head off diseases prevalent in families even before they appear.

Health and genetic experts on Monday announced a free, Internet-based computer program that compiles information about six common diseases that often afflict several generations, such as heart disease, cancer and diabetes.

The software of "My Family Health Portrait" then prints out a graphic that can help a doctor assess the risk factors for family members and begin tests and treatment before any disease is evident, officials said.

Genetic factors contribute to the cause, length and response to therapy of almost every type of illness. So knowing family medical histories can help doctors tell people the risks of certain illnesses that run in the family.

While 96 percent of people think knowing such history is important to their health, only about a third have ever tried to catalog the information, according to the Centers for Disease Control and Prevention, which studied the issue in August.

The software, in effect, gives doctors a head start in calculating the risk of disease. The average doctor's visit is 20 minutes, which is too short to interview a patient, record three generations of medical history, assess disease risks and chart courses of action, said geneticist Francis S. Collins.

"Family history is central to taking advantage of the new genomic medicine, which is bubbling up all around us," said Collins, director of the National Human Genome Research Institute and a leader of the Human Genome Project.

Carmona acknowledged that filing family histories carries privacy concerns, such as the possibility an insurance company might see the records and raise a patient's premium or deny coverage. But family medical histories already sit in many patients' files, he pointed out.

Additionally, a bill passed by the Senate and working its way through the House would provide more protection by barring employers from using people's family histories in hiring or firing, Carmona said.

The family history initiative cost the government about $300,000, mostly for printing and software, said Larry Thompson, spokesman for the National Human Genome Research Institute.

The software can be downloaded at www.hhs.gov/familyhistory. A print version of "My Family Health Portrait" will be available in English and Spanish at more than 3,600 medical offices nationwide. Print versions also can be obtained from the Federal Citizen Information Center at 888-878-3256.