Shaking family tree to find disease risk

My father always said he married my mother because she checked out as the best brood mare in the field. He was a physician as well as a horse breeder, so perhaps he can be forgiven for his rather harsh sounding views on choosing a mate. My mother evidently did.

Besides, it is certainly debatable on whether his methods produced the kind of uber-children he envisioned. My siblings and I have gratefully enjoyed good health thus far, but if you were to shake our family tree, you will find all manner of the ills that afflict mankind: heart disease, many kinds of cancer, even suicide.

Our family histories tell us a lot. But just because your grandaddy died of a heart attack ... or that very expensive genetic test you ordered up points to a gene for breast cancer ... should you be putting your affairs in order and dividing up the silver?

Not necessarily. Even though the newly minted genetic tests supposedly can identify killer genes lurking in our family tree, it is only the rare disease that is decided by a single gene: Hemophilia, Huntington's disease, Duschenne muscular dystrophy, Sickle-cell anemia. It's also important to remember that since genes are paired, a potentially lethal gene can be trumped by a dominant healthy gene.

Most of the diseases that concern us are "multifactorial," meaning there are many contributions to the condition becoming manifest.

Consider cardiovascular disease, cancer and diabetes. The genes that you inherit that may make you vulnerable to these killers are very much influenced by such other environmental factors such as our weight, what we eat and breathe, and age.

Lately, much has been published about "breast cancer genes." There are two that have been identified but, according to a special report from the University of Caifornia at Berkeley School of Public Health, there is no effective way of repairing these genes. Furthermore, women carrying these genes don't necessarily have a high risk for getting breast cancer. Of the women who have breast cancer, only 5 to 10 percent of them actually have these genes.

What is of special concern is if there is a pattern of early deaths in your family from a specific disease. Early onset of a disease points more clearly to a genetic influence.

Still, taking a hard look at your family medical history can be good for motivation and guide you in making adjustments to your lifestyle.

For example, if cancer runs in your family, you might want to pay more attention to diet; choosing one that is rich in fiber, phytonutrients, fruits and vegetables. If you are a woman and your mother suffered from osteoporosis, you may want to start a program of weight training sooner than later.

But it is also important to remember that we inherit more from our families than genes.

Consider obesity and depression. Although both can have a genetic link, they are highly influenced by the family culture we grow up in, such as how and why we eat, what amount we pile on our plate. Our parents also pass along coping strategies for stress and distress, such as alcoholism and perfectionism.

This is indeed a complicated question. It takes a qualified medical professional to decipher the many historical/genetic factors that make up our disease risk. If you are interested in exploring the subject on your own, one of the best resources is the Web site from the Harvard Center for Cancer Prevention: www.YourDiseaseRisk.Harvard.edu.

Dr. Michael O.L. Seabaugh, a Cape Girardeau native, is a clinical psychologist who lives and works in Santa Barbara, Calif. Contact him at mseabaugh@semissourian.com.