Genetic Diseases: What’s Lurking In Your Family Health History

genetic diseases

First her grandmother had breast cancer and died from it. Then her mom got it —and before she was 40. Plus, her family was descended from Ashkenazi Jews, who are 10 times more likely than other populations to have one of the genes that can cause breast cancer.

For L. Resnick, it wasn’t a question of if, but when she’d get breast cancer. So when she turned 40, she decided to get tested for the BRCA gene. Sure enough, she was a carrier.

“As I’d been under regular surveillance for years, I regularly researched options in the event cancer knocked on my door,” says Resnick, a 47-year-old mother of two from Seattle, Wash. “I knew I’d opt for a mastectomy and move on.”

For Resnick, knowing her family’s health history allowed her to be able to make an important decision about her own health. Shortly after learning she was a BRCA carrier, she chose to have a double mastectomy. A year later, since the BRCA gene also put her other reproductive organs at risk, Resnick opted for a hysterectomy as well.

Since 2004, as part of a national public health campaign, November has been known as Family History Month, and Thanksgiving itself as National Family History Day. Since then, the campaign has encouraged families to use the holiday season as a time to talk about their health histories. The information can be recorded and used to make informed decisions about preventive health screening and improve health behaviors. 

“Knowing your family health history risk can help you — if you act on it,” states the Centers for Disease Control and Prevention. “You can’t change your family health history, but you can change unhealthy behaviors, such as smoking, not exercising or being active and poor eating habits.”

There’s even a free online tool — phgkb.cdc.gov/FHH — made available from the U.S. Surgeon General’s office called “My Family Health Portrait,” which makes it easy to gather, record and organize a family health history. There are also various apps available to track the information on cellular devices.

Our Genes and Our Health

At a time when scientists are learning more about genetics and how our genes can affect our health, it’s important to know as much of your history as you can, says Dr. Luisel Ricks-Santi, director of Hampton University’s Cancer Research Center (HUCRC).

Knowing that there’s a family history of a certain genetic diseases, or that you could be a carrier for a certain gene, can change how diseases are managed and treated — and may even help prevent them in the first place. At HUCRC, research is focused on studying cancer as a disease of the genome, which is an organism’s complete set of DNA, including all of its genes.

As researchers have unlocked secrets of the human genome, they’ve learned that nearly all diseases have a genetic component. Genetic diseases are caused when there’s a change in the DNA sequence. Those diseases can sometimes be inherited from one’s parents and be present at birth, or be caused by mutations in a gene or genes during a person’s lifetime.

Variations in the genome can influence one’s risk of developing diseases as well as one’s responses to medications. That’s why one medication might work for someone but not for someone else. Knowing someone’s background helps doctors customize their approach to treating someone, rather than taking a one-size-fits-all type of approach.

What About Genetic Testing?

Online DNA tests — such as 23andme and ancestry.com — have become popular in recent years, helping people figure out their roots. Some of the tests also purport to tell you if you’re at risk for getting diseases. The problem is, the tests are not fail-proof, Ricks-Santi says. Take the BRCA genes believed to cause breast cancer — the online tests check for only a few of the genes, when in fact there are thousands of genes that could be the culprit. And not all hereditary breast cancers are caused by a single BRCA gene.

Although the tests can be useful, they can also lull someone into a false sense of security. “Those tests have limits,” Ricks-Santi says. “What we don’t want is someone to look at their test and say, ‘Oh, I’m not at risk for a heart condition, so I can eat anything I want.’ ”

The best way to use the genetic results from an online test is to share them with a physician or health provider who can help interpret the results correctly. Meeting with a genetic counselor can also be hugely beneficial because that counselor can help you figure out what further testing you might need.

Still, Ricks-Santi says, “having a family history and looking at that tree is still the most useful tool.”

How Can Knowing One’s History Help?

By knowing what happened to someone in the past, doctors and genetic counselors can use that information to look for characteristics and traits that could hint toward a certain disease or problem. And it might not always be a cut-and-dried diagnosis — those coffee-colored spots on grandpa’s body, for example, could be indicative of neurofibromatosis, a genetic disorder that causes tumors to form in the brain, spinal cord and nerves.

Or maybe your great-grandmother had a problem with her eyes, but no one ever really knew what it was. But maybe it was macular degeneration, an eye condition that causes vision loss. Genetic predisposition may account for half the cases of age-related macular degeneration in this country.

Cancer is an important one to know: How it manifested in a relative can affect how a future case is treated. “It can mean the difference between lumpectomy and radiation, and total mastectomy,” Ricks-Santi says. “If there’s a family history, there’s a chance a tumor could show up in the other breast, and if there’s a genetic component, there’s a chance it could show up as ovarian cancer.”

For Resnick, she now knows that since she carries the BRCA gene, her children could too. Her genetic counselor recommended that both her daughter and son get tested after they turn 25.

What if That Information Isn’t Easy to Get?

True, not everyone in your family might want to talk about their health background. Some people have trouble sharing information, such as a mental health diagnosis. But sometimes, all it takes is one person to start sharing to get the ball rolling.

“It takes one person, a brave person,” Ricks-Santi says. “And it’s not a one-time thing, it’s a yearly activity. … You can’t fall into the lull of, ‘It’s not in my family, I can’t have anything genetic.’ Because you can.”

Some of the diseases or conditions that have a genetic component:

What information should be included in a family medical history?

If possible, your family medical history should include at least three generations, including grandparents, parents, uncles, aunts, siblings, cousins, children, nieces, nephews and grandchildren. For each person, try to gather the following information:

  • Sex
  • Date of birth
  • Ethnicity
  • Medical conditions
  • Mental health conditions, including alcoholism or other substance abuse
  • Pregnancy complications, including miscarriage, stillbirth, birth defects or infertility
  • Age when each condition was diagnosed
  • Lifestyle habits, including diet, exercise and tobacco use
  • For deceased relatives, age at the time of death and cause of death

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Hampton University's Cancer Research Center

The mission of the Hampton University Cancer Research Center is to foster collaborative, interdisciplinary research and apply novel strategies to cancer research, while leveraging expertise and resources at Hampton University, to contribute to cancer prevention, carcinogenesis, and improving cancer outcomes and elimination of cancer disparities.