Image for family history article Sometimes it really is all in the genes. Knowing your family's medical history can alert you to potential problems and help you take precautionary measures.

Wendy Pickar believes family medical histories tell a powerful story. Her maternal grandfather died of ]]>brain cancer]]> at age 49. Her maternal grandmother died of ]]>thyroid cancer]]> at age 55. Her mother died of brain cancer at age 51. Her mother's sister died of brain cancer at 64. That aunt had a son who died of thyroid cancer at 13. Wendy is 40 and says she's thankful for every year. "Doctors tell me there's no medical proof brain tumors are hereditary," she says. "I don't believe it. Someday, they'll find a genetic flaw."

Ms. Pickar could well be correct. As researchers discover new genetic markers, certain individuals and families may be identified as having a higher than average risk for a variety of diseases. When it comes to your health, the apple doesn't fall far from the tree. Knowing your family medical history may save your life or the lives of your children and grandchildren.

"We already know family history is an important risk factor for several cancers," says Robert Dalton, MD, a hematologist/oncologist with St. Mary's/Duluth Clinic Regional Cancer Center in Duluth, Minnesota. " ]]>Breast]]> , ]]>colon]]> , thyroid, ]]>ovarian]]> , and ]]>prostate]]> cancers commonly run in families. In some cases, a family history of one of these cancers puts you at higher risk for the others."

Pick your poison. ]]>Heart disease]]> , ]]>stroke]]> , ]]>asthma]]> , ]]>diabetes]]> , ]]>arthritis]]> , and ]]>Alzheimer's]]> all tend to run in families. You won't necessarily be affected just because someone else in your family was, but under certain circumstances your risk might be increased. Inherited risk involves complex interactions among several genes and your environment. Your behaviors— ]]>smoking]]> , weight management, dealing with stress, ]]>heavy drinking]]> , exposure to toxins—influence whether you'll get a disease.

Flawed Genes: Gene Mutations

Some flawed (mutated) genes actually cause a disease. For example, if you inherit the gene mutation for ]]>Huntington's disease]]> , you'll get it. But many flawed genes merely make you more vulnerable to getting whatever disease is associated with it. The "p53 cancer gene," for example, makes families more susceptible to several cancers. ]]>Schizophrenia]]> and other behavioral problems run in families, too. Up to ¼ of the children of ]]>alcoholics]]> are likely to become alcoholics. There are even genes that are believed to play a role in ]]>obesity]]>.

Heredity may be a bigger factor than we currently know. For example, geneticists today will tell you a modest 5% of colon cancers are caused by genes, but that only reflects the gene markers we've discovered so far. With more research, scientists may discover that genetic causes play a larger role.

"We know that 20% of Alzheimer's cases are caused by a specific gene," says Diane Bierke-Nelson, a genetic counselor at St. Mary's/Duluth Clinic. "We know there are other genes involved, too. We just don't have them nailed down yet." As geneticists map and study all our DNA, the chemical blueprints that make us who we are, we'll know even more about heredity's power to shape our medical destinies.

A Gift to Your Family

Your family medical history is valuable to you and to future generations of your family, according to Ms. Bierke-Nelson. "Diagnoses will be more accurate and cures more likely. Recording your family medical history is a gift to your children and your grandchildren," she explains.

"It could save your life," says Dr. Dalton. "If we know what to look for, we may find it earlier when it's more treatable. Some people are alive today because they knew their family history."

Sleuthing Your Family Medical History

Medical histories for your first degree relatives are most important. First degree relatives include:

  • Parents
  • Brothers and sisters
  • Children

You probably already know a lot of your family medical history. For the rest, talk to relatives. They may be more open to discussing dates of diagnosis and causes of death if you explain the good deed you're doing for the whole family. Dig through old medical bills. Death certificates are available at your county records department for about $8-$15 a copy.

To request a medical record from a hospital or doctor, you must have written permission from the person whose record you want. If they are deceased, you must get written permission from the closest living relative.

How to Create a Family Medical Tree

Researching your family medical history is like genealogy. You can keep it simple or get completely carried away.

  1. Collect medical histories for your first degree relatives, this information includes:
    • Date of birth
    • Date of death
    • Cause of death
    • Major illnesses or surgeries
    • Date when major illness was diagnosed
  2. If you can, collect the same information about your second degree relatives:
    • Grandparents
    • Aunts and uncles
    • Step-brothers and sisters
    • Nieces and nephews
    • Grandchildren

As you build your family medical tree, remember these tips:

Get the Details

Be as specific as possible about cause of death and major illnesses. Knowing grandpa had cancer is a start. But what kind of cancer? At what age was he diagnosed? Did he develop a second cancer? Was it related to the first? Be wary of the “cancer spread” trap. Many cancers start in one organ but spread to another: often the brain, liver, lung, or bone. If you conclude that your relative had lung cancer when she really died of ovarian cancer that had spread to the lung, you will likely have misleading family history information. Unfortunately, sometimes it is hard or impossible to find out the true origins of a cancer.

Find out About Health Habits

Take it a step further if you like. Include significant habits and any unusual physical characteristics. Grandma Nelson's dowager's hump may mean her daughter and granddaughter are at risk for ]]>osteoporosis]]> . Uncle Fester's three-pack-a-day habit—not heredity—may be why he died of cancer.

Organize the Information on Paper

If you're artistic, draw a family medical tree. On the bottom of the tree, put your name, along with your sisters and brothers. On the row above, put your parents and their brothers and sisters. On the top row, put your grandparents. Put a square around each man and a circle around each woman. Leave enough room in each to summarize the information you've collected. Indicate marriages by connecting with lines.

What Does It All Mean?

Here are a few general guidelines for interpreting the medical information of your relatives:

  • The more generations an illness occurs in your family, the more at risk you are.
  • Two or more first degree relatives with the same or related cancers suggests an inherited risk. For example, if you have two first degree relatives with ovarian cancer, you have a 50% chance of getting it yourself. Keep in mind breast, ovarian, uterine, and colon cancers are genetically related.
  • The younger someone is when a disease develops, the more likely heredity played a role. If your mother or sister developed breast cancer before ]]>menopause]]> , your lifetime risk is one in three, instead of one in nine, as it is for other women.
  • A disease that strikes two or more relatives at about the same age is likely to be strongly influenced by heredity.
  • Clustering of cases of the same disease on one side of the family more strongly suggests a genetic influence than if a similar number of cases are scattered on both sides of the family.

What If You're at Risk?

If you suspect you're at risk for a "family disease," show your doctor your family medical history. Your doctor may suggest you undergo screening exams sooner than is normally recommended.

Genetic Counseling

Your doctor may refer you to a genetic counselor, such as Ms. Bierke-Nelson. "Genetic counselors are skilled at picking up on significant patterns and sketching out what they might mean to you," says Dr. Dalton. One to two hour visits with a counselor usually cost at least $125. Get a physician referral if you want to submit the cost to your health insurance.

Genetic counselors can talk to you about genetic testing and about "banking" your DNA. Ms. Bierke-Nelson encourages people over age 50 to bank their DNA if they have a strong family history of a specific disease.

DNA Banking

You can collect your DNA and save it for testing at a later date. Genetic tests are already available for more than 20 inherited diseases. Even if there isn't a genetic test for your "family disease," there probably will be soon. Your sample may save the life of your grandchildren or great-grandchildren.

Older family members at risk should bank their DNA now, according to Ms. Bierke-Nelson. Often, a sample from an older affected family member is needed to test younger, at-risk family members. "That's why it's so important for people in the 50-plus age group to take an interest in this," she says. "We'll be able to diagnose future generations early, when the disease can still be treated, even prevented."

Banking your DNA is easy and inexpensive. Kits are available for $30, so you can collect and store the samples yourself. The kit includes instructions and items for collecting samples of your hair, blood, and a few cells from inside your cheek. You can store these samples in envelopes wherever you keep important documents. Or, you can deposit your sample with a commercial gene bank that charges $100-$450 for indefinite storage.

Genetic testing however is a complex matter. It does not offer 100% predictability. It may give you a peace of mind, but it also can be a source of significant anxiety for some people. Before deciding, weigh all the benefits and risks, and talk to your doctor or a genetic counselor. Ultimately, you have the final decision.