How Likely Is It That Your Family Members Or Kids Will Develop IBD?

IBD Genes Are Passed From Parent To Child, But The Risk Of IBD Is Complicated

Family At Dinner
If you have IBD, your family members are also at risk because IBD is in our genes. Image © Brand X Pictures / Getty Images

Question: How Likely Is It That Your Family Members Or Your Children Will Develop IBD?

Some people with inflammatory bowel disease (IBD) have a family member who also has IBD, but it's not always a parent or a sibling. Sometimes extended family members have IBD while no direct family members have the disease. The inheritability of IBD doesn't appear to be as simple as being passed from parent to child.

This leads to questions about exactly how IBD runs in families.

Answer: In this excerpt from UpToDate, an online reference source for doctors and patients, you can see that the question of how Crohn's disease and ulcerative colitis are inherited has a complicated answer.

How Likely Family Members Are to Have IBD: From UpToDate

"First-degree relatives of patients with IBD are approximately 3 to 20 times more likely to develop the disease than the background population. A family history of CD [Crohn's disease] is also associated with an earlier age of diagnosis in affected patients. However, the substantial majority of patients (>85 percent) have no family history of IBD."

Will Someone In Your Family Develop IBD?

First-degree relatives (which includes parents, children, and full siblings) of people with IBD are more likely to have IBD than are people from the general population who do not have a first-degree relative who has IBD.

The likelihood ranges from 3 to 20 times -- which is a very broad range.

In addition, Crohn's disease tends to be diagnosed at younger ages in people who have relatives with IBD. Yet, even though IBD is clearly passed through families, most people who have IBD do not have a relative who also has the disease.

In recent years, there have been several studies that seek to pinpoint the genes that carry the trigger for IBD. More than 100 genes have been identified as playing a role in developing IBD, however there may be several more that haven't been isolated yet. Clearly the role our genes play in the development of IBD is very complex, and it is not yet well understood.

Want to learn more? See UpToDate's topic, "Epidemiology and genetic and environmental factors in inflammatory bowel disease in adults," for additional in-depth medical information.


Snapper, Scott B; Podolsky Daniel K. "Epidemiology and genetic and environmental factors in inflammatory bowel disease in adults." UpToDate.  Accessed: Feb 2010.

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