Genetics & Ulcerative Colitis

For some time, researchers have speculated that genetics plays a role in inflammatory bowel disease (IBD). These days, technology and advances in the study of the human body have enabled the scientific community to make possible connections. Current research suggests that certain genetic factors may increase the likelihood that a family member could develop ulcerative colitis (UC).

Current Research and What It Suggests*

Prevalence in Families: Research demonstrates that there is an increased occurrence of UC in families.^13,14,15,16 A survey of 17,713 people conducted on this website found that 14% of respondents with UC have an immediate family member with the condition.¹⁷

Prevalence in Siblings: Several studies suggest that there is an increased prevalence of IBD among siblings, up to 30 times that of the general population.^15,16

Prevalence among Identical Twins: In studies of twins with IBD, research shows that when one identical twin has IBD, there is about a 20% probability that the other twin has it. In considering fraternal twins, the same group of studies shows none of the siblings developed the disease. Those data also suggest that, since not all identical twins get IBD, environmental as well as genetic factors may play a role. ^15,16

Prevalence among Spouses: It is uncommon in families that both spouses develop IBD. Spouses do not share the same genetic makeup. This may be further evidence that genetics may play a role in the development of IBD. ^15,16

Prevalence in Offspring: When one parent has IBD, there's only about a 5% chance that their children will develop the disease.¹⁴ Recent observations suggest that there may be a higher risk of IBD among the offspring of parents who are both affected. ^15,17

*Please note that where possible, statistical information that is unique to ulcerative colitis has been used in this article. However, in some cases, statistical information is only available for IBD in general, and has been indicated as such.