Research suggests that genetic variations may be associated with ulcerative colitis (UC) and could be inherited. However, more research is needed to fully understand the role of genes in UC.

UC is a type of inflammatory bowel disease (IBD). The exact cause of the condition isn’t known.

However, research suggests that a family history of UC may be the biggest risk factor for developing the condition.

Several genetic variations have also been linked to UC by altering the body’s immune response or disrupting the protective barrier of the intestines.

Keep reading to learn more about the link between UC and genetics.

Genes consist of DNA containing specific proteins responsible for the makeup of our traits. This may include physical characteristics like hair color or how a specific cell in the body works.

Genetic information passes from the parent to the child.

The authors of a 2017 review suggest that over 50 hub genes may be associated with the development of IBD. Hub genes interact with many other genes in your body and play a key role in biological processes, such as immune regulation, inflammation, and gut health.

Gut health

Some gene variations may weaken or break down the protective lining inside the intestine.

If this happens, bacteria and toxins may come into contact with the epithelial surface of the large intestine. This could trigger an immune response, leading to inflammation and UC symptoms.

Immune regulation

Other genes linked to UC affect T cells. These cells help your immune system identify and attack bacteria and other foreign elements in your body. Certain genetic makeups may cause:

  • T cells to mistakenly attack the bacteria that typically live in your intestines
  • an aggressive response to pathogens or toxins passing through your colon

This excess immune response may contribute to the disease process in UC.

Specific genes

The authors of a 2019 study found that the most important hub genes involved in UC are:

  • CCR7
  • CXCL10
  • CXCL9
  • IDO1
  • MMP9
  • VCAM1

They also identified several pathways by which genes could trigger an immune response and inflammation.

However, more research is needed to fully understand how genes affect UC.

Researchers have looked into several factors that link genetics to an increased risk for UC. These include:

Clusters in families

UC tends to run in families. The Crohn’s and Colitis Foundation estimates that up to 30% of people with a close relative with UC may also develop the condition.

Research suggests that you’re four times more likely to develop UC if one of your immediate family members has the condition.

Twins

Twins offer an ideal window into the genetic roots of UC because their genes are more similar than those of other family members.

Research suggests that up to 19% of identical twins and up to 7% of fraternal twins will both have UC if one has the condition.

Ethnicity

UC is a condition that may affect everyone.

However, research suggests the following genes may play more of a role in the development of UC among people of certain racial or ethnic groups in the United States:

  • Asian: NUDT15
  • Black or African American: ZNF649, LSAMP
  • White or European descent: TPMT, HLA-DQA1*05

Results from the Centers for Disease Control and Prevention (CDC) 2015–2016 National Health Interview Survey (NHIS) suggest that IBD may not affect everyone similarly. For example, in the United States, IBD may affect:

  • 1.4% of non-Hispanic white people
  • 0.6% of non-Hispanic Black people
  • 1.2% of Hispanic people
  • 0.8% of non-Hispanic other people, including non-Hispanic American Indian and Alaska Native only, Asian only, Native Hawaiian and Pacific Islander only, and people of multiple race

It’s important to note that the NHIS survey didn’t differentiate between UC and Crohn’s disease, which is the other type of IBD. As such, exact figures for UC may differ.

Genes play an important role in the development of UC, but they’re just one part of the puzzle. Many people who receive a diagnosis of UC don’t have a family history of the condition.

Other possible risk factors for UC may include:

  • smoking
  • infection
  • having another autoimmune condition
  • taking certain medications, such as oral contraceptives, hormone replacement therapy, nonsteroidal anti-inflammatory drugs (NSAIDs), and antibiotics
  • living in urban areas
  • high dietary intakes of total fats and polyunsaturated fatty acids

Q:

If my sibling has UC, can I be genetically tested to check whether I have it, too?

Anonymous

A:

Typically, genetic testing isn’t a routine check for UC. A sibling with UC increases your risk of having the condition. However, because of the many gene variations that may be associated with a higher risk of having UC, there is currently no specific genetic test.

Making a diagnosis of UC is typically based on a combination of clinical history (family history, past medical history, environmental exposure history, and gastrointestinal symptoms and signs) and diagnostic tests (usually a combination of blood, stool, and imaging studies).

Stacy Sampson, DOAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

Can ulcerative colitis be passed on genetically?

A family history of UC may be the biggest risk factor for developing the condition. More research is needed to understand the link between genetics and UC.

What is the main cause of ulcerative colitis?

The exact cause of UC isn’t yet known. However, research suggests genetics, environmental factors, and your immune system may all play a role in UC.

Will I get ulcerative colitis if my mom has it?

Your chances of developing ulcerative colitis are greater if one of your immediate family members has the condition. However, many people who have UC in the family don’t develop it themselves.

Can I pass ulcerative colitis to my child?

There is a slight chance that your child will develop UC if you have the condition.

UC is a chronic inflammatory condition that affects your large intestine.

Research suggests that genetics may play a key role in the development of UC. However, more research is needed to determine the link between genetics and UC.