Ulcerative colitis (UC) appears to run in families, suggesting that genetic factors may play a role. In addition, scientists have identified changes in a number of genes that may contribute to the development of UC.
However, experts are still working to establish the precise role specific genes play, if any.
While the exact cause of UC for each individual is unknown,
There is also a complex interplay of genetic susceptibility and environmental triggers. These may make a person more likely to develop an inappropriate immune response, resulting in inflammatory bowel disease (IBD) such as UC or Crohn’s disease.
This article discusses the genetic factors linked with ulcerative colitis and other triggers that may set off the disease.
Ulcerative colitis is a long-term condition affecting the gastrointestinal tract.
UC is a form of IBD and is an autoimmune condition. A fault in the immune system may cause the body to mistakenly attack healthy cells and fight nonexistent infections — viral or bacterial — leading to chronic inflammation in the inner surface of the colon. This inflammation results in sores, which doctors refer to as ulcers, developing in the intestines.
Symptoms vary from person to person, but they generally include:
- stool with pus or blood
- persistent diarrhea
- abdominal cramping or pain
- severe urge to go to the bathroom
- weight loss
People with UC will have periods of active disease, known as flares, and periods of remission, when they may not experience any symptoms.
Learn more from our IBD hub about living with ulcerative colitis.
UC also shares a genetic architecture with multiple sclerosis, another autoimmune-mediated disease, according to a 2021 study.
There are also other factors linking genetics to an increased susceptibility to having UC, including:
This study also demonstrates that 8–12% of people with IBD report a positive family history. Although, they concluded that Crohn’s disease may show a more frequent familial pattern than UC.
This study also described a cumulative effect, with the highest incidence reported in families where the disease affects three or more family members.
Since identical twins (monozygotic) share the same genetic material, twin studies help researchers understand which traits are due to genes and which are the result of environmental factors.
The risk for identical twins is significantly
The study also mentioned that children with parents who both have IBD have a higher risk.
The frequency of UC is much higher in certain ethnic groups.
The Ashkenazi Jewish population has a
IBD is also more
However, a meta-analysis showed a higher incidence of UC in people of South Asian descent who had immigrated to the United Kingdom and Canada. In this instance, environmental factors may play a more significant role in determining UC than other triggers.
Generally, IBD affects males and females equally. However, those diagnosed with UC when older are more likely to be males.
However, research from 2019 suggests that UC is more common in males than in females. In addition, males are more likely to receive a diagnosis between 50 and 60 years old.
A person’s environment seems to also play a role in increasing their risk of developing UC. Other triggers may relate to a person’s health and treatments from a young age, lifestyle, and levels of stress a person may experience.
These comparisons of a person’s environment relate to:
- population size
- population density
- economic and social factors from neighboring regions
Smoking has a stronger link with Crohn’s disease than UC. However, a
Diet may also trigger UC.
The study showed that the fecal microbiota of people on a specific carbohydrate diet had a higher biodiversity index — a healthier gut environment — than people eating a WSD.
Read about diets for people with UC here.
A 2016 study found a bi-directional relationship between stress and depression and IBD. A
Experts believe that the gut-brain axis plays a crucial role in the disease progression and relapse of IBD symptoms.
Read more on UC and the gut-brain link here.
Both forms of IBD may also occur in people who drank breast milk as a baby because breast milk
Other possible triggers linked to UC include:
- living in an extremely hygienic environment during childhood
- vitamin D deficiency
- certain medications, such as hormone therapy and nonsteroidal anti-inflammatory drugs
- air pollution
Doctors do not routinely request genetic testing to diagnose UC in current practice.
UC has no specific genetic test checks, especially since medical professionals associate many gene variations with the disease.
However, genetic markers show a great potential to identify the outlook and treatment outcomes of people with IBD. A
Ulcerative colitis is a chronic condition which may affect a person’s quality of life.
It has no known cure. However, treatments can help induce remission and reduce the severity of its symptoms. Most people require ongoing medications and lifestyle changes, while some may need surgery.
Current studies aim to better understand the biological processes that drive the disease to develop strategies that can help prevent its progression.
Ulcerative colitis is a complex disease caused by genetic and environmental factors. Certain genes put a person at risk of developing the disease. If a parent or sibling has UC this increases the risk of developing the condition within the family.
While it runs in families, it is crucial to understand that UC can occur in anyone, even in people with no family history of UC. There are other factors to consider, such as the environment someone grows up in, their lifestyle, factors such as stress and diet, along with other possible triggers.