Blood Samples

New guidelines on genomic testing for people with a rare type of Crohn’s or Colitis

The British Society of Gastroenterology (BSG) and the British Society of Paediatric Gastroenterology, Hepatology and Nutrition (BSPGHAN) have published new guidelines on the diagnosis and care of people with a rare type of Crohn’s or Colitis called monogenic inflammatory bowel disease (monogenic IBD).

What is monogenic IBD?

Crohn’s and Colitis can develop when immune cells enter your gut and damage the lining. In most people, we do not know exactly why this happens. It’s probably caused by a combination of changes in your genes, the bacteria that live in your gut, and something in the environment.

Rarely, some people have a type of Crohn’s or Colitis that is not caused by a combination of these things. Instead, it is caused by a change in a single gene. This is called ‘monogenic inflammatory bowel disease’ or monogenic IBD.

Why are the guidelines important?

Knowing that someone has monogenic IBD could help their hospital team work out how the condition might affect them or the best medicines to use. To check for monogenic IBD, a blood sample or samples taken from the gut can be tested to look for gene changes. This is called genomic testing.

The new guidelines will help children and adults with these rare forms of Crohn’s and Colitis get an accurate diagnosis using the best methods available. This will allow them to get the support they need and access the most appropriate care for their conditions.

Ruth Wakeman
Director of Services, Advocacy and Evidence, Crohn’s & Colitis UK

Genomic testing is expensive and it can take a long time to get the results. Most people with Crohn’s and Colitis do not need it because they are very unlikely to have monogenic IBD. In this case, having the tests would not change their treatment, and waiting for the results could slow down the start of treatment.

But for people who do have monogenic IBD, it’s important to find out. So we need a way to decide when genomic testing could be helpful, and when it is not needed. That is what the BSG and BSPGHAN guidelines do.

What do the guidelines say?

People who developed Crohn’s or Colitis after they were 6 years old rarely need genomic testing. It should mainly be offered to people with specific immune problems or other inherited problems. The guidelines recommend that consultants should consider genomic testing for:

  • People who developed Crohn’s or Colitis before they were 2 years old
  • People who developed Crohn’s or Colitis before they were 6 years old, especially if they have:
    • Other immune system problems
    • Frequent infections
    • Diarrhoea since birth
    • Cancer as a child or young adult
    • A close family member with suspected monogenic IBD
  • People with Crohn’s or Colitis who are so severely affected that they might need a stem cell transplant

The guidelines also set out recommendations on how the testing process should work, who should be involved, and what support should be available.

How was Crohn’s & Colitis UK involved in the guidelines?

The guidelines were developed by a group of experts in Crohn’s and Colitis, the immune system and genetics. They looked at all the latest evidence on genetic testing for Crohn’s and Colitis and came up with a list of recommendations. They graded each recommendation to show how certain they were in the quality of the evidence, and how strong the recommendation was. They then sent the recommendations to a wider group that included patient organisations and charities.

People from these organisations had the chance to say whether they agreed with the recommendations, and to raise any questions or concerns they had. The experts then adjusted the recommendations, taking into account everyone’s views. We took part in this process to help make sure the perspective of people living with Crohn’s or Colitis was taken into account.

The main guidelines are aimed at healthcare professionals. They are very technical and use a lot of scientific language. We also helped put together a reader-friendly summary of the guidelines for people living with Crohn’s or Colitis.

You can read the full guidelines online. The full reader-friendly version is on pages 6 to 8 of the supplementary material.


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We know it can be difficult to live with, or support someone living with these conditions. But you’re not alone. We provide up-to-date, evidence-based information and can support you to live well with Crohn’s or Colitis.

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