Does bowel cancer run in your family? Test for the inherited cause.
One saliva sample checks 17 genes linked to inherited bowel (colorectal) cancer. These include the five Lynch syndrome genes, the most common inherited cause, and the genes behind polyposis conditions such as FAP. Knowing means you and your family can start screening earlier, when it does the most good.
The most common inherited cause of bowel cancer
Lynch syndrome is caused by a change in one of the mismatch repair genes (MLH1, MSH2, MSH6, PMS2) or in EPCAM. These genes normally fix small copying errors in DNA. When one isn't working, errors build up and cancers can develop at a younger age.
It affects around 1 in 300 people in the UK, but most don't know they carry it. As well as bowel cancer, Lynch syndrome raises the risk of womb (endometrial), ovarian, stomach, urinary tract and some other cancers.
The good news is that regular colonoscopy can find and remove polyps before they turn into cancer, which is why knowing matters.
17 genes, five inherited conditions
The Colorectal Cancer panel covers Lynch syndrome and the rarer polyposis conditions, where many polyps grow in the bowel.
Most bowel cancers start as a small growth called a polyp. In inherited conditions, polyps can form earlier, grow faster or appear in large numbers. That's why people who carry a gene change are offered earlier and more frequent colonoscopy.
| Condition | Genes | What it means |
|---|---|---|
| Lynch syndrome | MLH1, MSH2, MSH6, PMS2, EPCAM | Raised risk of bowel, womb, ovarian and other cancers, often under 50. Risk is highest with MLH1 and MSH2, and lower with MSH6 and PMS2. |
| Familial adenomatous polyposis (FAP) | APC | Hundreds to thousands of bowel polyps, usually from the teenage years. Without treatment, bowel cancer is almost certain. |
| MUTYH-associated polyposis | MUTYH, NTHL1 | Multiple polyps. These are recessive conditions: you need two changed copies, one from each parent. |
| Polymerase proofreading polyposis | POLE, POLD1 | Multiple polyps and early bowel cancer, sometimes womb cancer. |
| Juvenile and mixed polyposis | SMAD4, BMPR1A, GREM1 | Polyps in the bowel and stomach. GREM1 is more common in people with Ashkenazi Jewish ancestry. |
| Other syndromes | STK11, PTEN, TP53, RNF43 | Peutz-Jeghers, Cowden and Li-Fraumeni syndromes, and serrated polyposis |
All 17 genes
Family patterns that point to an inherited cause
- Bowel cancer in two or more close relatives on the same side of the family
- Bowel cancer diagnosed under 50
- Bowel cancer and womb (endometrial) cancer in the same family, or the same person
- Other Lynch-related cancers: ovarian, stomach, urinary tract, small bowel
- 10 or more bowel polyps found in you or a relative
- A relative with Lynch syndrome, FAP or another known gene change
- A relative's bowel or womb cancer tested "MMR deficient" or "MSI-high"
From home to report in about 3–4 weeks
Laboratory and quality
- UK laboratory accredited to ISO 15189:2022 by UKAS (Medical Laboratory No. 22262)
- CQC registered and part of GenQA external quality assessment
- Next-generation sequencing that finds single-letter changes, small insertions and deletions, and larger deletions or duplications, which are common in Lynch genes such as MSH2 and EPCAM
- Variants classified to ACMG, ACGS and CanVIG-UK standards and signed off by a registered clinical scientist
- Lab validation: specificity 99.99%, sensitivity 100% for single-letter changes and small insertions/deletions, 97.6% for larger deletions/duplications
What happens next
Only changes classed as pathogenic or likely pathogenic are reported. These are the changes known to raise cancer risk.
Your risk is higher than average. It does not mean you have cancer or will get it. Where clinically appropriate, a GCRAB-registered genetic counsellor explains your result, and your GP can refer you to NHS genetics and bowel surveillance services.
Reassuring, but your risk may still be above average if bowel cancer runs strongly in your family. Your GP can advise whether you need earlier colonoscopy, and you should take part in NHS bowel screening when invited.
Options if you have Lynch syndrome
People with FAP or other polyposis conditions follow different, specialist-led screening plans, often starting in the teenage years.
Everyday steps that lower bowel cancer risk
Each child of a parent with Lynch syndrome has a 1 in 2 chance of inheriting it.
If you test first and a change is found, your relatives can have a simpler, targeted test. Those who carry it can start colonoscopy in their 20s or 30s. Those who don't can be reassured.
Order the panel · £649Know the symptoms of bowel cancer
A gene test tells you about inherited risk. It doesn't check whether you have bowel cancer now. See your GP if you have:
- Blood in your poo or bleeding from your bottom
- A change in bowel habit lasting 3 weeks or more, such as looser poo or going more often
- Unexplained weight loss or extreme tiredness
- A pain or lump in your tummy
Take part in NHS bowel screening (a home FIT test every 2 years) when you're invited. Bowel cancer is the fourth most common cancer in the UK, and it's much easier to treat when it's found early.
Common questions
Questions about your result? Where it's clinically appropriate, a registered genetic counsellor will talk it through with you, and you can share your report with your GP or specialist.
What is Lynch syndrome?
An inherited condition caused by a change in one of the mismatch repair genes (MLH1, MSH2, MSH6, PMS2) or EPCAM. It raises the risk of bowel, womb and some other cancers, and is the most common inherited cause of bowel cancer.
How is this different from ColoAlert?
ColoAlert is a stool test that looks for signs of bowel cancer that may be there now. This genetic test looks at the genes you were born with, to see whether you have an inherited higher risk. They answer different questions, and some people use both.
Which panel should I choose?
Choose the Colorectal Cancer panel if bowel cancer, womb cancer or polyps are the main pattern in your family. Choose the 35-gene Comprehensive panel if breast, ovarian, prostate, pancreatic or skin cancer also run in the family.
What sample do I give?
Saliva, collected at home into a tube that keeps the DNA stable in the post. No blood test is needed.
How long do results take?
Usually about 15 working days after the laboratory accepts your sample, so allow 3–4 weeks from ordering.
Is genetic counselling included?
Yes, where your result makes it clinically appropriate. A GCRAB-registered genetic counsellor explains your result and talks through your options, and you receive a written summary.
Does a positive result mean I'll get cancer?
No. It means your risk is higher than average. Regular colonoscopy can find and remove polyps before they become cancer, which greatly lowers that risk.
Will I have to tell my insurer?
Under the UK Code on Genetic Testing and Insurance, insurers cannot ask you to take a predictive genetic test, or ask for or use predictive test results, apart from Huntington's disease for life cover over £500,000. Check the current code before you apply for cover.
Do I need a GP referral?
No. You can order directly. We recommend sharing your report with your GP.
Should my children be tested?
For Lynch syndrome, testing is not normally offered under 18, because colonoscopy doesn't start until the mid-20s. FAP is different: children in affected families are usually tested from around age 12, through NHS specialist services.
Order the hereditary bowel cancer panel
Saliva kit, prepaid return, a UKAS-accredited UK laboratory, and a clinical report by a registered clinical scientist.
Sources: NHS (Lynch syndrome); NICE DG27 and NG151; British Society of Gastroenterology/ACPGBI/UKCGG surveillance guidelines 2019; Cancer Research UK.
