Health condition
FAP and attenuated FAP
Familial adenomatous polyposis (FAP) carpets the colon with hundreds of adenomas from the teenage years and makes bowel cancer near-certain without surgery; attenuated FAP is its later, sparser cousin - both are APC gene conditions demanding registry-based care.
Why trust this guide
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Editorial team
Written by our editorial team from the UK sources listed on each page.
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Sourced from guidance
Checked against current NHS and UK specialist society guidance at the time of review.
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Current for 2026
Reviewed on 2026-09-27 with the next review scheduled for 2027-09-27.
Key facts
The essentials at a glance.
Which gene and test confirm it, who should be tested in the family, and which specialist to see.
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Caused by APC gene variants; autosomal dominant - attenuated FAP correlates with variants at particular positions in the gene
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Classical FAP: hundreds to thousands of colonic adenomas from adolescence; colectomy timed electively prevents cancer
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Attenuated FAP: tens of polyps, later onset - surveillance colonoscopy may substitute for or defer surgery
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Beyond the colon: duodenal polyps need scheduled upper endoscopy (Spigelman staging); desmoid tumours and thyroid surveillance also matter
Understanding the condition
What it is and what happens next.
What causes it, how it is confirmed, and the testing and specialist routes available in the UK.
What it is and how it presents
FAP is the condition that proved preventive surgery can abolish an inherited cancer: identified early through family testing, a young person undergoes surveillance until polyp burden dictates timing, then a planned colectomy - increasingly with excellent functional results - removes the main risk before any cancer forms. The attenuated form rewrites the schedule rather than the logic, with fewer polyps arriving later and colonoscopic control sometimes sufficient for years. Duodenal disease then becomes the long-term project either way.
Testing, surveillance and specialist care
UK care runs through polyposis registries that coordinate genetic confirmation, cascade testing of children and siblings from the early teens in classical FAP, colonoscopy and gastroscopy schedules, and surgical timing with experienced colorectal teams. Anyone with a cumulative count of ten or more adenomas deserves consideration of genetic testing rather than an assumption of bad luck. NHS clinical genetics services carry some of the longest waits in the health service, often many months for a first appointment, whereas private genetic testing and a specialist review can typically be arranged within around two weeks.
Seeing a specialist
Who to see, and how quickly you can be seen.
The specialist for this condition is usually a gastroenterologist at a polyposis registry, with clinical genetics. Your GP can refer you on the NHS, or you can arrange a private consultation directly.
A quiet reminder
This guide is for information, not medical advice.
Your GP knows your history and can tell you which parts apply to you. If in doubt, see them - and seek urgent care for any emergency symptoms.
Frequently asked
Common questions about FAP and attenuated FAP.
Quick, plain-English answers to what people ask us most.
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What does FAP and attenuated FAP mean?
FAP and attenuated FAP is a condition your doctor may diagnose based on your symptoms, medical history and, where needed, examination or test results. Understanding exactly how it applies to your situation is best done with a clinician who can look at your full picture rather than relying on general information alone.
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What are the risk factors for FAP and attenuated FAP?
FAP and attenuated FAP can arise from several different underlying mechanisms, and in many cases more than one factor contributes. Identifying likely causes usually forms part of the initial specialist work-up.
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What are the symptoms of FAP and attenuated FAP?
Symptoms of FAP and attenuated FAP vary from person to person and can range from mild and easily missed to significant enough to affect daily life. Because overlapping conditions can produce similar symptoms, a clinical assessment is the most reliable way to confirm what's actually going on.
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Can FAP and attenuated FAP cause complications?
Most cases of FAP and attenuated FAP are manageable with appropriate care, though, like many conditions, it can occasionally lead to complications if left unassessed or untreated. Your clinician can give you a realistic sense of the risks based on your specific presentation.
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Is FAP and attenuated FAP hereditary?
In most cases FAP and attenuated FAP isn't straightforwardly inherited, though family history can sometimes be a relevant background factor. A clinician can help you understand whether it's worth mentioning relatives' health when being assessed.
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Is there a cure for FAP and attenuated FAP?
FAP and attenuated FAP can often be managed effectively, and in some cases prevented or reversed, with the right combination of lifestyle changes, medication or other targeted treatment. A specialist will tailor the approach to your circumstances rather than applying a one-size-fits-all plan.
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How is FAP and attenuated FAP treated?
Treatment for FAP and attenuated FAP is usually built around the severity of your symptoms and any underlying cause found on assessment, and may involve lifestyle measures, medication, physiotherapy or, in some cases, a procedure. Your specialist will discuss the pros and cons of each option with you before agreeing a plan.
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What's the outlook for FAP and attenuated FAP?
The outlook for FAP and attenuated FAP varies widely depending on the underlying cause, how early it's diagnosed, and how it responds to treatment. Many people see significant improvement with appropriate care, and your specialist can give you a more personalised timeframe once they've reviewed your case.
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Could FAP and attenuated FAP be confused with another condition?
Because several conditions can share similar symptoms to FAP and attenuated FAP, clinicians often consider a short list of possibilities before confirming a diagnosis. This is one of the main reasons a proper assessment, and sometimes targeted tests, matters more than relying on symptoms alone.
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When should I see a doctor about FAP and attenuated FAP, and how quickly can I be seen privately?
It's worth seeking medical advice if symptoms of FAP and attenuated FAP are persistent, worsening, or affecting your daily life, rather than waiting for them to resolve on their own. NHS routine referrals for this kind of assessment can take anywhere from around 20 to 45+ weeks, whereas private consultants typically offer an appointment within about two weeks.