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PubMed This is a summary of 20 peer-reviewed journal articles Updated
Gastroenterology

Validation & Orientation: What is Gardner Syndrome?

At a Glance

Gardner syndrome is a variant of Familial Adenomatous Polyposis (FAP) caused by an APC gene mutation. It causes colon polyps alongside non-cancerous bone growths and skin cysts. With proactive screening and surgery, the high risk of colon cancer is highly preventable.

Receiving a diagnosis of Gardner syndrome can feel like a sudden storm, but it is important to know that you have entered a space of high-level medical clarity. Gardner syndrome is not a separate disease from Familial Adenomatous Polyposis (FAP); rather, it is a specific way that FAP shows up in the body [1][2].

In simple terms, Gardner syndrome means you have the colon polyps associated with FAP, plus certain features outside the colon, such as non-cancerous bone growths (osteomas) or skin cysts [3][4]. While the name may sound daunting, it provides your doctors with a roadmap for exactly what to monitor to keep you safe and healthy.

The Three Most Stabilizing Facts

When you are first diagnosed, the “100% cancer risk” statistic often causes a panic spiral. Here is the context that changes the narrative:

  1. The Risk is Preventable, Not Inevitable: While it is true that colon cancer is nearly certain if the condition is ignored, it is also true that with modern screening and proactive surgery, the risk of developing colon cancer can be reduced to nearly zero [5][6].
  2. You Have a Defined Roadmap: Because Gardner syndrome is so well-studied, there are international guidelines (such as those from NCCN and ESMO) that tell your doctors exactly when to screen and what to look for [7][8]. You are not “waiting for something to happen”; you are actively managing a known condition.
  3. Long-Term Survival is Excellent: Patients who adhere to their surveillance and treatment plans have an excellent long-term prognosis and a life expectancy that can mirror the general population [9][10].

Understanding the APC Gene

The root cause of Gardner syndrome is a change (mutation) in the APC gene [3][4]. To understand how it works, imagine the APC gene as a “brake pedal” for cell growth.

In a healthy body, the APC gene produces a protein that tells cells when to stop dividing [4]. In Gardner syndrome, that brake pedal doesn’t work perfectly. Because the cells don’t get the “stop” signal, they keep growing, which leads to the characteristic hundreds or thousands of polyps (small growths) in the colon and the extracolonic (outside the colon) features [1][11].

Features Beyond the Colon

The “Gardner” variant of FAP is identified by features that appear outside the digestive tract. Most of these are non-cancerous (benign) but are important clues for your care team:

  • Osteomas: Non-cancerous bony growths, often found on the jaw or skull [4].
  • Dental Anomalies: This can include extra teeth, impacted teeth, or small benign tumors of the jaw called odontomas [12][13].
  • Skin and Soft Tissue: You may notice epidermoid cysts (bumps under the skin) or fibromas (connective tissue growths) [14][15].
  • Desmoid Tumors: These are dense, non-cancerous growths of connective tissue. While they do not spread like cancer, they can be a significant part of your management plan [16][17].

Life Under Surveillance

Management of Gardner syndrome is highly personalized [11]. Your team will monitor you using endoscopy (using a camera to look inside the digestive tract) to keep track of polyp growth [18][19]. By catching changes early, your doctors can determine the best timing for interventions, ensuring that you stay ahead of the disease rather than reacting to it [18][20]. Management is a marathon, not a sprint, and with the right team, it is a journey you can successfully navigate.

Common questions in this guide

Is Gardner syndrome different from FAP?
Gardner syndrome is not a separate disease from Familial Adenomatous Polyposis (FAP). It is a specific way FAP presents, where patients develop both numerous colon polyps and features outside the colon, such as bone growths or skin cysts.
What causes Gardner syndrome?
The root cause is a genetic mutation in the APC gene. Normally, this gene acts as a brake pedal to stop uncontrolled cell growth. When it mutates, cells do not get the stop signal, leading to polyps and other growths.
What are the signs of Gardner syndrome outside the colon?
Patients may develop non-cancerous bony growths called osteomas, typically on the jaw or skull. Other signs include dental anomalies like extra or impacted teeth, epidermoid skin cysts, fibromas, and dense connective tissue growths known as desmoid tumors.
Can colon cancer be prevented if I have Gardner syndrome?
Yes. While the risk of colon cancer is nearly certain if the condition is ignored, modern surveillance and proactive surgery can reduce this risk to almost zero. Patients who follow their monitoring plans often have a normal life expectancy.
What kind of doctors will I need to see for Gardner syndrome?
Because the condition affects multiple areas of the body, you will need a multidisciplinary care team. This typically includes a gastroenterologist, a genetic counselor, an ophthalmologist, and specialized surgeons.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.What is the specific codon location of my APC gene mutation, and how does that influence my risk for desmoid tumors?
  2. 2.Based on my current polyp count and size, what is the recommended timeline for my first surgical intervention?
  3. 3.Who should be on my multidisciplinary care team (e.g., genetic counselor, GI specialist, ophthalmologist)?
  4. 4.Can you screen me for CHRPE (retinal pigment spots) to help confirm the clinical diagnosis?
  5. 5.What is the surveillance plan for monitoring my upper GI tract and other extracolonic areas?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (20)
  1. 1

    Gardner syndrome with giant abdominal desmoid tumor during pregnancy: a case report.

    Jin L, Tan Y, Su Z, et al.

    BMC surgery 2020; (20(1)):282 doi:10.1186/s12893-020-00944-z.

    PMID: 33183289
  2. 2

    A novel large deletion in the APC gene associated with Gardner syndrome in a Chinese family.

    Zhou J, Liang C, Qing D, et al.

    Revista espanola de enfermedades digestivas 2021; (113(3)):179-182 doi:10.17235/reed.2020.6974/2020.

    PMID: 33213169
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    Gardner syndrome with a giant mass in the thoracic cavity: a case report and analysis of the related complications.

    Yang D, Zeng X, Lv Y, et al.

    International journal of clinical and experimental pathology 2020; (13(8)):2158-2162.

    PMID: 32922614
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    A novel APC mutation associated with Gardner syndrome in a Chinese family.

    Zeng M, Yao X, Pan Y, et al.

    Gene 2024; (896()):148051 doi:10.1016/j.gene.2023.148051.

    PMID: 38043837
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    Case report: Initial atypical skeletal symptoms and dental anomalies as first signs of Gardner syndrome: the importance of genetic analysis in the early diagnosis.

    Antal G, Zsigmond A, Till Á, et al.

    Pathology oncology research : POR 2024; (30()):1611768 doi:10.3389/pore.2024.1611768.

    PMID: 38807857
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    The importance of early diagnosis of gardner's syndrome in dental examination.

    Adisen MZ, Okkesim A, Misirlioglu M

    Nigerian journal of clinical practice 2018; (21(1)):114-116 doi:10.4103/njcp.njcp_381_16.

    PMID: 29411735
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    Updated European guidelines for clinical management of familial adenomatous polyposis (FAP), MUTYH-associated polyposis (MAP), gastric adenocarcinoma, proximal polyposis of the stomach (GAPPS) and other rare adenomatous polyposis syndromes: a joint EHTG-ESCP revision.

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    The British journal of surgery 2024; (111(5)) doi:10.1093/bjs/znae070.

    PMID: 38722804
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    Japanese society for cancer of the colon and rectum (JSCCR) guidelines 2024 for the clinical practice of hereditary colorectal cancer.

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    International journal of clinical oncology 2026; (31(1)):1-66 doi:10.1007/s10147-025-02892-1.

    PMID: 41214301
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    Thirty-year compliance with a surveillance program for patients with familial adenomatous polyposis.

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    Familial cancer 2025; (24(1)):19 doi:10.1007/s10689-025-00441-3.

    PMID: 39890667
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    Familial adenomatous polyposis: complex patient management.

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    Attenuated Familial Adenomatous Polyposis: A Phenotypic Diagnosis but Obsolete Term?

    Anele CC, Martin I, McGinty Duggan PM, et al.

    Diseases of the colon and rectum 2022; (65(4)):529-535 doi:10.1097/DCR.0000000000002217.

    PMID: 34775416
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    Systemic considerations with pigmented fundus lesions and retinal pigment epithelium hamartomas in Turcot syndrome.

    Mokhashi N, Cai LZ, Shields CL, et al.

    Current opinion in ophthalmology 2021; (32(6)):567-573 doi:10.1097/ICU.0000000000000798.

    PMID: 34456292
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    Familial Adenomatous Polyposis.

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    Journal of pediatric genetics 2016; (5(2)):78-83 doi:10.1055/s-0036-1579760.

    PMID: 27617147
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    Extracolonic manifestations of Gardner syndrome: A case report.

    Blackwell MC, Thakkar B, Flores A, Zhang W

    Imaging science in dentistry 2023; (53(2)):169-174 doi:10.5624/isd.20230006.

    PMID: 37405201
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    Gardner syndrome initially misdiagnosed as bilateral breast malignancy: a case report and literature review.

    Qian R, Zhang G, Liu J, Kong W

    Frontiers in oncology 2026; (16()):1691293 doi:10.3389/fonc.2026.1691293.

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    Expert review of anticancer therapy 2024; (24(6)):363-377 doi:10.1080/14737140.2024.2344649.

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    Safety and efficacy of gamma-secretase inhibitor nirogacestat (PF-03084014) in desmoid tumor: Report of four pediatric/young adult cases.

    Takahashi T, Prensner JR, Robson CD, et al.

    Pediatric blood & cancer 2020; (67(10)):e28636 doi:10.1002/pbc.28636.

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    Endoscopic Surveillance after (Procto)Colectomy with Gastrointestinal Reconstruction in Patients with Familial Adenomatous Polyposis (FAP)-Principles, Goals and Practical Aspects Based on 12 Years of Observation.

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This page provides educational information about Gardner syndrome and FAP. It does not replace professional medical advice. Always consult your multidisciplinary care team for personalized screening and treatment plans.

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