Gastric adenocarcinoma and proximal polyposis of the stomach

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ORPHA:314022OMIM:619182C16.9
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16Specialists8Treatment centers1Financial resources

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Overview

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) is a very rare inherited condition that causes hundreds of polyps (small growths) to develop in the upper part of the stomach, specifically in the fundic gland area. These polyps are found in the body and fundus of the stomach but spare the lower part (antrum) and do not typically involve the colon or rectum, which helps distinguish GAPPS from other polyposis syndromes. Over time, some of these stomach polyps can become cancerous, leading to gastric adenocarcinoma — a type of stomach cancer. GAPPS was first described in 2012 and is caused by specific mutations in the promoter region of the APC gene, which is well known for its role in other polyposis conditions like familial adenomatous polyposis (FAP). Because of the significant risk of developing stomach cancer, people diagnosed with GAPPS require close monitoring through regular upper endoscopy (a camera examination of the stomach). In many cases, doctors may recommend a prophylactic total gastrectomy, which is the surgical removal of the entire stomach, to prevent cancer from developing. This is currently the most effective way to eliminate the cancer risk. After surgery, patients can still eat but must make significant dietary adjustments. Early detection through genetic testing of at-risk family members is very important, as catching the condition before cancer develops greatly improves outcomes. There are currently no medications that can prevent the polyps from forming or progressing to cancer.

Also known as:

Key symptoms:

Hundreds of polyps in the upper part of the stomachStomach pain or discomfortNauseaFeeling full quickly after eatingUnexplained weight lossAnemia (low red blood cell count)Fatigue or tirednessVomitingLoss of appetiteBleeding in the stomach (which may cause dark stools)Stomach cancer if polyps are not monitored or removed

Inheritance

Autosomal dominant

Passed on from just one parent; each child has about a 50% chance of inheriting it

Age of Onset

Adult

Begins in adulthood (age 18 or older)

Orphanet ↗OMIM ↗NORD ↗

Treatments

No FDA-approved treatments are currently listed for Gastric adenocarcinoma and proximal polyposis of the stomach.

View clinical trials →

No actively recruiting trials found for Gastric adenocarcinoma and proximal polyposis of the stomach at this time.

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Specialists

16 foundView all specialists →
SK
Sun A Kim
Specialist
2 Gastric adenocarcinoma and proximal polyposis of the stomach publications
MI
Masaaki Iwatsuki
Specialist
3 Gastric adenocarcinoma and proximal polyposis of the stomach publications
CM
Chihiro Matsumoto
Specialist
3 Gastric adenocarcinoma and proximal polyposis of the stomach publications
HB
Hideo Baba
Specialist
3 Gastric adenocarcinoma and proximal polyposis of the stomach publications
SP
Shruthi R Perati
NEW BRUNSWICK, NJ
Specialist
3 Gastric adenocarcinoma and proximal polyposis of the stomach publications
KM
Koshi Mimori
Specialist
2 Gastric adenocarcinoma and proximal polyposis of the stomach publications
KY
Kozo Yoshikawa
Specialist
2 Gastric adenocarcinoma and proximal polyposis of the stomach publications
KO
Koichi Okamoto
Specialist
2 Gastric adenocarcinoma and proximal polyposis of the stomach publications
TT
Tetsuji Takayama
Specialist
2 Gastric adenocarcinoma and proximal polyposis of the stomach publications
MS
Mitsuo Shimada
Specialist
2 Gastric adenocarcinoma and proximal polyposis of the stomach publications
DS
Disha Sharma
BALTIMORE, MD
Specialist
2 Gastric adenocarcinoma and proximal polyposis of the stomach publications
GR
Gracia Viana Rodriguez
Specialist
2 Gastric adenocarcinoma and proximal polyposis of the stomach publications
GF
Grace-Ann Fasaye
Specialist
2 Gastric adenocarcinoma and proximal polyposis of the stomach publications
RL
Rachael Lopez
Specialist
2 Gastric adenocarcinoma and proximal polyposis of the stomach publications
CB
Cassidy Bowden
WEST JORDAN, UT
Specialist
2 Gastric adenocarcinoma and proximal polyposis of the stomach publications
AM
Andrew M Blakely, M.D.
COLUMBUS, OH
Specialist
PI on 5 active trials

Treatment Centers

8 centers
🏥 NORD

Baylor College of Medicine Rare Disease Center

Baylor College of Medicine

📍 Houston, TX

🏥 NORD

Stanford Medicine Rare Disease Center

Stanford Medicine

📍 Stanford, CA

🔬 UDN

NIH Clinical Center Undiagnosed Diseases Program

National Institutes of Health

📍 Bethesda, MD

🔬 UDN

UCLA UDN Clinical Site

UCLA Health

📍 Los Angeles, CA

🔬 UDN

Baylor College of Medicine UDN Clinical Site

Baylor College of Medicine

📍 Houston, TX

🔬 UDN

Harvard/MGH UDN Clinical Site

Massachusetts General Hospital

📍 Boston, MA

🏥 NORD

Mayo Clinic Center for Individualized Medicine

Mayo Clinic

📍 Rochester, MN

👤 Mayo Clinic Center for Individualized Medicine

🏥 NORD

UCLA Rare Disease Day Program

UCLA Health

📍 Los Angeles, CA

Financial Resources

1 resources

VYLOY

Astellas

Stomach Cancer

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Travel Grants

No travel grants are currently matched to Gastric adenocarcinoma and proximal polyposis of the stomach.

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Community

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Latest news about Gastric adenocarcinoma and proximal polyposis of the stomach

1 articles
Clinical trialUNITERAREApr 3, 2026
New Recruiting Trial: Comparison of Molecular-Genetic Concordance of the Primary Tumor and Brain Metastases of Gastroesophageal Cancers
Researchers are looking for patients with gastroesophageal cancer (cancer of the food pipe and stomach) that has spread to the brain. This study will compare th
See all news about Gastric adenocarcinoma and proximal polyposis of the stomach

Caregiver Resources

NORD Caregiver Resources

Support, advocacy, and financial assistance for caregivers of rare disease patients.

Mental Health Support

Rare disease caregiving can be isolating. Connect with counseling and peer support.

Family & Caregiver Grants

Financial assistance programs specifically for caregivers of rare disease patients.

Social Security Disability

Learn how rare disease patients may qualify for SSDI/SSI benefits.

Questions for your doctor

Bring these to your next appointment

  • Q1.What is my personal risk of developing stomach cancer based on my specific mutation and family history?,How often should I have upper endoscopy surveillance, and what are you looking for during each exam?,At what point would you recommend preventive removal of my stomach, and what does that surgery involve?,Should my family members be tested for this genetic mutation, and at what age should testing begin?,What nutritional supplements and dietary changes will I need if I have my stomach removed?,Are there any clinical trials or new treatments being studied for GAPPS?,How will this condition affect my ability to work, exercise, and live a normal life long-term?

Common questions about Gastric adenocarcinoma and proximal polyposis of the stomach

What is Gastric adenocarcinoma and proximal polyposis of the stomach?

Gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) is a very rare inherited condition that causes hundreds of polyps (small growths) to develop in the upper part of the stomach, specifically in the fundic gland area. These polyps are found in the body and fundus of the stomach but spare the lower part (antrum) and do not typically involve the colon or rectum, which helps distinguish GAPPS from other polyposis syndromes. Over time, some of these stomach polyps can become cancerous, leading to gastric adenocarcinoma — a type of stomach cancer. GAPPS was first described in 2012

How is Gastric adenocarcinoma and proximal polyposis of the stomach inherited?

Gastric adenocarcinoma and proximal polyposis of the stomach follows a autosomal dominant inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.

At what age does Gastric adenocarcinoma and proximal polyposis of the stomach typically begin?

Typical onset of Gastric adenocarcinoma and proximal polyposis of the stomach is adult. Age of onset can vary across affected individuals.

Which specialists treat Gastric adenocarcinoma and proximal polyposis of the stomach?

16 specialists and care centers treating Gastric adenocarcinoma and proximal polyposis of the stomach are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.

What treatment and support options exist for Gastric adenocarcinoma and proximal polyposis of the stomach?

1 patient support program are currently tracked on UniteRare for Gastric adenocarcinoma and proximal polyposis of the stomach. See the treatments and support programs sections for copay assistance, eligibility, and contact details.