Lynch Syndrome: Symptoms, Causes, Inheritance, Diagnosis, and Screening
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Lynch syndrome is an inherited genetic condition caused by a mutation in one of five DNA-repair genes (MLH1, MSH2, MSH6, PMS2, or EPCAM). It raises the lifetime risk of several cancers, especially colon and endometrial cancer, which often develop earlier than in the general population. There is no cure, but regular screening, with colonoscopy starting at ages 20 to 25, finds cancers early, and most people who follow a recommended care plan can expect a near-typical lifespan [1][2].
Quick Answer: What is Lynch syndrome?
Lynch syndrome is an inherited genetic condition that raises the risk of many cancers, most notably colon and endometrial cancer. Each child of an affected parent has a 50% chance of inheriting it. It usually causes no symptoms until cancer develops. There is no cure, but regular colonoscopy and other screening lower the risk, and genetic testing confirms it. [1] [2]
What the research says
Cancer risks differ by gene and sex, and survival after the most common cancers is good. In a prospective database of 6,350 carriers of pathogenic mismatch repair variants (51,646 follow-up years, 1,808 cancers), MLH1 and MSH2 carriers had high and similar colorectal, endometrial, and ovarian cancer risks, and older MSH2 carriers also had higher risks of upper urinary tract, upper gastrointestinal, brain, and particularly prostate cancer. MSH6 carriers had a high endometrial cancer risk but only a modestly increased colorectal risk, no significant increase in risk was shown for PMS2 carriers, and 10-year crude survival was over 80% after colon, endometrial, or ovarian cancer (Dominguez-Valentin et al., Genet Med, 2020 [3]).
Regular colonoscopy more than halved colorectal cancer in families with hereditary nonpolyposis colorectal cancer. In a 15-year controlled trial in 22 families, colorectal cancer developed in 8 of 133 screened people (6%) compared with 19 of 119 unscreened controls (16%), a 62% reduction. All cancers in the screened group were local, with no colorectal cancer deaths compared with 9 in the control group, and overall deaths were 10 versus 26. Screening was done every 3 years in this study; current guidance is every 1 to 2 years (Järvinen et al., Gastroenterology, 2000 [5]).
Daily aspirin lowered colorectal cancer in a long-term randomized trial. In the CAPP2 trial, 861 people with Lynch syndrome took 600 mg of aspirin daily or placebo and were followed for a mean of 10 years. Colorectal cancer developed in 40 of 427 people on aspirin (9%) and 58 of 434 on placebo (13%), a hazard ratio of 0.65 (95% CI 0.43 to 0.97), with no effect on non-colorectal Lynch cancers. Whether aspirin suits you, and at what dose, is a decision for you and your healthcare professional (Burn et al., Lancet, 2020 [4]).
What is Lynch syndrome?
Lynch syndrome is a genetic condition that raises the risk of many types of cancer, especially colon cancer and endometrial cancer. It is inherited, which means it is passed down through families, and cancers caused by Lynch syndrome often occur earlier in life than in the general population [1].
The condition used to be called hereditary nonpolyposis colorectal cancer (HNPCC), a term for families with a strong history of colon cancer with or without colon polyps. Early research split HNPCC into Type 1 (colon cancer only) and Type 2 (colon cancer plus cancers such as uterine, ovarian, or stomach cancer). Those distinctions are no longer used. "Lynch syndrome" is now preferred because it reflects the underlying genetic cause and recognizes that the syndrome raises the risk of several cancer types, not just colon cancer [1].
The practical takeaway is that Lynch syndrome is a risk-management story. Regular screening tests such as colonoscopy can find cancers early, when they are most treatable, and some people also consider preventive surgery or medicines to lower their risk [1].
Why does family history matter more than symptoms in Lynch syndrome?
Lynch syndrome usually causes no symptoms until cancer develops, so family history is often the first clue that someone has the condition. Many people feel healthy for years and only learn they have the condition after a family member is diagnosed. When symptoms appear, they come from the cancer itself, not from the syndrome [1]:
Cancer type | Possible symptoms |
Colon cancer | Blood in the stool, changes in bowel habits, belly pain, unintentional weight loss |
Endometrial cancer | Vaginal bleeding or pelvic pain that is not typical |
Stomach or small bowel cancers | Indigestion, nausea, unexplained anemia |
Urinary tract cancers | Blood in the urine |
People with Lynch syndrome also may develop cancer at younger ages than usual, or more than one type of cancer during their lifetimes. Because early cancers may not cause clear symptoms, regular screening tests are the most reliable way to find and treat cancer early [1].
When to see a doctor. If a member of your family has Lynch syndrome, tell your healthcare professional and ask to see a genetics specialist, such as a genetic counselor, who can explain the condition and whether genetic testing is right for you [1].
Which five DNA repair genes cause Lynch syndrome?
Lynch syndrome is caused by an inherited change, called a pathogenic variant or mutation, in one of five genes that repair DNA damage: MLH1, MSH2, MSH6, PMS2, and EPCAM. These are known as DNA mismatch repair (MMR) genes, and their job is to find and correct small copying errors in DNA [1].
If one copy of an MMR gene is changed, the body can still repair DNA using the healthy copy. But if the healthy copy is later damaged or lost, for example in a cell in the colon, DNA errors begin to build up and can cause cells to grow out of control and become cancer [1].
If one parent has a mutation in one of these genes, there is a 50% chance that each biological child will inherit it. This is called an autosomal dominant inheritance pattern [1].
Each biological child of a parent with a Lynch syndrome gene change has a 50% chance of inheriting it.
What are the risk factors for Lynch syndrome?
You can develop Lynch syndrome only if you inherit a genetic change that affects one of the DNA repair genes MLH1, MSH2, MSH6, PMS2, or EPCAM [1].
Risk factor | What it means |
Affected parent, sibling, or child | A first-degree relative diagnosed with Lynch syndrome |
Early or multiple family cancers | Strong family history of Lynch-linked cancers, including colon, endometrial, and uterine cancers, before age 50 |
Known family gene change | A mutation in one of the mismatch repair (MMR) genes passed down in your family |
Lynch syndrome can also occur in a family without a known history if the gene change happens for the first time. This is known as a de novo variant [1].
Which cancers does Lynch syndrome raise the risk for?
Lynch syndrome increases the lifetime risk of several types of cancer, and these cancers often occur at a younger age than in the general population [1]:
Body system | Associated cancers |
Digestive | Stomach, small bowel, and colon cancers |
Female reproductive | Endometrial, uterine, and ovarian cancers |
Urinary | Renal pelvis (center of the kidney), bladder, and ureter cancers |
Biliary | Gallbladder and bile duct cancers |
Other | Pancreatic, brain, prostate, and sebaceous skin cancers |
Current research has not shown a clear link between Lynch syndrome and breast cancer. Some breast cancers in people with Lynch syndrome show the same DNA repair gene changes, but experts agree there is not enough evidence to consider breast cancer part of the Lynch syndrome cancer spectrum [1].
Other inherited syndromes also raise colon cancer risk [1]:
Familial adenomatous polyposis (FAP): hundreds to thousands of colon polyps, with a nearly 100% chance of colorectal cancer if the colon is not removed.
Gardner syndrome: a type of FAP that also causes noncancerous skin lumps, extra bone growth, and soft tissue tumors.
Li-Fraumeni syndrome: greatly raises the risk of many cancers at a young age but is not related to the gene changes seen in Lynch syndrome.
Muir-Torre syndrome: a rare form of Lynch syndrome that adds small skin tumors in oil glands.
How is Lynch syndrome diagnosed through family history and testing?
Diagnosing Lynch syndrome often starts with a review of the family's history of cancer, which can lead to testing of cancer cells and genetic testing. Your healthcare professional may advise genetic testing if one or more of the following are true [2]:
More than one blood relative had a cancer linked to Lynch syndrome, including colon or endometrial cancer (others include stomach, ovaries, pancreas, brain, small intestine, ureters, gallbladder, bile duct, bladder, skin, and the renal pelvis).
One or more blood relatives had a Lynch-related cancer before age 50.
One or more blood relatives have had more than one type of Lynch-related cancer.
More than one generation of your family has had the same kind of cancer.
Testing cancer cells first
If you or someone in your family has had cancer, a sample of the cancer cells may be tested before genetic testing [2]:
Test | What it looks for |
Immunohistochemistry (IHC) | Dye stains cancer cells to show whether they have certain proteins; missing proteins may point to Lynch-related gene changes |
Microsatellite instability (MSI) | Errors in microsatellites (pieces of DNA), which may occur in people with Lynch syndrome |
Positive IHC or MSI results can show that the cancer cells have genetic changes connected to Lynch syndrome, but they do not tell for sure whether you have the condition. Some people have these changes only in their cancer cells. People with Lynch syndrome have the specific change in all the cells in their bodies, which is why genetic testing is needed [2].
Genetic testing
Genetic testing looks for changes in the genes that can cause Lynch syndrome. It is usually done with a blood sample, although saliva or a cheek swab (buccal swab) is sometimes used [2].
Result type | What it means |
Positive | A gene change that causes Lynch syndrome was found. It does not mean you will get cancer, but your risk of some cancers is higher than in people without Lynch syndrome. Risk may depend on which gene runs in your family. |
Negative | Gene changes were not found, so you probably do not have Lynch syndrome. You could still have a higher cancer risk because of a strong family history. |
Unclear | A gene change was found that professionals are not sure about, called a variant of unknown significance. A genetics professional can help interpret it. |
Important warning about at-home tests: there are no reliable at-home testing kits for Lynch syndrome. At-home DNA tests can provide ancestry or general health information, but they cannot reliably detect Lynch syndrome. These kits usually check only a few common genetic markers and do not include the detailed testing needed to find changes in the MLH1, MSH2, MSH6, PMS2, or EPCAM genes. For accurate results, genetic testing should be done through a healthcare professional or genetic counselor, who can order a medical-grade test from a certified laboratory and interpret the results [2].
Diagnosis moves from family history, to testing the cancer cells, to genetic testing ordered by a healthcare professional.
How is Lynch syndrome treated and managed with screening?
Lynch syndrome cannot be cured because it is an inherited genetic condition. Instead, people rely on cancer screening and sometimes preventive surgery or medicines. If cancer is found early, when it is small, treatment is more likely to be successful [2]. Screening is especially important because cancers in Lynch syndrome can develop at a younger age and get worse more quickly than in the general population. The tests you need depend on the gene you carry and the cancers that run in your family [2].
Cancer screening recommendations
Cancer type | Screening recommendation |
Colon | Colonoscopy starting at ages 20 to 25, or 2 to 5 years earlier than the youngest colorectal cancer diagnosis in the family; repeated every 1 to 2 years |
Endometrial | Screening may begin at ages 30 to 35; endometrial biopsy every 1 to 2 years; some experts also use ultrasound imaging |
Ovarian | Routine screening has not been shown to save lives; it often misses early cancers and can lead to false alarms or unnecessary surgery |
Stomach and small bowel | Upper endoscopy may begin between ages 30 and 40, repeated every 2 to 4 years; earlier if there is a family history of upper digestive cancers or risk factors such as stomach polyps or Barrett's esophagus |
Urinary tract | Annual urine test for blood or other changes beginning at ages 30 to 35, especially for people with MSH2 variants or a family history of urinary tract cancers |
Pancreatic | MRI or endoscopic ultrasound at a high-risk center if several blood relatives had pancreatic cancer; usually begins at age 50, or 10 years earlier than the youngest family diagnosis |
Skin | Skin exam every 1 to 2 years by someone familiar with sebaceous (oil gland) tumors; timing is individualized |
Brain | No set schedule; watch for neurological symptoms such as persistent headache, vision changes, hearing loss, dizziness, balance trouble, or arm or leg weakness, and seek care right away |
Prostate | Men have a risk five times higher than men without Lynch syndrome; annual PSA testing is recommended beginning at age 40, particularly with MSH2 or MSH6 mutations |
Breast | No clear link; follow standard population guidelines based on individual and family history |
A colonoscopy cannot diagnose Lynch syndrome, but it can find and remove growths before they become cancer [2].
Preventive surgery and medicines
In some situations, surgery or other treatment to reduce cancer risk may be a good choice. Talk about the benefits and risks with your healthcare professional [2].
Cancer to prevent | Risk-reducing option |
Endometrial cancer | Hysterectomy (surgery to remove the uterus) prevents endometrial cancer; a hormone-releasing intrauterine device (IUD) is another option and also prevents pregnancy |
Ovarian cancer | Oophorectomy (surgery to remove the ovaries) greatly lowers the risk; birth control pills taken for at least five years also lower the risk |
Colon cancer | Colectomy (surgery to remove most or all of the colon) lowers colon cancer risk |
Aspirin for prevention. Some research suggests that taking an aspirin every day may lower the risk of cancer in people with Lynch syndrome, and a baby aspirin daily is enough to help prevent colorectal cancer, according to Mayo Clinic. Talk with your healthcare professional to decide whether aspirin could be a good choice for you [2].
Healthy habits and self-care
These everyday habits support overall health while living with Lynch syndrome: eat a balanced diet, exercise regularly, do not smoke, limit alcohol, maintain a healthy weight, and keep up with all medical appointments, including cancer screenings [2].
Prognosis: A near-typical lifespan is possible
People with Lynch syndrome have a higher chance of developing certain cancers at younger ages, often before age 50. In the past, many were diagnosed only after symptoms appeared, leading to worse outcomes. Today, thanks to regular colonoscopies, endometrial screening, and preventive surgeries, cancers are more often found early or prevented altogether. Most people who follow recommended care plans can expect a near-typical lifespan [2].
Research on the horizon
There are no treatments that cure or reverse Lynch syndrome itself, but researchers are studying new approaches. Cancer vaccines are being developed to teach the immune system to recognize and attack atypical cells before they turn into cancer; early studies show they can safely trigger immune responses, but they are still in clinical trials. Precision prevention research shows cancer risks vary depending on which gene is changed, so future care may tailor when to start screening and how often to each person's exact mutation and family history [2].
How can people live with Lynch syndrome and find support?
Learning you have Lynch syndrome can be stressful and may cause worry about your future. Over time, most people find ways to cope [2].
Learn about the condition. Gather information so you can make informed decisions about your care. Write down your questions and bring them to appointments, and ask your healthcare team for reliable resources.
Handle common concerns with professional help. Having Lynch syndrome raises questions about other parts of life:
Concern | Guidance |
Privacy | You may worry about how your diagnosis could affect insurance or your job. A genetics professional can explain your legal protections. |
Children | A genetics professional can help you understand inheritance, discuss testing, and guide how and when to talk with your children. |
Family | A genetics professional can help you plan conversations with blood relatives about risks and testing options. |
Find support. Talk with someone you trust, such as a friend, family member, counselor, social worker, or clergy member. Ask your healthcare team about support groups in your area, and look for online communities where you can connect with others for support, practical information, and answers to everyday questions.
How should you prepare for a Lynch syndrome appointment?
If you have symptoms that worry you, make an appointment with a healthcare professional. If Lynch syndrome is suspected, you may be referred to a genetics professional, such as a genetic counselor, who can help decide whether genetic testing would be useful and interpret the results [2].
Step | What to do |
Gather your medical records | Bring them to your appointment if you have had cancer |
Ask family members who have had cancer | Write down their cancer types, treatments, and ages at diagnosis |
Take a family member or friend | Someone else may remember information you miss during the appointment |
Write down questions | Bring them to ask your care team |
A genetics professional will likely ask about your health history and your family's: whether you or family members have had cancer, the age of each diagnosis, and whether anyone has had genetic testing. Helpful questions to ask include: What causes Lynch syndrome? How is it passed through families? What are my chances of having it if a family member does? What will test results tell me, and how long do they take? What is my cancer risk if the result is positive? What tests find cancers early? Does a negative result mean I will not get cancer? What do my results mean for my family? How much does testing cost, and will insurance cover it? What laws protect me from discrimination? Is it OK to decide against testing? [2]
What is the bottom line on Lynch syndrome?
Lynch syndrome is an inherited condition that raises the lifetime risk of several cancers, especially colon and endometrial cancer, often before age 50. It usually causes no symptoms of its own, which is why family history matters so much: if Lynch syndrome or early, multiple, or repeated cancers run in your family, a genetic counselor can help you understand your risk and whether genetic testing is right for you.
There is no cure, but the condition is highly manageable. Colonoscopy starting at ages 20 to 25, targeted screening for other cancers, and in some cases preventive surgery, hormones, or daily aspirin improve the odds of finding cancer early or preventing it. If Lynch syndrome runs in your family, do not wait for symptoms. Talk to a healthcare professional or genetic counselor about testing and build a screening plan together. Your family history is information: use it.
Frequently Asked Questions
What is Lynch syndrome?
Lynch syndrome is an inherited genetic condition that raises the lifetime risk of several types of cancer, especially colon cancer and endometrial cancer. It is passed down through families, and the cancers it can cause often develop earlier in life than in the general population. There is no cure, but regular cancer screening and, in some cases, preventive surgery or medicines lower the risk. Most people who follow recommended care plans can expect a near-typical lifespan.
Is Lynch syndrome hereditary?
Yes. Lynch syndrome is passed down through families in an autosomal dominant pattern: if one parent carries a mutation in one of the Lynch syndrome genes, each biological child has a 50% chance of inheriting it. A family history of early or multiple Lynch-related cancers is often the first clue.
What causes Lynch syndrome?
Lynch syndrome is caused by an inherited mutation in one of five DNA-repair genes: MLH1, MSH2, MSH6, PMS2, or EPCAM. These mismatch repair genes normally correct small copying errors in DNA. When the healthy copy is later damaged or lost in a cell, errors build up and can cause cells to grow out of control and become cancer.
Does Lynch syndrome have symptoms?
Lynch syndrome itself usually causes no symptoms until a cancer develops. When symptoms appear, they come from the cancer: blood in the stool or bowel changes from colon cancer, unusual vaginal bleeding or pelvic pain from endometrial cancer, indigestion or unexplained anemia from stomach or small bowel cancer, or blood in the urine from urinary tract cancer. Regular screening is the most reliable way to catch cancer early.
How is Lynch syndrome diagnosed?
Diagnosis usually starts with a review of family cancer history. Cancer cell testing (IHC or MSI) may be done first, followed by genetic testing on a blood, saliva, or cheek swab sample. Only medical-grade genetic testing ordered through a healthcare professional or genetic counselor can confirm the diagnosis.
Can an at-home DNA test detect Lynch syndrome?
No. There are no reliable at-home testing kits for Lynch syndrome. At-home DNA tests usually check only a few common genetic markers and cannot do the detailed testing needed to find changes in the MLH1, MSH2, MSH6, PMS2, or EPCAM genes. Accurate results need a medical-grade test from a certified laboratory, ordered by a healthcare professional or genetic counselor.
What age should colonoscopy start with Lynch syndrome?
People with Lynch syndrome should begin colonoscopies at ages 20 to 25, or 2 to 5 years earlier than the youngest age at which a family member was diagnosed with colorectal cancer, and repeat them every 1 to 2 years. A colonoscopy cannot diagnose Lynch syndrome, but it can find and remove growths before they become cancer.
What cancers does Lynch syndrome cause?
Lynch syndrome raises the lifetime risk of colon, endometrial, uterine, and ovarian cancers most notably, plus cancers of the stomach, small bowel, urinary tract, pancreas, biliary system, brain, prostate, and sebaceous skin glands. Current research has not shown a clear link with breast cancer.
Is there a treatment or cure for Lynch syndrome?
There is no cure because Lynch syndrome is an inherited genetic condition. Management focuses on cancer screening, plus preventive options such as hysterectomy, oophorectomy, colectomy, an IUD or birth control pills, and in some cases daily aspirin to lower colorectal cancer risk.
What is the life expectancy for someone with Lynch syndrome?
Most people with Lynch syndrome who follow recommended care plans can expect a near-typical lifespan. Thanks to regular colonoscopies, endometrial screening, and preventive surgeries, cancers are more often found early or prevented altogether.
Trusted External Resources
Related Reading
Colonoscopy: Purpose, Prep, Procedure, Results and Risks: People with Lynch syndrome often need colonoscopy screening earlier and more often than the general population.
Learn more in our guide to Colorectal Cancer Screening: When to Start, Test Options and What Results Mean.
Genetic Testing for Cancer Risk: Who Needs It, How It Works and What Results Mean explains how inherited gene changes that raise cancer risk are tested.
References
Mayo Clinic. Lynch syndrome - Symptoms and causes. Mayo Clinic. December 2, 2025. https://www.mayoclinic.org/diseases-conditions/lynch-syndrome/symptoms-causes/syc-20374714
Mayo Clinic. Lynch syndrome - Diagnosis and treatment. Mayo Clinic. December 2, 2025. https://www.mayoclinic.org/diseases-conditions/lynch-syndrome/diagnosis-treatment/drc-20374719
Dominguez-Valentin M, Sampson JR, Seppälä TT, et al. Cancer risks by gene, age, and gender in 6350 carriers of pathogenic mismatch repair variants: findings from the Prospective Lynch Syndrome Database. Genet Med. 2020;22(1):15-25. PMID 31337882. https://doi.org/10.1038/s41436-019-0596-9
Burn J, Sheth H, Elliott F, et al. Cancer prevention with aspirin in hereditary colorectal cancer (Lynch syndrome), 10-year follow-up and registry-based 20-year data in the CAPP2 study: a double-blind, randomised, placebo-controlled trial. Lancet. 2020;395(10240):1855-1863. PMID 32534647. https://doi.org/10.1016/S0140-6736(20)30366-4
Järvinen HJ, Aarnio M, Mustonen H, et al. Controlled 15-year trial on screening for colorectal cancer in families with hereditary nonpolyposis colorectal cancer. Gastroenterology. 2000;118(5):829-834. PMID 10784581. https://doi.org/10.1016/s0016-5085(00)70168-5
Medical disclaimer
This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. The clinical information in this guide reflects source material last reviewed in December 2025.
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