Lynch syndrome

Changes in the MLH1, MSH2, MSH6 and PMS2 genes

The MLH1, MSH2, MSH6 and PMS2 genes are "mismatch repair” genes that help cells repair mistakes in your DNA. When one of these genes isn’t working properly, errors can add up in the DNA of cells in different parts of the body, which can increase your risk for certain cancers.

Lynch syndrome and your cancer risk

Colon, uterine and ovarian cancers are the main cancer risks that increase with Lynch syndrome. Other elevated cancer risks include pancreatic, stomach, brain, small bowel, bladder, biliary and urinary tract cancer and skin tumors. 

The risk for these cancers depends on several factors, including which gene is affected and your family history. However, people with changes in the Lynch syndrome genes may never develop cancer. With appropriate screening and management, many of these cancers can be prevented or detected at an early, treatable stage. 

If you have a change in a gene associated with Lynch syndrome, talk with a genetic counselor and your doctor to learn more about your risks. They can help you develop an action plan that’s right for you.

Living with Lynch syndrome

If you've been found to have a genetic change associated with Lynch syndrome, the following proactive steps are key to minimizing your cancer risk:

• Talking with a genetic counselor and your doctors about how to manage your cancer risks
• Routine cancer screenings, including frequent colonoscopies and upper endoscopies starting in young adulthood
• Adopting healthy habits, such as maintaining a healthy weight, exercising regularly and minimizing alcohol consumption
• Considering additional risk-reducing options, such as surgery to remove the uterus and ovaries

Recommendations can also change over time, so connect with your genetic counselor and doctors regularly.

What does Lynch syndrome mean for my family?

If you have a change in MLH1, MSH2, MSH6 or PMS2, we encourage you to share this information with your close blood relatives, as they may have Lynch syndrome, too.

Your close blood relatives (children, full siblings and parents) have a 50 percent chance of having the same genetic change. More distant relatives may also be at risk. At-risk family members can learn if they have the same genetic risk by getting a genetic test. A genetic counselor or provider with genetics expertise can arrange for testing.

Lynch syndrome resources

• AliveAndKickn: A Lynch syndrome hereditary cancer advocacy organization.
• Lynch Syndrome International: A patient-centered organization that supports research, advocacy and education about Lynch syndrome.

Find a provider with knowledge about Lynch syndrome

If you have a change in MLH1, MSH2, MSH6 or PMS2, talk with a genetic counselor and your primary care provider. Geisinger also has providers who specialize in helping people with Lynch syndrome develop a screening and management plan. They may also refer you to Geisinger's Inherited Risk Gastrointestinal Clinic.