What is Lynch Syndrome?

Lynch Syndrome is a hereditary condition, which means it is passed from parents to their children. If one parent has Lynch Syndrome, there is a one in two (50%) chance it is passed on to their child.

Lynch Syndrome is caused by a mutation (a genetic change) in one of five different genes. These genes are called:

• MLH1
• MSH2
• MSH6
• PMS2
• EPCAM

The first four of these genes are called mismatch repair (MMR) genes, and they normally work to protect the body against cancer, for example by repairing some forms of damage to DNA in your cells. But if you have Lynch Syndrome, a mutation in one of these genes means that it is unable to do its job properly, so damaged cells may build up in your tissues and cause cancer.

Having Lynch Syndrome doesn’t mean you will definitely get cancer, but it does significantly increase your risk. Those with Lynch Syndrome who do get cancer, often do so before the age of 50.²

Your risk depends partly on your age, gender, which of the five genes has the mutation and the type of cancers that have been diagnosed in your family history. More information on the types of cancer associated with Lynch Syndrome is below.

There are other modifiable risk factors (in other words, risk factors you can do something about) that can affect your cancer risk, including smoking, alcohol consumption, diet and lifestyle. While healthy living is not a cast-iron guarantee against cancer, particularly against cancer caused by genetics, it can still lower the risk of developing the disease.

Consuming a healthy and nutritious diet, being physically active, and limiting alcohol and tobacco use, may all help to reduce cancer risk.³