Lynch syndrome is an inherited condition that increases the risk of colon cancer and other cancers. Lynch syndrome was previously known as hereditary nonpolyposis colorectal cancer (HNPCC).

Lynch syndrome is the most common disorder that increases the risk of colon cancer. It also causes for colon cancer to occur at an earlier age than it might in the general population.



Symptoms of Lynch syndrome may include:

  • Colon cancer that occurs before the age of 50
  • Family history of colon cancer that occurs at a young age
  • Family history of cancer that affects the uterus (endometrial cancer)
  • Family history of other related cancers such as ovarian cancer, kidney cancer, stomach cancer, small intestine cancer, liver cancer, sweat gland cancer and other cancers.



Lynch syndrome occurs in families in an autosomal dominant inheritance pattern. This means that if one parent carries the gene mutation for Lynch syndrome there is a 50% chance the mutation will be passed on to the children.


How gene mutations cause cancer


The genes inherited in Lynch syndrome are normally responsible for correcting mistakes in the genetic code (mismatch repair genes).

Normal cells have mechanisms to recognize mistakes and repair them. However, people who inherit abnormal genes associated with Lynch syndrome lack the ability to repair the mistakes. An accumulation of mistakes leads to increasing genetic damage within cells that can cause for the cells to become cancerous.



Beyond health complications, a genetic disorder such as Lynch syndrome can cause other concerns related to:

  • Personal privacy: Results of genetic tests are listed in medical records, which may be accessed by insurance companies and employers.
  • Children: If one parent is the carrier of the genetic mutation for Lynch syndrome, each child has a 50% chance of inheriting the mutation.
  • Extended family: A diagnosis for Lynch syndrome can impact the entire family.



The following tips can help prevent cancers associated with Lynch syndrome:

  • Frequent cancer screening
  • Preventive surgery
  • Aspirin
  • Healthy diet rich in fruits and vegetables
  • Regular exercise
  • Maintaining a healthy weight
  • Quitting smoking