Peutz-Jeghers Syndrome (PJS) is a genetic condition which can increase the risk of colon and other cancers. Proper medical care and early cancer screening will help people with PJS best manage their increased cancer risk.
Peutz-Jeghers Syndrome, Genetics, and Familial Colon Cancers
About 75% of colon cancers are considered sporadic cases and have no known genetic cause or family history. Among the remaining colon cancers, one possible genetic cause is called Peutz-Jeghers Syndrome (PJS).
PJS is fairly rare and only occurs in an estimated 1 in 25,000 to 1 in 300,000 people born in the US. People with Peutz-Jeghers syndrome are prone to developing many polyps in the stomach and intestines, beginning in childhood or the teen years. This can lead to medical problems such recurrent bowel obstructions.
Along with an increased risk of colon cancer, people with PJS have an increased risk of cancers of the stomach, small intestine, pancreas, cervix, breast and ovaries. However, as a cause of colon cancer, PJS is quite rare.
How is PJS Inherited?
Most cases of PJS occurs when a damaged form of a gene, referred to as STK11, is passed from parents to children. Genes are the instruction manual for building and running the human body. Nearly every cell in our bodies contains two copies of each gene. One copy comes from your mother and one copy comes from your father. In this way, if a mother or a father has changes in one or both copies of their STK11 gene, they may pass these changes onto their children, when they pass along their genes, resulting in the child having PJS.
For some diseases, if one of the two gene copies is damaged or missing, the other, good copy, will function normally and there will be no disease or increased risk of disease. This is called an autosomal recessive pattern.
For other diseases, including PJS, if even one copy of a pair of genes is damaged or missing, this is enough to increase disease risk or cause disease. This is called an autosomal dominant pattern.
Your Best Defense
If you find out that you have PJS, talk to your doctor about getting a referral to see a genetic counselor. Your doctor can help you find a qualified genetic counselor in your area or you can search the National Society of Genetic Counselors website to locate genetic counseling resources.
Seeing a genetic counselor is important because there are different changes to the STK11 gene that cause PJS. The changes that are present in your genes will determine your risk for developing colon or other cancers and medical complications. For example, the specific STK11 gene changes can determine whether you are likely to develop cancer early, such as in your 20s or later in life.
It is important to know your own personal risk so you can develop a plan to manage it. For example, if you have a form of PJS that greatly increases the odds of developing cancer early in life, it is important that you talk to your doctor about a cancer screening plan.
For many cancer types, including colon cancer, easily accessible screening tests are available. And even for cancer types that don't have a designated screening test, tools such as CT scans and MRI tests can be used to find cancer at its earliest stages, when it's most curable.
If you have PJS, you will likely need to be screened starting at a younger age and more frequently than people without PJS. While this may seem like a very serious inconvenience, it is one of the best ways to manage your increased risk of cancer.
The second important step you can take is to talk to your doctor about any other health risks that may be associated with having PJS. You can work together to develop a plan to best manage your health, taking into account the new information regarding your diagnosis of PJS.
American Society of Colon & Rectal Surgeons. Family History Registries. Accessed: March 16, 2009.
Gene Reviews: Peutz-Jeghers Syndrome. Accessed: March 16, 2009.
Genetic and Rare Diseases Information Center. Accessed: March 16, 2009.
Genetics Home Reference. Peutz-Jeghers syndrome. Accessed: Mar 16, 2009.