Lynch Syndrome

About

Lynch syndrome runs in families in an autosomal dominant inheritance pattern. If more than one parent carries a gene mutation for Lynch syndrome, there is a 50 percent chance that the mutation will be passed on to each child.

In a few people, the genetic defect associated with Lynch syndrome arises spontaneously. Although people with a new mutation don't inherit it themselves, they can pass it on to their children.

Normally, the genes involved in Lynch syndrome — most commonly, MLH1, MSH2 and MSH6 — repair mismatches that occur during replication of DNA, the genetic material that contains instructions for every chemical process in your body. But defective genes cannot repair these minor mistakes. Over time, the accumulation of unrepaired errors leads to increasing genetic damage within cells and sometimes to cancer.

Yet unlike familial adenomatous polyposis, another hereditary colon disorder, cancer isn't inevitable in Lynch syndrome. Some people with the syndrome never develop colon polyps or cancer. For others, comprehensive screening and surveillance programs can help find cancerous changes in the earliest stages, when they are most easily treated.

Read more about Lynch syndrome at Mayoclinic.com.