What is Lynch syndrome?
Sining Chen: Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer, is characterized by the inheritance of genetic defects in the MLH1, MSH2 and MSH6 genes. Lynch syndrome predisposes families to developing colorectal cancer and endometrial cancer in women. Colorectal cancer due to Lynch syndrome also develops at younger ages than would be expected in people without the genetic defects. Lynch syndrome accounts for about 2 percent of all colorectal cancer diagnoses and a large fraction of early onset colorectal cancers. It is the most common familial colorectal cancer syndrome. Q: What genetic defects are involved? SC: The genes we are concerned with in Lynch syndrome are called “mismatch repair genes.” These genes repair mismatches that occur during the duplication of the genetic code when new cells are made. When there is a defect in these genes, mismatches may not be repaired properly and cancer cells may arise. Such defects can be passed from generation to generati
