Lynch Syndrome
Description
Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer (HNPCC), is an inherited disorder that increases the risk of developing certain types of cancer. This condition is caused by mutations in specific genes involved in DNA mismatch repair, a process that corrects errors during DNA replication. Individuals with Lynch syndrome have a significantly elevated risk of colorectal cancer, as well as other cancers such as endometrial, stomach, ovarian, small bowel, urinary tract, and pancreatic cancers.
Genes Involved
The following genes are commonly associated with Lynch syndrome:
- MLH1
- MSH2
- MSH6
- PMS2
- EPCAM
Mutations in these genes disrupt the DNA mismatch repair process, leading to an increased risk of cancer development.
Recognizing the Signs and Symptoms
Lynch syndrome often presents with no noticeable symptoms in the early stages. However, as the condition progresses, individuals may experience various signs and symptoms, including:
- Colorectal cancer: Blood in the stool, changes in bowel habits, abdominal pain, unexplained weight loss, fatigue.
- Endometrial cancer: Abnormal vaginal bleeding, pelvic pain, abnormal vaginal discharge.
- Other cancers: Depending on the specific genes involved, individuals may also experience symptoms related to other cancers, such as stomach pain, nausea, vomiting, frequent urination, or back pain.
Causes
Lynch syndrome is caused by inherited mutations in genes responsible for DNA mismatch repair. These mutations are passed down from a parent to their child, meaning that individuals with Lynch syndrome have a 50% chance of passing the mutation to their offspring.
Inheritance/recurrence risk
Lynch syndrome is an autosomal dominant condition, meaning that a single copy of the mutated gene is sufficient to cause the disorder. Individuals with Lynch syndrome have a 50% chance of passing the mutation to their children, increasing their risk of developing cancer. Family history of cancer, especially at a younger age, is a key indicator of Lynch syndrome.
