Overview

• Purpose: MSH6 testing is often used to assess genetic risk for hereditary cancer syndromes, such as Lynch syndrome (also known as hereditary nonpolyposis colorectal cancer, or HNPCC). Lynch syndrome increases the risk of several types of cancer, including colorectal, endometrial, ovarian, and others.
• Testing: This involves analyzing a sample to identify mutations in the MSH6 gene. Identifying mutations can help determine a person's risk of developing cancers associated with Lynch syndrome.

Risk Assessment

• Normal Range: For MSH6 testing, the "normal" result means no mutations are detected in the MSH6 gene. This would suggest that the individual does not have the MSH6 mutation that is associated with an increased risk for Lynch syndrome-related cancers.
• Abnormal Range: A detected mutation indicates that there is a genetic variant in the MSH6 gene. This could mean an increased risk for Lynch syndrome-related cancers. The specific risk level can vary depending on the type and impact of the mutation found.

Normal Range for MSH6 Test:
1. Genetic Testing: If no pathogenic mutations are detected in the MSH6 gene, this is considered normal. The gene should not have alterations that affect its function.
   
2. Immunohistochemistry (IHC) Test: In some cases, the expression of the MSH6 protein is tested in tumor samples. A normal result would indicate that MSH6 protein is present in the cells at normal levels.

3. Microsatellite Instability (MSI) Testing: This test looks at the stability of microsatellite regions in the DNA. A normal result would show no microsatellite instability, meaning the MSH6 gene is functioning properly in DNA repair.

Interpretation

• Positive Result: A positive result (detection of a mutation) suggests that the individual carries a mutation in the MSH6 gene. This is associated with an increased risk of developing cancers related to Lynch syndrome. Further evaluation by a genetic counselor or specialist is usually recommended to understand the implications for personal health and for family members.
• Negative Result: A negative result (no mutation detected) suggests that no known pathogenic mutations in the MSH6 gene are present. However, it's important to note that a negative result does not entirely rule out the possibility of having an increased cancer risk, as there are other genetic and environmental factors that can contribute.

Sample Type

• Sample Type: The test typically uses a blood sample, but other types of samples, such as saliva or tissue biopsies, may be used depending on the laboratory and the specific test being conducted.