Hereditary Nonpolyposis Colorectal Cancer (HNPCC): PMS2 (Known Mutation)

Casandra

Casandra Test Code LC62002Version 1 (DRAFT)

Performing Lab

Lab LabcorpLab Test ID 511776

Hereditary Nonpolyposis Colorectal Cancer (HNPCC): PMS2 (Known Mutation)

Clinical Use

Use

Identify who in a family harbors the familial mutation and is at high risk of the disease and who does not harbor the familial mutation and is not at increased risk of the disease. Family testing for known familial mutations can identify presymptomatic mutation carriers within affected families who are at high risk of developing the familial disease.

Special Instructions

The test requires documentation of the familial mutation by the ordering physician. It is important for the physician to obtain informed consent from the patient for genetic testing, using the provided consent form. Additionally, in the context of family testing where results for the first tested patient (index case) were not from a LabCorp facility, those results need to be submitted to facilitate testing of other family members.

Limitations

The test employs Sanger sequencing to analyze selected regions of the PMS2 coding sequence. It cannot detect variants in regions not covered by the analysis, such as deep intronic areas, and may not reliably identify changes in repetitive elements. It is not designed to identify somatic mutations and might not detect mosaic variants or genomic rearrangements like inversions or transposable element insertions. The test's reliability may be compromised by allele dropout and the presence of pseudogenes, particularly concerning PMS2CL, which could interfere with detecting deletions or duplications unique to the PMS2 gene.

Test Details