CPT® Code 81319

PMS2 (postmeiotic segregation increased 2 [S. cerevisiae]) (eg, hereditary non-polyposis colorectal cancer, Lynch syndrome) gene analysis; duplication/deletion variants

The CPT® Code 81319 pertains to the molecular genetic testing of the PMS2 gene, specifically focusing on the identification of duplication or deletion variants. The PMS2 gene is crucial for the proper functioning of DNA repair mechanisms, and mutations in this gene can significantly increase an individual's risk of developing hereditary non-polyposis colorectal cancer (HNPCC), commonly referred to as Lynch syndrome. This genetic condition is characterized by a predisposition to colorectal cancer and other types of cancer, including endometrial and ovarian cancers. The PMS2 gene is located on chromosome 7 and encodes a protein that plays a vital role in the DNA mismatch repair system. When mutations occur, they can lead to the production of an abnormally short or nonfunctional PMS2 protein, which compromises the cell's ability to repair DNA errors. Over time, these unrepaired errors can accumulate, resulting in uncontrolled cell proliferation and tumor formation. In some cases, individuals may develop HNPCC due to a de novo mutation, meaning the mutation arises spontaneously in the germ cell or fertilized egg rather than being inherited from a parent. The testing associated with CPT® Code 81319 is essential for identifying specific genetic alterations that may inform risk assessment and management strategies for affected individuals and their families.