CPT® Code 81296

MSH2 (mutS homolog 2, colon cancer, nonpolyposis type 1) (eg, hereditary non-polyposis colorectal cancer, Lynch syndrome) gene analysis; known familial variants

The CPT® Code 81296 pertains to the molecular genetic testing of the MSH2 gene, specifically focusing on known familial variants associated with hereditary non-polyposis colorectal cancer (HNPCC), also known as Lynch syndrome. This testing is crucial for identifying specific mutations within the MSH2 gene that significantly increase an individual's risk of developing colorectal cancer and other related malignancies. The MSH2 gene is located on chromosome 2 and plays a vital role in the DNA mismatch repair system. It forms part of a protein complex that detects and corrects errors that occur during DNA replication. When these errors are not repaired, they can accumulate, leading to uncontrolled cell growth and the formation of tumors. HNPCC is the most prevalent cancer syndrome linked to mutations in the MSH2 gene, but it is important to note that tumors can also arise in various other organs, including the endometrium, ovaries, prostate, stomach, small intestine, liver, gallbladder duct, upper urinary tract, brain, and skin. Lynch syndrome is identified in approximately 40 percent of individuals diagnosed with HNPCC, highlighting the significant hereditary risk associated with this condition. The testing process for CPT® Code 81296 is particularly relevant when a family member has already been identified with a mutation in the MSH2 gene. In such cases, molecular genetic testing is recommended for other family members to determine if they carry the same mutation. Those who test positive for the familial variant should receive genetic counseling and may be offered clinical supervision to monitor their health proactively. This testing is distinct from other codes such as 81295, which involves full sequence analysis of the gene, and 81297, which focuses on deletion or duplication variants of the MSH2 gene.