CPT® Code 81165

Molecular genetic testing is a critical procedure used to identify mutations in the BRCA1 gene, which is located on chromosome 17. This gene plays a vital role in stabilizing genetic material and preventing uncontrolled cell growth, functioning as a tumor suppressor. The BRCA1 gene is part of a gene family that is associated with the error-free repair of chromosomal damage and the repair of DNA double strand breaks. When mutations occur in the BRCA1 gene, the gene's ability to repair damaged DNA is compromised, leading to uncontrolled cell proliferation. Such mutations are significantly linked to an increased risk of developing early onset breast and ovarian cancers in females, as well as certain other cancers in both men and women. In females, BRCA1 mutations also elevate the risk of cervical, uterine, pancreatic, and colon cancers. In males, these mutations increase the risk of breast cancer, as well as pancreatic and testicular cancers. Genetic testing for BRCA1 mutations is essential as it can help identify hereditary cancer syndromes, guide appropriate treatment options, and inform family members who may be at risk. The testing process typically involves analyzing whole blood or buccal cells. The full sequence analysis, denoted by CPT® Code 81165, involves comparing segments of the BRCA1 gene to identify similarities or differences, thereby elucidating relationships and potential mutations. This analysis includes studying active and post-translational modification sites, gene structures, the distribution of introns and exons, and regulatory elements. Genetic markers are identified through the detection of point mutations or single nucleotide polymorphisms. Additionally, variants that are not identified through sequence analysis may be detected using a full duplication/deletion analysis (CPT® Code 81166), which is designed to uncover large gene rearrangements. In a normal genetic context, there should be two copies of the BRCA1 gene per cell, except in the case of sex chromosomes; thus, the presence of zero or one copy indicates a deletion variant, while three or more copies suggest a duplication variant. Furthermore, when testing for a known familial variant (CPT® Code 81215), a specific site on the BRCA1 gene is analyzed for mutations that have already been identified in another family member.