CPT® Code 81265

Comparative analysis using Short Tandem Repeat (STR) markers; patient and comparative specimen (eg, pre-transplant recipient and donor germline testing, post-transplant non-hematopoietic recipient germline [eg, buccal swab or other germline tissue sample] and donor testing, twin zygosity testing, or maternal cell contamination of fetal cells)

Molecular genetic testing, specifically through the use of Comparative analysis with Short Tandem Repeat (STR) markers, is a sophisticated procedure aimed at identifying genetic similarities between two individuals. This testing is particularly significant in various medical contexts, such as pre-transplant evaluations, where it is crucial to ensure compatibility between a donor and a recipient. STR markers are defined as sequences of DNA that consist of two or more nucleotides that repeat in tandem, and these markers are predominantly located in the non-coding regions of genes, known as introns. The analysis of these markers allows for the documentation of engraftment post-transplant and the detection of any residual disease that may persist in the recipient. Additionally, this testing is utilized in twin studies to determine zygosity, which refers to whether twins are identical (monozygotic) or fraternal (dizygotic). By comparing STR markers found in buccal mucosa samples, healthcare professionals can assess the genetic relationship between twins. Furthermore, in prenatal testing scenarios, STR markers are examined in fetal cells obtained through procedures like amniocentesis or chorionic villus sampling. These fetal samples are compared to maternal blood samples to rule out the possibility of maternal cell contamination, ensuring the accuracy of fetal genetic assessments. The CPT® Code 81265 is designated for reporting this comprehensive testing of a patient and comparative specimen, encompassing various applications such as pre-transplant donor-recipient testing, post-transplant evaluations, twin zygosity assessments, and maternal cell contamination analyses.