CPT® Code 81265

Official Description

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)

Common Language Description

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.

1. Indications

The comparative analysis using Short Tandem Repeat (STR) markers is indicated for several specific scenarios, including:

Pre-Transplant Recipient and Donor Testing This testing is performed to ensure compatibility between a transplant recipient and their donor by analyzing genetic markers.
Post-Transplant Non-Hematopoietic Recipient Germline Testing After a transplant, this analysis helps in monitoring the recipient's genetic makeup to detect any residual disease.
Twin Zygosity Testing This is utilized to determine whether twins are identical or fraternal by comparing their genetic markers.
Maternal Cell Contamination of Fetal Cells This testing is crucial during prenatal assessments to confirm that fetal samples are not contaminated with maternal cells, ensuring accurate genetic analysis.

2. Procedure

The procedure for conducting a comparative analysis using Short Tandem Repeat (STR) markers involves several key steps:

Sample Collection The first step involves collecting DNA samples from both the patient and the comparative specimen. This may include obtaining a buccal swab or other germline tissue samples from the donor and recipient in pre-transplant scenarios, or fetal cells from amniocentesis or chorionic villus sampling.
DNA Extraction Once the samples are collected, DNA is extracted from both the patient and comparative specimens. This process involves breaking down the cellular structure to isolate the DNA for analysis.
STR Marker Analysis The extracted DNA is then analyzed for specific STR markers. This involves using techniques such as polymerase chain reaction (PCR) to amplify the STR regions, allowing for detailed examination of the repeating sequences.
Comparison of Results The STR markers from the patient and the comparative specimen are compared to assess genetic similarities or differences. This comparison is critical for determining compatibility in transplant scenarios, zygosity in twins, or contamination in prenatal testing.
Documentation and Reporting Finally, the results of the analysis are documented, and the findings are reported. This includes detailing the presence or absence of specific STR markers and their implications for the clinical scenario being addressed.

3. Post-Procedure

After the comparative analysis using STR markers is completed, several considerations are important for post-procedure care and follow-up. The results should be reviewed in the context of the clinical scenario, whether it be for transplant compatibility, twin zygosity determination, or prenatal assessments. In cases of pre-transplant testing, the healthcare provider will discuss the findings with the patient and determine the next steps in the transplant process. For prenatal testing, if maternal cell contamination is ruled out, further genetic counseling may be provided based on the fetal genetic results. It is essential to ensure that all documentation is complete and that the results are communicated effectively to all relevant healthcare professionals involved in the patient's care.

Short Descr	STR MARKERS SPECIMEN ANAL
Medium Descr	COMPARATIVE ANAL STR MARKERS PATIENT&COMP SPEC
Long Descr	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)
Status Code	Statutory Exclusion (from MPFS, may be paid under other methodologies)
Global Days	XXX - Global Concept Does Not Apply
PC/TC Indicator (26, TC)	9 - Not Applicable
Multiple Procedures (51)	9 - Concept does not apply.
Bilateral Surgery (50)	9 - Concept does not apply.
Physician Supervisions	09 - Concept does not apply.
Assistant Surgeon (80, 82)	9 - Concept does not apply.
Co-Surgeons (62)	9 - Concept does not apply.
Team Surgery (66)	9 - Concept does not apply.
Diagnostic Imaging Family	99 - Concept Does Not Apply
CLIA Waived (QW)	No
APC Status Indicator	Service Paid under Fee Schedule or Payment System other than OPPS
Type of Service (TOS)	5 - Diagnostic Laboratory
Berenson-Eggers TOS (BETOS)	T1H - Lab tests - other (non-Medicare fee schedule)
MUE	1
CCS Clinical Classification	234 - Pathology

This is a primary code that can be used with these additional add-on codes.

81266

Addon Code Resequenced Code MPFS Status: Statutory exclusion (from MPFS, may be paid under other methodologies) APC A Comparative analysis using Short Tandem Repeat (STR) markers; each additional specimen (eg, additional cord blood donor, additional fetal samples from different cultures, or additional zygosity in multiple birth pregnancies) (List separately in addition to code for primary procedure)

26	Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number.
59	Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
90	Reference (outside) laboratory: when laboratory procedures are performed by a party other than the treating or reporting physician or other qualified health care professional, the procedure may be identified by adding modifier 90 to the usual procedure number.
GY	Item or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit
XU	Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service