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The CPT® Code 81355 pertains to the molecular genetic testing of the VKORC1 gene, which is crucial for understanding an individual's response to warfarin, a commonly used anticoagulant. This gene encodes the vitamin K epoxide reductase complex, subunit 1, an enzyme that plays a vital role in the vitamin K cycle, which is essential for blood clotting. The testing specifically identifies common variants of the VKORC1 gene, such as -1639G>A and c.173+1000C>T. The variant -1639G>A is a single nucleotide polymorphism (SNP) located in the promoter region of the VKORC1 gene. This mutation can lead to a reduction in the functional copies of the VKORC1 protein, thereby limiting the enzyme's availability for the conversion of vitamin K 2,3-epoxide to its active form. Understanding these genetic variations is particularly important for patients undergoing long-term warfarin therapy, as they can significantly influence the metabolism of the drug. For instance, individuals with the -1639G>A variant may require lower doses of warfarin due to a slower metabolism and a longer half-life of the drug in their system. The presence of this mutation is notably prevalent in certain populations, with up to 90% of individuals in Asian populations and around 50% in Caucasian populations carrying the variant. Therefore, molecular genetic testing for VKORC1 is essential for tailoring warfarin dosing to ensure effective anticoagulation while minimizing the risk of adverse effects.
© Copyright 2025 Coding Ahead. All rights reserved.
The molecular genetic testing for VKORC1 (CPT® Code 81355) is indicated for individuals who are undergoing long-term treatment or prevention of thromboembolic events with warfarin. The testing is particularly relevant for patients who may have variations in their VKORC1 gene that could affect their response to warfarin therapy. Identifying these genetic variants is crucial for determining appropriate dosing to achieve therapeutic anticoagulation while minimizing the risk of bleeding complications.
The procedure for molecular genetic testing of the VKORC1 gene involves several key steps to ensure accurate identification of genetic variants. First, a sample is collected from the patient, typically through a blood draw or saliva sample, which contains the DNA necessary for analysis. Next, the laboratory performs DNA extraction to isolate the genetic material from the sample. Following extraction, polymerase chain reaction (PCR) techniques are employed to amplify specific regions of the VKORC1 gene, allowing for detailed examination of the genetic sequences. Once amplification is complete, sequencing or genotyping methods are utilized to identify the presence of common variants, such as -1639G>A and c.173+1000C>T. The results of the genetic analysis are then interpreted by qualified laboratory personnel, who will provide a report detailing the identified variants and their potential implications for warfarin dosing. This comprehensive approach ensures that healthcare providers receive accurate and actionable information to guide treatment decisions.
After the molecular genetic testing for VKORC1 is completed, the results are typically communicated to the healthcare provider who ordered the test. It is essential for the provider to review the findings in conjunction with the patient's clinical history and current warfarin therapy. Based on the identified genetic variants, the provider may need to adjust the warfarin dosage to achieve the desired therapeutic effect while minimizing the risk of adverse reactions. Patients may also be monitored more closely for any signs of bleeding or clotting complications, especially if significant dose adjustments are made. Additionally, healthcare providers may consider further genetic counseling for patients and their families to discuss the implications of the test results and the importance of adherence to the adjusted warfarin regimen.
| Short Descr | VKORC1 GENE | Medium Descr | VKORC1 GENE ANALYSIS COMMON VARIANT(S) | Long Descr | VKORC1 (vitamin K epoxide reductase complex, subunit 1) (eg, warfarin metabolism), gene analysis, common variant(s) (eg, -1639G>A, c.173+1000C>T) | 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 |
| 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. | XS | Separate structure, a service that is distinct because it was performed on a separate organ/structure | XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service | GW | Service not related to the hospice patient's terminal condition | 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. | 91 | Repeat clinical diagnostic laboratory test: in the course of treatment of the patient, it may be necessary to repeat the same laboratory test on the same day to obtain subsequent (multiple) test results. under these circumstances, the laboratory test performed can be identified by its usual procedure number and the addition of modifier 91. note: this modifier may not be used when tests are rerun to confirm initial results; due to testing problems with specimens or equipment; or for any other reason when a normal, one-time, reportable result is all that is required. this modifier may not be used when other code(s) describe a series of test results (eg, glucose tolerance tests, evocative/suppression testing). this modifier may only be used for laboratory test(s) performed more than once on the same day on the same patient. | GA | Waiver of liability statement issued as required by payer policy, individual case | GV | Attending physician not employed or paid under arrangement by the patient's hospice provider |
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| 2016-01-01 | Changed | Description Changed |
| 2012-01-01 | Added | Added |
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