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Molecular genetic testing is a critical procedure used to identify specific mutations in the NRAS (neuroblastoma RAS viral [v-ras] oncogene homolog) gene, particularly focusing on variants located in exon 2 (codons 12 and 13) and exon 3 (codon 61). This gene is situated on chromosome 1 and plays a significant role in the development of colorectal cancers. The NRAS gene encodes a membrane-bound protein that possesses GTPase activity, which is essential for regulating cell signaling pathways. Mutations in the specified regions of the NRAS gene can disrupt the intrinsic pathway responsible for RAS-GAP mediated GTP hydrolysis, leading to aberrant activation of the epidermal growth factor receptor (EGFR) signaling cascade. This disruption is crucial as it contributes to the processes of malignant cell proliferation, invasion, metastasis, and neovascularization. The identification of these mutations through genetic testing is particularly important for individuals diagnosed with colorectal carcinoma, as it aids in evaluating the potential effectiveness of targeted monoclonal antibody therapies, such as cetuximab and panitumumab. These therapies work by binding to the EGFR, thereby inhibiting the downstream signaling pathways that promote tumor growth and spread.
© Copyright 2025 Coding Ahead. All rights reserved.
The molecular genetic testing for NRAS gene analysis is indicated for patients diagnosed with colorectal carcinoma. This testing is essential for identifying specific mutations that may influence treatment decisions, particularly regarding the use of monoclonal antibody therapies. The following conditions warrant the performance of this genetic test:
The procedure for NRAS gene analysis involves several key steps to ensure accurate identification of mutations in the specified exons. The following procedural steps are typically followed:
After the NRAS gene analysis is completed, the results are typically available within a specified timeframe, depending on the laboratory's processing capabilities. Healthcare providers will review the results to determine the presence of any NRAS mutations. If mutations are identified, this information is critical for guiding treatment options, particularly regarding the use of targeted therapies such as cetuximab and panitumumab. Patients may require follow-up consultations to discuss the implications of the test results and to plan appropriate treatment strategies. Additionally, it is important for healthcare providers to document the findings in the patient's medical record for ongoing management and care.
| Short Descr | NRAS GENE VARIANTS EXON 2&3 | Medium Descr | NRAS GENE ANALYSIS VARIANTS IN EXON 2&3 | Long Descr | NRAS (neuroblastoma RAS viral [v-ras] oncogene homolog) (eg, colorectal carcinoma), gene analysis, variants in exon 2 (eg, codons 12 and 13) and exon 3 (eg, codon 61) | 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 |
| 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. | XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service | XS | Separate structure, a service that is distinct because it was performed on a separate organ/structure | GW | Service not related to the hospice patient's terminal condition | 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. | 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. | GC | This service has been performed in part by a resident under the direction of a teaching physician | GV | Attending physician not employed or paid under arrangement by the patient's hospice provider |
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| 2016-01-01 | Added | Added |
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