© Copyright 2025 American Medical Association. All rights reserved.
The CPT® Code 81121 pertains to the analysis of the IDH2 gene, specifically focusing on common variants such as R140W and R172M, which are associated with glioma tumors. Gene analysis is a critical procedure that helps in identifying mutations in the isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) genes, both of which play significant roles in the development of gliomas, the most prevalent type of primary brain tumors. Gliomas originate from glial cells, which are supportive cells in the brain and spinal cord, and can be classified into various types, including astrocytomas, ependymomas, and oligodendrogliomas. The IDH1 gene is located on the long (q) arm of chromosome 2 at position 34, while the IDH2 gene is found on the long (q) arm of chromosome 15 at position 26.1. The IDH1 gene encodes the enzyme isocitrate dehydrogenase 1, which is primarily located in the cytoplasm and peroxisomes, whereas the IDH2 gene encodes isocitrate dehydrogenase 2, which is situated in the mitochondria. These enzymes are responsible for converting isocitrate to 2-ketoglutarate, a process that also generates NADPH, a molecule that protects cells from oxidative stress. Mutations in the IDH1 and IDH2 genes disrupt the normal function of these enzymes, leading to the abnormal production of D-2-hydroxyglutarate. This compound interferes with cell maturation and promotes the overproduction of immature cells, contributing to the formation of glioma tumors. The procedure for testing involves obtaining tumor tissue samples, which are then processed through DNA extraction and amplification using polymerase chain reaction (PCR) techniques. Specific primers targeting IDH1 codon 132 and IDH2 codon 172 are utilized, followed by pyrosequencing to analyze the presence or absence of these gene mutations. This analysis is essential for stratifying the prognosis of glioma tumors and guiding treatment decisions.
© Copyright 2025 Coding Ahead. All rights reserved.
The IDH2 gene analysis (CPT® Code 81121) is indicated for the evaluation of glioma tumors, particularly in the context of identifying common variant mutations associated with these tumors. The following conditions and scenarios warrant the performance of this genetic test:
The procedure for conducting the IDH2 gene analysis involves several critical steps to ensure accurate results. First, tumor tissue samples are obtained from the patient, which is a necessary prerequisite for the analysis. This sample collection is performed through a separately reportable procedure, ensuring that the tissue is suitable for genetic testing. Once the tumor tissue is acquired, DNA is extracted from the tumor cells. This extraction process is crucial as it isolates the genetic material needed for further analysis.
Following DNA extraction, the next step involves amplifying the extracted DNA using polymerase chain reaction (PCR). This technique employs specific primers that target IDH1 codon 132 and IDH2 codon 172, allowing for the selective amplification of the regions of interest within the genes. The PCR process is essential for generating sufficient quantities of DNA to facilitate accurate testing.
After amplification, the DNA sample undergoes pyrosequencing, a method that enables the detailed analysis of the genetic material. This sequencing technique is employed to detect the presence or absence of mutations in the IDH2 gene, specifically the common variants associated with glioma tumors. The results of this analysis provide valuable information regarding the genetic profile of the tumor, which can be instrumental in guiding clinical decisions and treatment planning.
Post-procedure care following the IDH2 gene analysis primarily involves monitoring the patient for any potential complications related to the tissue sampling procedure. Additionally, once the results of the genetic analysis are available, healthcare providers will discuss the findings with the patient. This discussion may include the implications of the identified mutations, potential treatment options, and the overall prognosis based on the genetic profile of the glioma tumor. It is essential for patients to have a clear understanding of their results and how these may influence their treatment journey.
| Short Descr | IDH2 COMMON VARIANTS | Medium Descr | IDH2 COMMON VARIANTS | Long Descr | IDH2 (isocitrate dehydrogenase 2 [NADP+], mitochondrial) (eg, glioma), common variants (eg, R140W, R172M) | 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) | none | MUE | 1 |
| 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. | 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. | 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. | GA | Waiver of liability statement issued as required by payer policy, individual case | 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 | GZ | Item or service expected to be denied as not reasonable and necessary |
|
Date
|
Action
|
Notes
|
|---|---|---|
| 2018-01-01 | Added | Code Added. |
Get instant expert-level medical coding assistance.