How To Use CPT Code 81121

CPT 81121 describes the genetic analysis procedure for detecting common variants in the IDH2 gene, specifically related to mitochondrial isocitrate dehydrogenase 2. This article will cover the description, procedure, qualifying circumstances, appropriate usage, documentation requirements, billing guidelines, historical information, similar codes and billing examples.

1. What is CPT Code 81121?

CPT 81121 can be used to describe the genetic analysis procedure performed to detect common variants in the IDH2 gene, specifically related to mitochondrial isocitrate dehydrogenase 2. This code is used when the lab analyst performs the technical steps involved in extracting nucleic acids, amplifying the gene, and detecting the target genes using a specimen source such as formalin-fixed paraffin-embedded tissue.

2. Official Description

The official description of CPT code 81121 is: ‘IDH2 (isocitrate dehydrogenase 2 [NADP+], mitochondrial) (eg, glioma), common variants (eg, R140W, R172M).’

3. Procedure

1. The lab analyst performs the technical steps involved in the genetic analysis procedure for detecting common variants in the IDH2 gene.
2. This includes extracting nucleic acids, amplifying the gene, and detecting the target genes using a specimen source such as formalin-fixed paraffin-embedded tissue.
3. The procedure may also involve additional steps such as digestion, cell lysis, and increasing and stabilizing the quantity of nucleic acid for analysis.
4. The lab analyst uses methods such as nucleic acid probes to detect the presence of common variants in the IDH2 gene.
5. The procedure may be ordered by clinicians for individuals with glioma, a type of primary brain tumor, to determine the presence of IDH2 mutations and their potential clinical implications for treatment.

4. Qualifying circumstances

CPT 81121 is used for individuals undergoing genetic analysis to detect common variants in the IDH2 gene. This procedure is not limited to a specific condition but may be ordered for individuals with glioma. The presence of IDH2 mutations, along with common IDH1 mutations, may indicate a lower-grade glioma with improved prognostic outlook and may have possible clinical implications for treatment.

5. When to use CPT code 81121

CPT code 81121 should be used when performing the genetic analysis procedure to detect common variants in the IDH2 gene. It is appropriate to bill this code when the lab analyst performs the technical steps involved in the procedure, including nucleic acid extraction, gene amplification, and target gene detection. This code should be used for each individual undergoing the genetic analysis procedure.

6. Documentation requirements

To support a claim for CPT 81121, the documentation should include:

• Indication for the genetic analysis procedure and the reason for ordering it
• Details of the technical steps performed, including nucleic acid extraction, gene amplification, and target gene detection
• Specimen source used for the analysis, such as formalin-fixed paraffin-embedded tissue
• Results of the analysis, including the presence or absence of common variants in the IDH2 gene
• Signature of the lab analyst performing the procedure

7. Billing guidelines

When billing for CPT 81121, ensure that the procedure is performed by a lab analyst and includes the necessary technical steps for genetic analysis. It is important to distinguish CPT 81121 for IDH2 common variants from CPT 81120 for IDH1 common variants. Additional prep work, such as tissue selection or microdissection, may be separately reported if documented. If the pathologist provides an interpretation and writes a report, you may additionally report G0452 with modifier 26 to Medicare and other payers, as long as an MD or DO physician performs the interpretation.

8. Historical information

CPT 81121 was added to the Current Procedural Terminology system on January 1, 2018. There have been no updates to the code since its addition.

9. Examples

1. A lab analyst performing the genetic analysis procedure to detect common variants in the IDH2 gene for an individual with glioma.
2. A geneticist conducting the technical steps involved in the analysis of IDH2 common variants for a patient with suspected genetic disorders.
3. A pathologist interpreting the results of the genetic analysis procedure for an individual with glioma to determine the presence of IDH2 mutations.
4. A molecular biologist performing the necessary steps for gene amplification and target gene detection in the IDH2 gene for research purposes.
5. A lab technician extracting nucleic acids and preparing the specimen for the genetic analysis of IDH2 common variants in a patient with suspected mitochondrial disorders.
6. A genetic counselor explaining the implications of IDH2 common variants to a patient with glioma and their potential impact on treatment decisions.
7. A research scientist analyzing the presence of IDH2 mutations in a large cohort of glioma patients to study their association with prognosis.
8. A lab analyst performing the genetic analysis procedure to detect common variants in the IDH2 gene for a patient enrolled in a clinical trial for targeted therapies.
9. A pathologist reviewing the results of the genetic analysis procedure for an individual with glioma and providing a comprehensive report to the treating physician.
10. A geneticist conducting quality control measures during the genetic analysis procedure to ensure accurate and reliable results for patients with suspected IDH2 mutations.