How To Use CPT Code 81243

CPT 81243 describes the analysis of the FMR1 gene to detect abnormal alleles, specifically those involving expanded sequences. 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 81243?

CPT 81243 is used to analyze the FMR1 gene for the presence of abnormal alleles, particularly those with expanded sequences. This test is typically performed to detect changes in the gene associated with Fragile X syndrome, a leading cause of inherited mental retardation. It can also help evaluate carrier status in females and identify other conditions such as primary ovarian insufficiency, late-onset ataxia, or tremor.

2. Official Description

The official description of CPT code 81243 is: ‘FMR1 (fragile X mental retardation 1) (eg, fragile X mental retardation) gene analysis; evaluation to detect abnormal (eg, expanded) alleles.’

3. Procedure

1. The lab analyst performs technical steps to analyze the FMR1 gene, including extracting nucleic acids, amplifying the gene for study, and detecting target genes using nucleic acid probes.

4. Qualifying circumstances

CPT 81243 is used when evaluating the FMR1 gene for abnormal alleles, specifically those with expanded sequences. This test is commonly ordered to assess carrier status in females and detect changes associated with Fragile X syndrome and other related conditions. It is important to note that this code is specifically for analyzing the FMR1 gene and does not include characterization of alleles.

5. When to use CPT code 81243

CPT code 81243 should be used when the lab performs the FMR1 gene analysis to detect abnormal alleles with expanded sequences. It is important to use this code when only one assay, typically polymerase chain reaction (PCR), is used for the analysis. If the assay includes characterization of alleles, CPT code 81244 should not be reported in addition to 81243.

6. Documentation requirements

To support a claim for CPT 81243, documentation should include:

• Indication for the test and the reason for performing the analysis
• Details of the technical steps performed, including nucleic acid extraction, amplification, and detection methods
• Results of the analysis, specifically identifying any abnormal alleles detected
• Signature of the lab analyst performing the analysis

7. Billing guidelines

When billing for CPT 81243, ensure that the analysis of the FMR1 gene is performed using a single assay, typically PCR. Do not report CPT 81244 if the assay includes characterization of alleles. If the ordering clinician requests physician interpretation of the test and the pathologist provides an interpretation and report, CPT code G0452 with modifier 26 may be additionally reported. It is important to note that the interpretation must be performed by an MD or DO physician, not a PhD laboratory scientist.

8. Historical information

CPT 81243 was added to the Current Procedural Terminology system on January 1, 2012. There have been no updates to the code since its addition.

9. Examples

1. A lab analyst performing the analysis of the FMR1 gene to detect abnormal alleles associated with Fragile X syndrome.
2. An obstetrician ordering the FMR1 gene analysis to evaluate carrier status in a pregnant woman.
3. A neurologist requesting the FMR1 gene analysis to assess a patient with late-onset ataxia.
4. A genetic counselor recommending the FMR1 gene analysis to a couple considering pregnancy.
5. A pediatrician ordering the FMR1 gene analysis to evaluate a child with developmental delays.
6. A reproductive endocrinologist requesting the FMR1 gene analysis to assess primary ovarian insufficiency in a patient.
7. A neurologist ordering the FMR1 gene analysis to evaluate a patient with tremor.
8. A geneticist recommending the FMR1 gene analysis to a family with a history of Fragile X syndrome.
9. An internist ordering the FMR1 gene analysis to assess a patient with unexplained intellectual disability.
10. A gynecologist requesting the FMR1 gene analysis to evaluate a patient with premature ovarian failure.