2025 CPT code 81178
(Active) Effective Date: N/A Revision Date: N/A Laboratory - Molecular Pathology Procedures Pathology and Laboratory Procedures Feed
Analysis of the ATXN1 gene to detect abnormal alleles, specifically expanded sequences, often associated with spinocerebellar ataxia type 1 (SCA1).
Modifiers may be applicable; refer to current CPT guidelines for appropriate use (e.g., modifier 26 for professional interpretation, modifier 99 for multiple procedures).
Medical necessity is typically established based on the patient's clinical presentation, family history of SCA1, or the need to determine carrier status.Payers may require additional documentation supporting the clinical suspicion of SCA1 or the need for genetic counseling.
The clinical laboratory performs all technical aspects, from nucleic acid extraction and amplification to detection of the target gene. Physician interpretation of results may be separately reported using modifier 26 (if ordered and performed by a physician).
In simple words: This lab test checks for changes in the ATXN1 gene that can cause a type of inherited movement disorder called spinocerebellar ataxia type 1 (SCA1). The test involves making copies of the gene and looking for unusually long repeating sections within it. This helps doctors diagnose SCA1 and identify people who might pass on the gene.
This CPT code encompasses the complete analytical process for ATXN1 gene analysis, aimed at identifying abnormal alleles characterized by expanded CAG trinucleotide repeat sequences. The procedure includes nucleic acid extraction (e.g., cell lysis, digestion), amplification (e.g., polymerase chain reaction), and detection of the target gene.The test is qualitative and assesses for expanded alleles, which are typically indicative of increased CAG repeats exceeding the normal range. Although not limited to any specific condition, this test is often used to aid in the diagnosis of SCA1 and to determine carrier status.
Example 1: A patient presents with progressive ataxia, dysarthria, and nystagmus.The physician orders ATXN1 gene analysis (81178) to assess for SCA1., A family history of SCA1 prompts genetic testing for at-risk individuals. ATXN1 gene testing is ordered to determine carrier status in family members., A patient presents with symptoms suggestive of SCA1, but initial clinical evaluation is inconclusive.ATXN1 gene analysis is performed to confirm or refute the diagnosis.
Patient demographics, detailed clinical history including neurological examination findings, family history, and indication for testing.Lab report indicating the method used, the number of CAG repeats, and interpretation.
** Specimen collection (e.g., blood draw) may be billed separately using an appropriate CPT code.Some payers may require specific documentation regarding the methodology used for the genetic analysis.
- Payment Status: Active
- Modifier TC rule: Not applicable.
- Specialties:Neurology, Genetics, Clinical Laboratory
- Place of Service:Clinical Laboratory