Summary & Overview
CPT 81344: TBP Gene Expanded Allele Detection, Molecular Test
CPT code 81344 represents a molecular laboratory test that detects expanded sequence alleles in the TATA box binding protein (TBP) gene. This diagnostic assay identifies abnormal allele expansions that can have clinical implications for inherited neurologic and neuromuscular conditions. Nationally, molecular genetic tests like CPT code 81344 are important for confirming diagnoses, informing genetic counseling, and guiding patient management.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context for TBP expansion testing, national relevance of molecular diagnostic billing, and typical places of service. The publication summarizes common billing modifiers and lists associated administrative elements where available. It also outlines what readers can expect in terms of benchmarks and policy-relevant issues for molecular diagnostic coding, including coverage considerations and coding clarity.
The report is intended for clinicians, billing professionals, and policy analysts who need a succinct reference for CPT code 81344, its clinical purpose, and the administrative considerations that affect laboratory genetic testing at a national level.
Billing Code Overview
CPT code 81344 describes a laboratory procedure that detects expanded sequence alleles in the TATA box binding protein (TBP) gene. The service involves a technical laboratory test performed by a lab analyst to identify abnormal allele expansions associated with TBP.
Service type: Molecular genetic testing / laboratory analytical service
Typical site of service: Clinical laboratory
Clinical & Coding Specifications
Clinical Context
A 42-year-old adult presents to a genetics clinic with progressive cerebellar ataxia, dysarthria, and a family history of adult-onset neurodegenerative disease. The neurologist orders molecular diagnostic testing to evaluate for repeat expansion disorders involving the TATA box binding protein (TBP) gene given clinical suspicion for spinocerebellar ataxia type 17 (SCA17). A peripheral blood sample is collected in the outpatient phlebotomy lab and sent to a molecular diagnostics laboratory. The laboratory analyst performs the technical assay described by 81344 to detect expanded TBP alleles using fragment analysis, repeat-primed PCR, or comparable methods. Results are reviewed in the laboratory information system, a technical report is generated, and the laboratory director or clinical geneticist issues the final interpretation to the ordering neurologist. Typical sites of service include outpatient hospital laboratories, independent reference molecular laboratories, and academic medical center genetics laboratories. Typical clinical workflow steps: specimen collection, specimen accessioning, DNA extraction, repeat expansion testing for TBP, result validation, and transmission of the final report to the ordering provider.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component |