Summary & Overview
CPT 0216U: Ataxia Repeat Expansion and Sequence Analysis
CPT code 0216U is a Proprietary Laboratory Analyses (PLA) code that identifies the Genomic Unity® Ataxia Repeat Expansion and Sequence Analysis from Variantyx Inc., a targeted genetic test for diagnosing ataxia caused by tandem repeat expansions across 12 loci. PLA codes are specific to a single manufacturer's or laboratory's proprietary test, making 0216U important for billing and utilization tracking of a unique molecular diagnostic service. Nationally, such PLA codes matter for payers, labs, and clinicians seeking precise identification of specialized genetic tests and for tracking adoption of advanced diagnostics.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of what the code represents, the clinical context for use in suspected repeat-expansion ataxias, typical service settings, and the implications of a PLA designation. The publication covers benchmarks and payer coverage considerations where available, summarizes clinical utility and testing scope, and highlights administrative aspects relevant to billing and claim submission. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 0216U is a Proprietary Laboratory Analyses (PLA) code for the Genomic Unity® Ataxia Repeat Expansion and Sequence Analysis by Variantyx Inc. The test analyzes tandem repeat expansions and sequence variants across 12 specific loci to aid diagnosis of ataxia caused by repeat expansions.
Service Type: Genetic laboratory testing — targeted repeat expansion and sequence analysis
Typical Site of Service: Independent or hospital-based clinical molecular diagnostic laboratory; specimens collected in ambulatory clinics or hospitals and sent to the performing laboratory.
Clinical & Coding Specifications
Clinical Context
A patient in their 20s–60s presents to a neurology clinic with progressive gait instability, imbalance, dysarthria, and/or coordination difficulties. The neurologist documents a clinical suspicion for hereditary or sporadic ataxia and orders specialized genetic testing to evaluate tandem repeat expansions and sequence variants across multiple ataxia-associated loci. A blood specimen is collected in an outpatient phlebotomy suite or ambulatory clinic and sent to Variantyx Inc. for the Genomic Unity® Ataxia Repeat Expansion and Sequence Analysis reported under 0216U. Results are reviewed by the ordering neurologist or geneticist to confirm a diagnosis of repeat expansion–associated ataxia, guide genetic counseling, family testing, and management decisions. Typical site of service: outpatient neurology clinic, specialty genetic clinic, or independent clinical laboratory performing PLA testing.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional interpretation component separate from technical laboratory processing if payer allows split billing. |
TC | Technical component | Use when billing only the laboratory technical component (performing the test) separate from professional interpretation. |
QX | Ordering physician attests X modifier requirements for assistant at surgery — (CMS-implementations) | Rare for this service; include only if specific payer requires credential attestation modifiers for ordering/performing personnel. |
QY | Medical direction of two, three, or four qualified individuals | Not typically used for PLA but may be applied if centralized lab medical director directs multiple performing sites and payer requires QY. |
AS | Physician assistant, nurse practitioner, or clinical nurse specialist services as primary | Use when an advanced practice provider is the ordering clinician and payer requires identification of that provider role. |
52 | Reduced services | Use if the lab test performed was substantially reduced in scope from the full PLA (rare; document reason). |
53 | Discontinued procedure | Use if specimen processing began but testing was discontinued for documented clinical reasons. |
62 | Two surgeons — co-surgeons | Not typically applicable; included for completeness when surgical codes are billed alongside neurology services. |
78 | Unplanned return to operating/procedure room by same physician following initial procedure | Not applicable to routine PLA testing; rarely used if laboratory procedure is interrupted and repeated intra-procedurally. |
80 | Assistant surgeon | Not applicable to laboratory testing; used when an assistant surgeon is billed for a surgical service related to the patient encounter. |
QK | Medical direction of two, three, or four assistants | Not typically applicable; use only if payer requires documenting medical direction for ancillary personnel. |
FX | Unusual anesthesia events or modifiers used for special circumstances | Rarely used; include if payer requires specifying extenuating circumstances affecting service delivery. |
FY | Two surgeons — overlapping service | Not applicable to PLA testing; included only for crosswalks with perioperative billing. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 2084P0800X | Neurology | Ordering specialists who commonly request expanded ataxia genetic testing. |
| 208500000X | Medical Genetics | Clinical geneticists who interpret complex genetic test results and counsel families. |
| 2086S0102X | Neuromuscular Medicine | Specialists evaluating inherited movement disorders and coordinating testing. |
| 207Q00000X | Clinical Laboratory | Laboratories and pathologists responsible for performing the technical PLA testing. |
| 363L00000X | Genetic Counseling | Providers who deliver pre- and post-test counseling based on results. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
G11.1 | Early-onset cerebellar ataxia | Common indication for comprehensive ataxia genetic testing, including repeat expansion analysis. |
G11.3 | Other hereditary ataxia | Directly relevant as the test evaluates multiple hereditary ataxia loci for repeat expansions and sequence variants. |
G11.4 | Hereditary spastic paraplegia | Overlapping clinical features with ataxia; testing may be part of broader genetic evaluation. |
R26.0 | Ataxic gait | Symptom code frequently used to justify diagnostic genetic testing for ataxia etiologies. |
R47.1 | Dysarthria and anarthria | Speech disturbance that accompanies cerebellar dysfunction and supports ordering expanded ataxia testing. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
81292 | Huntingtin (HTT) (e.g., Huntington disease) gene analysis; detection of CAG repeat expansions | Another repeat expansion test used in differential diagnosis when chorea or mixed movement disorder is present; may be ordered if clinical features overlap. |
81324 | FMR1 (fragile X mental retardation 1) (e.g., fragile X syndrome); CGG repeat analysis | Fragile X–associated tremor/ataxia syndrome can present with ataxia; testing may be performed in parallel for broader differential. |
81479 | Unlisted molecular pathology procedure | Used when a specific proprietary PLA lacks a direct crosswalk or when additional custom molecular testing is ordered alongside 0216U. |
0018U | Brain tumor molecular profiling (example PLA) | Other PLA codes illustrate laboratory-specific proprietary testing workflows; billed separately when applicable. |
99213 | Office or other outpatient visit for the evaluation and management of an established patient | Represents the outpatient clinical visit where ordering, consent discussion, and result review occur; billed by the clinician ordering 0216U. |