Billing Code Overview

CPT code 0236U is a Proprietary Laboratory Analyses (PLA) code for the Genomic Unity® SMN1/2 Analysis from Variantyx Inc. The test evaluates the survival of motor neuron 1, telomeric (SMN1) and survival of motor neuron 2, centromeric (SMN2) genes using a PCR-free whole genome sequencing (WGS) platform with algorithmic data analysis to detect variants relevant to conditions such as spinal muscular atrophy.

Service type: Genomic sequencing and targeted gene analysis using PCR-free whole genome sequencing with algorithmic interpretation

Typical site of service: Clinical laboratory (blood or saliva specimen collection with testing performed in a specialized molecular/genomics laboratory)

Clinical Context

A pediatric or adult patient with a personal or family history suggestive of spinal muscular atrophy (SMA) presents for genetic testing to confirm carrier status, diagnostic evaluation of neuromuscular weakness, or to inform reproductive planning. Typical indications include: progressive proximal muscle weakness, hypotonia in infants, delayed motor milestones, or a known family history of SMN1 pathogenic variants. The clinician (pediatric neurologist, medical geneticist, or genetic counselor) orders the Genomic Unity® SMN1/2 Analysis (0236U) using a blood or saliva specimen. The specimen is collected at an outpatient clinic, hospital ambulatory lab, or at-home collection kit per laboratory instructions and shipped to Variantyx Inc. for processing.

Laboratory workflow: the lab performs PCR-free whole genome sequencing (WGS) with algorithmic analysis focused on copy number and sequence variants in SMN1 and SMN2. Results include SMN1 copy number, SMN2 copy number, and detection of pathogenic or likely pathogenic sequence variants relevant to SMA. The laboratory report is returned to the ordering provider with interpretation to support diagnostic confirmation, carrier screening, prognostic counseling, or therapeutic decision-making such as eligibility for SMA-targeted therapies or inclusion in clinical trials.

Typical site of service: outpatient clinic, hospital outpatient laboratory, or reference laboratory with remote specimen collection.

Coding Specifications

22 | Increased procedural services | Unusual laboratory complexity beyond standard processing when documented by the lab

26 | Professional component | When reporting only the professional interpretive component separate from technical processing (rare for PLAs)

52 | Reduced services | If testing is partially performed or limited compared with full assay (documented reduction)

53 | Discontinued procedure | If specimen collection or testing is aborted prior to completion for clinical reasons

62 | Two surgeons | Not typically applicable to lab testing; included for completeness when multiple providers share responsibilities in a diagnostic pathway

78 | Unplanned return to the operating/procedure room by same physician | Not applicable to this laboratory test; reserved for procedural contexts

80 | Assistant surgeon | Not applicable to this laboratory test; reserved for surgical contexts

QK | CLIA waived? (modifier historically used for certain lab staffing) | Rare; used when specific billing rules require identification of laboratory personnel or arrangements (use per payer policy)

QX | CRNA service with physician direction | Not applicable to this laboratory test; clinical contexts only

QY | Medical direction of two or more CRNAs | Not applicable to this laboratory test

TC | Technical component | When reporting only the technical component of the test (instrumentation, sequencing) separate from professional interpretation

SH | Catastrophic or emergent services | Not typically used for genetic testing

SJ | Imagery or special diagnostic modifier | Rare for laboratory testing; check payer-specific guidance

Associated Provider Taxonomies

207L00000X | Clinical Genetics / Genetic Counseling | Orders and interprets genetic testing for carrier screening and diagnostic evaluation

207R00000X | Neurology | Evaluates adults with neuromuscular weakness and coordinates genetic testing

207X00000X | Clinical Pathology / Molecular Pathology | Laboratory specialists overseeing WGS-based diagnostic testing

2080P0201X | Pediatric Medicine | Pediatricians ordering initial testing for hypotonia or developmental delay

Related Diagnoses

G12.1 | Other inherited spinal muscular atrophy | Includes non–type I SMA presentations; genetic testing of SMN1/SMN2 is diagnostic

G12.8 | Other spinal muscular atrophies and related syndromes | For SMA variants not otherwise specified; test supports classification

Z14.01 | Genetic carrier status for spinal muscular atrophy | Used when documenting carrier screening or known carrier status confirmed by SMN1 analysis

R29.898 | Other symptoms and signs involving the nervous and musculoskeletal systems | Symptom code used when neuromuscular signs prompt diagnostic genetic testing

R62.0 | Delayed milestone in childhood | Used when motor milestone delay triggers evaluation including SMN1/SMN2 testing

Z31.5 | Encounter for genetic counseling | Used when testing is ordered as part of reproductive counseling and carrier screening

Related CPT Codes

81479 | Unlisted molecular pathology procedure | May be used when reporting additional molecular analyses not covered by a PLA code, subject to payer rules

81405 | Sequence analysis; full sequence of single gene or gene region (e.g., single gene sequencing) | May be reported when targeted sequencing or confirmatory testing of specific variants in SMN1/SMN2 is performed separately

G0452 | Pharmacogenetic testing (Medicare) — lab test for drug response | May be relevant in workflows where pharmacogenetic or therapy-eligibility testing is coordinated alongside SMA testing (payer dependent)

99000 | Handling and/or special processing, laboratory specimens (example code for specimen handling) | Used by some facilities for special specimen handling or shipping fees associated with remote collection and reference lab processing