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The CPT® Code 81336 pertains to the molecular genetic testing of the SMN1 (survival of motor neuron 1, telomeric) gene, specifically focusing on the full gene sequence analysis. This testing is crucial for diagnosing spinal muscular atrophy (SMA), a severe neuromuscular disorder characterized by the degeneration of motor neurons, leading to muscle weakness and atrophy. The SMN1 gene, located on the long arm of chromosome 5 at position 13.2 (5q13.2), plays a vital role in producing a protein essential for the survival of motor neurons. This protein facilitates the transmission of signals from the nervous system to voluntary muscles, which are responsible for critical functions such as walking, talking, and swallowing. In addition to the SMN1 gene, the analysis may also involve the SMN2 (survival of motor neuron 2, centromeric) gene, which, while similar, produces a less functional protein. The SMN1 gene is responsible for approximately 85-90% of the protein required by the body, whereas the SMN2 gene contributes the remaining 10-15%. The presence of multiple copies of these genes can influence the severity of SMA and the risk of transmission to offspring. In most cases, SMA is caused by deletion mutations in both copies of the SMN1 gene, while a smaller percentage of cases involve one deletion mutation and another type of mutation that disrupts gene function. The full gene sequence analysis provided by CPT® Code 81336 allows for a comprehensive examination of the SMN1 gene, identifying functional variants and assessing the genetic markers associated with SMA. This detailed analysis is essential for understanding the genetic underpinnings of the disease and for informing potential treatment options and family planning considerations.
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The molecular genetic testing using CPT® Code 81336 is indicated for the diagnosis and assessment of spinal muscular atrophy (SMA). The following conditions and scenarios warrant this testing:
The procedure for CPT® Code 81336 involves several detailed steps to ensure accurate analysis of the SMN1 gene. The following outlines the procedural steps:
After the completion of the genetic testing procedure, the following post-procedure considerations are important:
Patients may receive genetic counseling to discuss the results of the testing, especially if mutations are identified. This counseling can provide insights into the implications of the findings for the patient and their family, including the risk of SMA in offspring and potential treatment options. Additionally, follow-up testing may be recommended for family members to assess their carrier status or to identify at-risk individuals. It is essential for healthcare providers to ensure that patients understand the results and the next steps in management or treatment based on the genetic findings.
| Short Descr | SMN1 GENE FULL GENE SEQUENCE | Medium Descr | SMN1 GENE ANALYSIS FULL GENE SEQUENCE | Long Descr | SMN1 (survival of motor neuron 1, telomeric) (eg, spinal muscular atrophy) gene analysis; full gene sequence | Status Code | Statutory Exclusion (from MPFS, may be paid under other methodologies) | Global Days | XXX - Global Concept Does Not Apply | PC/TC Indicator (26, TC) | 9 - Not Applicable | Multiple Procedures (51) | 9 - Concept does not apply. | Bilateral Surgery (50) | 9 - Concept does not apply. | Physician Supervisions | 09 - Concept does not apply. | Assistant Surgeon (80, 82) | 9 - Concept does not apply. | Co-Surgeons (62) | 9 - Concept does not apply. | Team Surgery (66) | 9 - Concept does not apply. | Diagnostic Imaging Family | 99 - Concept Does Not Apply | CLIA Waived (QW) | No | APC Status Indicator | Service Paid under Fee Schedule or Payment System other than OPPS | Type of Service (TOS) | 5 - Diagnostic Laboratory | Berenson-Eggers TOS (BETOS) | none | MUE | 1 |
| 90 | Reference (outside) laboratory: when laboratory procedures are performed by a party other than the treating or reporting physician or other qualified health care professional, the procedure may be identified by adding modifier 90 to the usual procedure number. | 59 | Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25. | GW | Service not related to the hospice patient's terminal condition | XS | Separate structure, a service that is distinct because it was performed on a separate organ/structure |
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| 2019-01-01 | Added | Added |
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