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The CPT® Code 81185 pertains to the molecular genetic testing of the CACNA1A gene, which encodes the calcium voltage-gated channel subunit alpha1 A. This gene analysis is specifically aimed at identifying mutations associated with spinocerebellar ataxia type 6 (SCA6), a neurodegenerative disorder characterized by a gradual decline in motor coordination due to the degeneration of the cerebellum and spinal cord. The CACNA1A gene is situated on the short arm of chromosome 19 at the position 19p13.13 and plays a crucial role in the formation of calcium channels that facilitate the transport of calcium ions across cell membranes. These calcium channels are essential for neuronal communication and the release of neurotransmitters, which are vital for proper brain function. The gene contains a specific region that features a trinucleotide repeat sequence of CAG (cytosine-adenine-guanine), which typically repeats between 4 to 18 times in healthy individuals. However, in individuals with SCA6, this repeat can expand to between 20 to 33 times, which is associated with the onset and severity of symptoms. The number of repeats influences the age at which symptoms manifest, with fewer repeats correlating to a later onset. Symptoms of SCA6 may include uncoordinated gait (ataxia), dystonia, tremors, loss of coordination in the arms, difficulties in speech (dysarthria), involuntary eye movements (nystagmus), and double vision. The analysis performed under CPT® Code 81185 involves a comprehensive sequencing of the CACNA1A gene to identify functional variants by comparing segments of the gene for similarities and differences. This process includes the examination of introns, exons, and regulatory elements, as well as the identification of genetic markers through the detection of point mutations or single nucleotide polymorphisms. This detailed genetic analysis is crucial for understanding the genetic basis of SCA6 and for identifying at-risk family members, as it provides insights into the hereditary nature of the condition.
© Copyright 2025 Coding Ahead. All rights reserved.
The molecular genetic testing for the CACNA1A gene analysis (CPT® Code 81185) is indicated for the following conditions:
The procedure for the CACNA1A gene analysis involves several detailed steps to ensure accurate identification of mutations associated with SCA6. The following steps outline the process:
After the completion of the CACNA1A gene analysis, patients may receive genetic counseling to discuss the results and their implications. This counseling is essential for understanding the hereditary nature of SCA6, potential risks for family members, and available options for monitoring and managing symptoms. Patients may also be advised on follow-up testing or additional evaluations based on the findings of the genetic analysis. It is important for healthcare providers to ensure that patients understand the significance of the results and the potential impact on their health and family planning.
| Short Descr | CACNA1A GENE FULL GENE SEQ | Medium Descr | CACNA1A GENE ANALYSIS FULL GENE SEQUENCE | Long Descr | CACNA1A (calcium voltage-gated channel subunit alpha1 A) (eg, spinocerebellar ataxia) 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. | XS | Separate structure, a service that is distinct because it was performed on a separate organ/structure | GW | Service not related to the hospice patient's terminal condition | XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service | 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. | GA | Waiver of liability statement issued as required by payer policy, individual case |
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| 2019-01-01 | Added | Added |
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