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The CPT® Code 81271 pertains to the molecular genetic testing of the HTT (huntingtin) gene, specifically aimed at evaluating and detecting abnormal alleles associated with Huntington disease. Huntington disease is a progressive neurodegenerative disorder characterized by a range of symptoms including cognitive impairment, dementia, apathy, depression, anxiety, and extrapyramidal body movements. The HTT gene, located on the short (p) arm of chromosome 4 at position 16.3 (4p16.3), encodes a protein that plays a crucial role in the function of nerve cells, which is essential for normal brain development. This gene is involved in various cellular processes, including chemical signaling, protein binding, and cellular protection against self-destruction. The HTT gene features a unique DNA allele characterized by a trinucleotide repeat pattern of three amino acids: cysteine, alanine, and glycine (CAG). Typically, this CAG sequence repeats between 10 to 35 times in healthy individuals. However, when the number of repeats exceeds this range, it can lead to the production of an elongated protein that is fragile and prone to fragmentation, resulting in the accumulation of toxic aggregates within nerve cells. The presence of 27 to 35 CAG repeats is classified as a pre-mutation, where individuals remain asymptomatic but face an increased risk of allele expansion in subsequent generations. Alleles with 36 to 39 CAG repeats may present with mild or no symptoms, while those with 40 to 50 CAG repeats typically manifest symptoms in adulthood. In contrast, individuals with more than 60 CAG repeats often exhibit symptoms during childhood or adolescence. The analysis performed under CPT® Code 81271 is crucial for identifying these expanded alleles, thereby aiding in the diagnosis and understanding of Huntington disease.
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The HTT gene analysis (CPT® Code 81271) is indicated for the evaluation of individuals who may be at risk for Huntington disease. The following conditions and symptoms warrant this genetic testing:
The procedure for conducting the HTT gene analysis involves several key steps to ensure accurate detection of abnormal alleles:
After the HTT gene analysis is completed, patients may receive genetic counseling to discuss the results and their implications. If abnormal alleles are detected, further discussions regarding the potential onset of Huntington disease, family planning, and available support resources may be necessary. Patients may also be advised on monitoring for symptoms and the importance of regular follow-up with healthcare providers. It is essential for individuals to understand the psychological and emotional impact of the results, and support services may be recommended to assist them in coping with the information received.
| Short Descr | HTT GENE DETC ABNOR ALLELES | Medium Descr | HTT GENE ANALYSIS DETECT ABNORMAL ALLELES | Long Descr | HTT (huntingtin) (eg, Huntington disease) gene analysis; evaluation to detect abnormal (eg, expanded) alleles | 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. | GA | Waiver of liability statement issued as required by payer policy, individual case | GW | Service not related to the hospice patient's terminal condition | 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. | GZ | Item or service expected to be denied as not reasonable and necessary | XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service |
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| 2019-01-01 | Added | Added |
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