CPT® Code 81284

Official Description

FXN (frataxin) (eg, Friedreich ataxia) gene analysis; evaluation to detect abnormal (expanded) alleles

Common Language Description

The CPT® Code 81284 pertains to the molecular genetic testing of the FXN (frataxin) gene, which is specifically associated with Friedreich ataxia, a progressive neuromuscular disorder characterized by a range of debilitating symptoms. The FXN gene is located on the long (q) arm of chromosome 9 at position 21.11 (9q21.11) and plays a crucial role in coding for a protein that is essential for iron metabolism, antioxidant protection, and energy production within the body. This protein is distributed throughout various tissues, with the highest concentrations found in the heart, spinal cord, liver, pancreas, and skeletal muscles. Friedreich ataxia manifests through a variety of symptoms, including impaired balance and coordination, decreased strength and sensation in the extremities, muscle stiffness and spasticity, as well as potential speech, hearing, and visual impairments. Additionally, individuals may experience hypertrophic cardiomyopathy, diabetes, and scoliosis. The onset of symptoms typically occurs between the ages of 5 and 15 in approximately 75% of cases, while the remaining 25% may not exhibit symptoms until after the age of 25. The FXN gene is notable for its unique DNA allele, which consists of a trinucleotide repeat pattern of three amino acids: glycine, alanine, and alanine (GAA). In healthy individuals, this repeat occurs fewer than 33 times, with short normal alleles having fewer than 12 repeats and long normal alleles ranging from 12 to 33 repeats. In most affected individuals, two (homozygous) genes will exhibit expanded trinucleotide repeats located on intron 1 of the FXN gene. A small percentage, about 2%, may present with one gene having expanded repeats and the other gene exhibiting a point mutation or deletion. The code 81284 is utilized to report the FXN gene analysis aimed at evaluating the presence of these abnormal, expanded alleles.

1. Indications

The FXN (frataxin) gene analysis, represented by CPT® Code 81284, is indicated for the evaluation of individuals suspected of having Friedreich ataxia. The following conditions and symptoms may warrant this genetic testing:

Impaired Balance and Coordination - Individuals may exhibit difficulties in maintaining balance and coordinating movements, which are hallmark symptoms of Friedreich ataxia.
Decreased Strength and Sensation - Patients may experience reduced muscle strength and altered sensation in the extremities, impacting their ability to perform daily activities.
Muscle Stiffness and Spasticity - The presence of muscle stiffness and spasticity can lead to discomfort and mobility challenges for affected individuals.
Speech, Hearing, and Visual Impairments - Some patients may develop difficulties with speech, hearing, or vision, further complicating their condition.
Hypertrophic Cardiomyopathy - This condition, characterized by the thickening of the heart muscle, is commonly associated with Friedreich ataxia and may require monitoring.
Diabetes - The occurrence of diabetes in conjunction with other symptoms may suggest the need for genetic evaluation.
Scoliosis - The development of scoliosis, or curvature of the spine, is another potential indicator for testing.

2. Procedure

The procedure for conducting the FXN gene analysis involves several key steps to ensure accurate detection of abnormal alleles. The following outlines the procedural steps:

Step 1: Sample Collection - A biological sample, typically blood or saliva, is collected from the patient. This sample serves as the source of DNA for analysis.
Step 2: DNA Extraction - The DNA is extracted from the collected sample using standardized laboratory techniques to isolate the genetic material necessary for testing.
Step 3: PCR Amplification - Polymerase chain reaction (PCR) is employed to amplify specific regions of the FXN gene, particularly intron 1, where the trinucleotide repeats are located. This step is crucial for ensuring that sufficient quantities of DNA are available for analysis.
Step 4: Analysis of Trinucleotide Repeats - The amplified DNA is analyzed to detect the presence of expanded trinucleotide repeats. This involves comparing the number of repeats to established thresholds for normal and abnormal alleles.
Step 5: Interpretation of Results - The results are interpreted by a qualified geneticist or laboratory professional, who assesses the presence of abnormal alleles and determines the implications for the patient’s health.

3. Post-Procedure

After the FXN gene analysis is completed, patients may receive counseling regarding the results. If abnormal alleles are detected, further discussions may include potential implications for the patient's health, family planning considerations, and the possibility of additional testing for family members. Follow-up appointments may be scheduled to monitor any developing symptoms associated with Friedreich ataxia, and to provide ongoing support and management options tailored to the patient's needs.

Short Descr	FXN GENE DETC ABNOR ALLELES
Medium Descr	FXN GENE ANALYSIS EVAL DETECT ABNORMAL ALLELES
Long Descr	FXN (frataxin) (eg, Friedreich ataxia) gene analysis; evaluation to detect abnormal (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

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.

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.