CPT® Code 81285

Official Description

FXN (frataxin) (eg, Friedreich ataxia) gene analysis; characterization of alleles (eg, expanded size)

Common Language Description

The CPT® Code 81285 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 trinucleotide repeats while the other gene may contain a point mutation or deletion. The analysis performed under CPT® Code 81285 is critical for characterizing these expanded alleles, determining their size, and identifying any similarities or differences, which can provide valuable insights into the genetic underpinnings of Friedreich ataxia.

1. Indications

The molecular genetic testing for the FXN (frataxin) gene analysis, as described by CPT® Code 81285, is indicated for the following conditions:

Friedreich Ataxia - A progressive neuromuscular disorder characterized by symptoms such as impaired balance and coordination, decreased strength and sensation in the extremities, muscle stiffness and spasticity, and potential complications including hypertrophic cardiomyopathy, diabetes, and scoliosis.
Genetic Counseling - Individuals with a family history of Friedreich ataxia may undergo testing to assess the risk of inheritance and to inform family planning decisions.
Diagnosis Confirmation - Testing may be performed to confirm a diagnosis of Friedreich ataxia in symptomatic individuals, particularly when clinical features are present.

2. Procedure

The procedure for FXN (frataxin) gene analysis under CPT® Code 81285 involves several key steps to ensure accurate characterization of the alleles associated with Friedreich ataxia:

Sample Collection - A biological sample, typically blood or saliva, is collected from the patient to obtain DNA for analysis. This sample serves as the basis for the genetic testing.
DNA Extraction - The DNA is extracted from the collected sample using standardized laboratory techniques to isolate the genetic material necessary for testing.
Allele Characterization - The extracted DNA is analyzed to characterize the alleles of the FXN gene. This involves determining the size of the expanded trinucleotide repeats and identifying any variations or mutations present in the gene.
Data Interpretation - The results of the analysis are interpreted to identify the presence of expanded alleles, their characteristics, and any potential implications for the patient's health and family members.
Reporting - A detailed report is generated, summarizing the findings of the FXN gene analysis, including the size of the alleles and any identified genetic markers. This report is then provided to the healthcare provider for further clinical decision-making.

3. Post-Procedure

After the FXN gene analysis is completed, patients may receive counseling regarding the results, especially if expanded alleles are identified. This counseling can include discussions about the implications of the findings for the patient's health, potential symptoms, and the risk of transmission to offspring. Follow-up appointments may be scheduled to monitor any emerging symptoms associated with Friedreich ataxia, and additional genetic counseling may be recommended for family members to understand their potential risk. It is important for healthcare providers to ensure that patients are informed about the nature of the disorder, available management options, and support resources.

Short Descr	FXN GENE CHARAC ALLELES
Medium Descr	FXN GENE ANALYSIS CHARACTERIZATION ALLELES
Long Descr	FXN (frataxin) (eg, Friedreich ataxia) gene analysis; characterization of alleles (eg, expanded size)
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