CPT® Code 81174

Official Description

AR (androgen receptor) (eg, spinal and bulbar muscular atrophy, Kennedy disease, X chromosome inactivation) gene analysis; known familial variant

Common Language Description

The CPT® Code 81174 pertains to the analysis of the androgen receptor (AR) gene, specifically focusing on known familial variants. This molecular genetic testing is crucial for identifying mutations within the AR gene that are linked to various conditions, including androgen inactivation syndrome, spinal and bulbar muscular atrophy, Kennedy disease, androgenetic alopecia, and polycystic ovarian syndrome. The AR gene is situated on the long arm of the X chromosome at position 12 (Xq12) and plays a vital role in the development of male characteristics by encoding a protein that binds to androgen hormones, such as testosterone. This binding process is essential for regulating the development of male traits during both gestation and puberty. The normal function of the AR gene involves a specific trinucleotide repeat of cytosine-adenine-guanine (CAG), which typically ranges from fewer than 10 to about 36 repeats. However, in conditions like spinal and bulbar muscular dystrophy, the CAG repeats can be significantly expanded, numbering from 38 to over 60. This expansion is associated with symptoms such as progressive muscle wasting, gynecomastia, testicular atrophy, and fertility issues, predominantly affecting males aged 30 to 60. Mutations in the AR gene can lead to androgen insensitivity syndrome, which results in male feminization due to various genetic alterations, including single base pair changes or insertions and deletions of multiple base pairs. Additionally, small mutations in the AR gene are implicated in androgenetic alopecia, leading to characteristic hair loss in both males and females. In women, AR gene alterations may contribute to the development of polycystic ovarian syndrome, which is characterized by symptoms such as hirsutism, acne, and fertility challenges. The CPT® Code 81174 specifically reports the analysis of a known familial variant within the AR gene, allowing for the identification of at-risk family members. This targeted approach is essential for genetic counseling and management of hereditary conditions associated with the AR gene.

1. Indications

The CPT® Code 81174 is indicated for the molecular genetic testing of individuals who may have a known familial variant in the androgen receptor (AR) gene. This testing is particularly relevant for the following conditions:

Androgen Inactivation Syndrome - A condition where the body is unable to respond to androgens, leading to various developmental issues.
Spinal and Bulbar Muscular Atrophy - A neuromuscular disorder characterized by progressive muscle weakness and atrophy, primarily affecting proximal muscles.
Kennedy Disease - A genetic disorder that affects motor neurons, leading to muscle weakness and atrophy, often associated with hormonal changes.
Androgenetic Alopecia - A common form of hair loss in both men and women, linked to genetic variations in the AR gene.
Polycystic Ovarian Syndrome - A hormonal disorder in women that can lead to irregular menstrual cycles, hirsutism, and fertility issues, potentially influenced by AR gene mutations.

2. Procedure

The procedure associated with CPT® Code 81174 involves several key steps to ensure accurate analysis of the AR gene for known familial variants:

Step 1: Sample Collection - A biological sample, typically blood or saliva, is collected from the patient. This sample contains the DNA necessary for genetic analysis.
Step 2: DNA Extraction - The DNA is extracted from the collected sample using standardized laboratory techniques to isolate the genetic material for testing.
Step 3: Targeted Gene Analysis - The specific exon sequence of the AR gene is analyzed to detect known familial variants. This step may involve techniques such as polymerase chain reaction (PCR) and sequencing to identify any mutations present.
Step 4: Data Interpretation - The results of the genetic analysis are interpreted by qualified geneticists or laboratory professionals. They compare the findings against known familial variants to determine the presence of any mutations.
Step 5: Reporting Results - A comprehensive report is generated, detailing the findings of the analysis, including any identified familial variants and their potential implications for the patient and their family members.

3. Post-Procedure

After the procedure associated with CPT® Code 81174, patients may receive genetic counseling based on the results of the AR gene analysis. This counseling is essential for understanding the implications of the findings, particularly for family members who may also be at risk for the identified conditions. Patients may be advised on potential monitoring or management strategies depending on the results. Additionally, follow-up testing or further genetic analysis may be recommended if a known familial variant is detected, ensuring that at-risk relatives can be appropriately evaluated.

Short Descr	AR GENE KNOWN FAMIL VARIANT
Medium Descr	AR GENE ANALYSIS KNOWN FAMILIAL VARIANT
Long Descr	AR (androgen receptor) (eg, spinal and bulbar muscular atrophy, Kennedy disease, X chromosome inactivation) gene analysis; known familial variant
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