CPT® Code 81224

Official Description

CFTR (cystic fibrosis transmembrane conductance regulator) (eg, cystic fibrosis) gene analysis; intron 8 poly-T analysis (eg, male infertility)

Common Language Description

Molecular genetic testing is a critical diagnostic tool used to identify specific mutations in the CFTR gene, which is located on chromosome 7. This gene is responsible for encoding the cystic fibrosis transmembrane conductance regulator protein, which plays a vital role in the regulation of salt and water transport across epithelial cell membranes. Mutations in the CFTR gene are primarily associated with cystic fibrosis (CF), a genetic disorder that affects the respiratory, digestive, and reproductive systems. Additionally, these mutations can lead to congenital bilateral absence of the vas deferens (CBAVD), a condition that can result in male infertility. The testing process involves analyzing the gene for specific mutations, particularly focusing on the intron 8 poly-T region, which is crucial for understanding the genetic basis of these conditions. Males presenting with symptoms such as azoospermia (absence of sperm in semen), low semen ejaculatory volume, and the absence of the vas deferens as observed through clinical examination or ultrasound are considered suitable candidates for this molecular genetic testing. The intron 8 poly-T analysis serves as a reflex test that is conducted when a known disease-causing mutation, such as the R117H mutation, is detected. This analysis evaluates the poly-T tract, which consists of a series of thymidine bases and has three common variants: 5T, which is associated with a penetrant mutation, and 7T and 9T, which are classified as polymorphic variants. Understanding these genetic variations is essential for accurate diagnosis and management of conditions related to CFTR gene mutations.

1. Indications

The molecular genetic testing for the CFTR gene analysis is indicated for specific conditions and symptoms that suggest the presence of mutations in the CFTR gene. The following are the primary indications for this testing:

Cystic Fibrosis (CF) Individuals presenting with symptoms consistent with cystic fibrosis, a genetic disorder characterized by severe respiratory and digestive issues, may undergo this testing to confirm the diagnosis.
Congenital Bilateral Absence of the Vas Deferens (CBAVD) Males diagnosed with congenital bilateral absence of the vas deferens, which can lead to infertility, are candidates for this genetic analysis to determine if a CFTR mutation is present.
Azoospermia Males exhibiting azoospermia, or the absence of sperm in the ejaculate, may be tested to identify potential genetic causes related to CFTR mutations.
Low Semen Ejaculatory Volume Males with low semen ejaculatory volume may also be evaluated through this testing to assess for underlying genetic factors.
Clinical Examination Findings Patients who show clinical examination or ultrasound findings indicating the absence of the vas deferens are recommended for this genetic testing to explore the possibility of CFTR gene mutations.

2. Procedure

The procedure for conducting the CFTR gene analysis, specifically the intron 8 poly-T analysis, involves several key steps that ensure accurate identification of mutations. 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 the genetic analysis.
Step 2: DNA Extraction The DNA is extracted from the collected sample using standardized laboratory techniques. This step is crucial for isolating the genetic material needed for analysis.
Step 3: Mutation Analysis The extracted DNA is subjected to molecular genetic testing to identify specific mutations in the CFTR gene. This includes the examination of known mutations, such as the R117H mutation.
Step 4: Intron 8 Poly-T Analysis If a disease-causing mutation is identified, a reflex test for the intron 8 poly-T analysis is performed. This analysis focuses on the poly-T tract within intron 8 to determine the presence of the 5T, 7T, or 9T variants.
Step 5: Result Interpretation The results of the genetic testing are interpreted by qualified laboratory personnel, who assess the presence of mutations and their potential implications for the patient’s health.
Step 6: Reporting A comprehensive report is generated, detailing the findings of the genetic analysis, including any identified mutations and their clinical significance. This report is then provided to the referring physician for further evaluation and management.

3. Post-Procedure

After the CFTR gene analysis is completed, patients may receive counseling regarding the results and their implications. If a mutation is identified, healthcare providers may discuss potential treatment options, management strategies, and implications for family planning. It is essential for patients to understand the genetic basis of their condition and the potential for carrier status in family members. Follow-up appointments may be scheduled to address any questions or concerns regarding the results and to provide ongoing support and management as needed.

Short Descr	CFTR GENE INTRON POLY T
Medium Descr	CFTR GENE ANALYSIS INTRON 8 POLY-T ANALYSIS
Long Descr	CFTR (cystic fibrosis transmembrane conductance regulator) (eg, cystic fibrosis) gene analysis; intron 8 poly-T analysis (eg, male infertility)
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)	T1H - Lab tests - other (non-Medicare fee schedule)
MUE	1
CCS Clinical Classification	234 - Pathology

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