CPT® Code 81364

Official Description

HBB (hemoglobin, subunit beta) (eg, sickle cell anemia, beta thalassemia, hemoglobinopathy); full gene sequence

Common Language Description

The CPT® Code 81364 pertains to the full gene sequence analysis of the hemoglobin, subunit beta (HBB) gene, which is crucial for diagnosing various hemoglobin disorders. The HBB gene is responsible for encoding the beta-globin protein, a vital component of hemoglobin found within red blood cells (RBCs). Hemoglobin itself is a protein complex made up of two beta-globin and two alpha-globin subunits, with the alpha-globin subunits encoded by the HBA gene. Each of these protein subunits is associated with iron-containing heme molecules that are essential for oxygen transport throughout the body. The HBB gene is located on the short arm of chromosome 11 at position 15.4. Mutations in the HBB gene can lead to significant health conditions, including sickle cell anemia, beta thalassemia, and other hemoglobinopathies. For instance, in sickle cell anemia, a specific mutation results in the substitution of the amino acid glutamic acid with valine at position 6 of the beta-globin subunit, leading to the formation of hemoglobin S (HbS). This abnormal hemoglobin causes red blood cells to adopt a sickle shape, which can obstruct blood flow and lead to various complications. Beta thalassemia is characterized by mutations that either reduce or completely halt the production of beta-globin, resulting in a deficiency of mature RBCs and subsequent oxygen delivery issues. Additionally, methemoglobinemia, a condition associated with the HBB gene, occurs when the normal ferrous iron in hemoglobin is replaced by ferric iron, impairing oxygen binding and leading to symptoms such as cyanosis and fatigue. The full gene sequence testing provided by CPT® Code 81364 is instrumental in identifying specific mutations associated with these disorders, evaluating abnormal hemoglobin types, and conducting preconception screenings for individuals with a family history of hemoglobinopathies. This comprehensive analysis is performed on a blood sample, which is obtained through a separate procedure and analyzed using advanced techniques such as polymerase chain reaction (PCR) and sequencing methods.

1. Indications

The full gene sequence analysis of the hemoglobin, subunit beta (HBB) gene, as represented by CPT® Code 81364, is indicated for several specific conditions and purposes, including:

Diagnosis of Sickle Cell Anemia - This test is utilized to confirm the presence of mutations in the HBB gene that lead to the production of hemoglobin S (HbS), which is responsible for sickle cell anemia.
Diagnosis of Beta Thalassemia - The analysis helps identify specific mutations associated with beta thalassemia, which can manifest as either beta-plus or beta-zero thalassemia, depending on the nature of the mutations affecting beta-globin production.
Evaluation of Hemoglobinopathies - This test is used to evaluate patients with abnormal hemoglobin types of unknown etiology, aiding in the identification of underlying genetic causes.
Carrier Screening - The test may be performed as a preconception screening tool to determine carrier status in individuals with a family history of hemoglobin disorders, allowing for informed reproductive choices.

2. Procedure

The procedure for conducting the full gene sequence analysis of the HBB gene involves several critical steps, which are outlined as follows:

Step 1: Sample Collection - A blood sample is obtained from the patient through a venipuncture procedure. This sample is essential for the subsequent genetic analysis and must be handled according to laboratory protocols to ensure integrity.
Step 2: DNA Extraction - The collected blood sample undergoes a process of DNA extraction, where the cellular components are separated to isolate the DNA, which contains the genetic information necessary for analysis.
Step 3: Polymerase Chain Reaction (PCR) - The extracted DNA is subjected to polymerase chain reaction (PCR) amplification. This technique allows for the selective replication of the HBB gene, ensuring that there is sufficient material for detailed analysis.
Step 4: Sequencing - Following amplification, the full gene sequence of the HBB gene is determined using sequencing methods. This step involves reading the nucleotide sequence of the gene to identify any mutations or variants present.
Step 5: Data Analysis - The resulting sequence data is analyzed to detect specific mutations associated with hemoglobin disorders. This analysis is critical for providing accurate diagnostic information and guiding clinical decisions.

3. Post-Procedure

After the completion of the full gene sequence analysis, several post-procedure considerations are important. The laboratory will compile the results of the genetic analysis, which will be interpreted by a qualified healthcare professional. Patients may receive counseling regarding the implications of the test results, especially if mutations associated with hemoglobin disorders are identified. Follow-up testing or additional evaluations may be recommended based on the findings. It is also essential for healthcare providers to discuss the potential impact of the results on family planning and the health of any offspring, particularly in cases where carrier status is determined. Overall, the post-procedure phase is crucial for ensuring that patients understand their results and the next steps in their care.

Short Descr	HBB FULL GENE SEQUENCE
Medium Descr	HBB FULL GENE SEQUENCE
Long Descr	HBB (hemoglobin, subunit beta) (eg, sickle cell anemia, beta thalassemia, hemoglobinopathy); full gene sequence
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
XU	Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service