81363 HBB (hemoglobin, subunit beta) (eg, sickle cell anemia, beta thalassemia, hemoglobinopathy); duplication/deletion variant(s)

Name of the Procedure:

Hemoglobin, Subunit Beta (HBB) Duplication/Deletion Variant Analysis; also known as beta-globin gene testing, specific to conditions like sickle cell anemia, beta thalassemia, and other hemoglobinopathies.

Summary

This genetic test looks for duplications or deletions in the beta-globin gene (HBB). It’s important for diagnosing and managing conditions like sickle cell anemia and beta thalassemia, which affect the hemoglobin in red blood cells.

Purpose

The procedure helps to identify genetic abnormalities in the beta-globin gene. The goal is to diagnose conditions like sickle cell anemia or thalassemias, guiding treatment plans tailored to the specific genetic variant.

Indications

• Symptoms of hemolytic anemia, such as fatigue, pallor, and jaundice.
• Family history of hemoglobinopathies.
• Positive newborn screening for hemoglobinopathies.
• Unexplained high reticulocyte count and/or abnormal hemoglobin electrophoresis.

Preparation

• No special preparation is usually required.
• A routine blood sample is taken for analysis.
• Patients might need to provide detailed family medical history.

Procedure Description

1. Sample Collection: A blood sample is drawn from the patient using standard phlebotomy techniques.
2. Laboratory Analysis: The sample is sent to a specialized lab where DNA is extracted from the blood cells.
3. Genetic Testing: Molecular techniques such as Multiplex Ligation-dependent Probe Amplification (MLPA) or Comparative Genomic Hybridization (CGH) arrays are used to detect duplications or deletions in the HBB gene.

Duration

The blood sample collection takes approximately 5-10 minutes. Laboratory analysis typically takes several days to weeks, depending on the testing complexity.

Setting

The procedure is performed in a clinical laboratory setting for the blood draw, often within a hospital, outpatient clinic, or specialized genetic testing facility.

Personnel

• Phlebotomist or nurse for blood sample collection.
• Medical geneticist or specialized laboratory technician for sample analysis.

Risks and Complications

• Common: Minor discomfort or bruising at the blood draw site.
• Rare: Infection at the puncture site, fainting during blood draw.

Benefits

• Accurate diagnosis of hemoglobinopathies, leading to appropriate and effective treatment.
• Identification of carriers which is particularly useful for family planning and genetic counseling.
• Better management of symptoms through personalized care plans.

Recovery

• Typically none required for the procedure itself.
• Post-blood draw, the patient can resume normal activities immediately.
• Follow-up involves discussing test results with the healthcare provider.

Alternatives

• Hemoglobin electrophoresis or high-performance liquid chromatography (HPLC) for identifying abnormal hemoglobin types.
• DNA sequencing for detailed genetic analysis.
• Pros: Alternatives might provide additional detail or identify other types of hemoglobinopathies.
• Cons: May not be as specific for detecting duplications/deletions as HBB variant analysis.

Patient Experience

• During: Slight pinch or discomfort during blood draw.
• After: Generally, no pain or complications; normal daily activities can be resumed immediately.
• Pain management: Usually not necessary, but a warm compress can alleviate discomfort if it arises.