81269 HBA1/HBA2 (alpha globin 1 and alpha globin 2) (eg, alpha thalassemia, Hb Bart hydrops fetalis syndrome, HbH disease), gene analysis; duplication/deletion variants

Name of the Procedure:

Alpha Globin Gene Analysis (HBA1 and HBA2) for Duplication/Deletion Variants

Summary

This genetic test analyzes the alpha globin 1 (HBA1) and alpha globin 2 (HBA2) genes to identify any duplications or deletions that could lead to disorders like alpha thalassemia. The test helps diagnose conditions involving abnormal hemoglobin production.

Purpose

This procedure aims to detect genetic variations in the alpha globin genes that can cause alpha thalassemia, Hb Bart hydrops fetalis syndrome, and HbH disease. By identifying these genetic anomalies, healthcare providers can diagnose, manage, and plan appropriate treatment for affected individuals.

Indications

• Symptoms of anemia, such as fatigue, weakness, or pallor.
• Family history of alpha thalassemia or related hemoglobin abnormalities.
• Presence of abnormal hemoglobin patterns in routine blood tests.
• Consanguineous parents planning to conceive.
• Pregnant women at risk of carrying a fetus with hemoglobin abnormalities.

Preparation

• No special preparation such as fasting is typically required.
• A thorough medical history, including family history of hemoglobin disorders, is taken.
• Pre-test genetic counseling may be recommended to discuss the implications of the results.

Procedure Description

1. A blood sample is collected from the patient, usually from a vein in the arm.
2. The sample is sent to a specialized laboratory where DNA is extracted.
3. Molecular techniques like Multiplex Ligation-dependent Probe Amplification (MLPA) or Polymerase Chain Reaction (PCR) are used to detect duplications or deletions in the HBA1 and HBA2 genes.
4. The genetic material is analyzed for specific variations indicative of alpha thalassemia or related conditions.

Duration

The blood collection process takes about 5-10 minutes. Laboratory analysis and result interpretation usually take 1-2 weeks.

Setting

• Typically performed in a hospital or outpatient clinic.
• The analysis is conducted in a specialized genetic testing laboratory.

Personnel

• Phlebotomist or nurse for blood collection.
• Geneticist or laboratory technician for sample analysis.
• Genetic counselor or healthcare provider for result interpretation and patient consultation.

Risks and Complications

• Minor risks associated with blood draw, such as bruising or infection at the puncture site.
• Very rare risk of incorrect or inconclusive results needing further testing for clarification.

Benefits

• Accurate diagnosis of genetic conditions related to alpha globin variants.
• Information to guide treatment and management of disorders like alpha thalassemia.
• Helps in genetic counseling and family planning decisions.

Recovery

• No significant recovery time is needed.
• Patients can resume normal activities immediately after the blood draw.

Alternatives

• Hemoglobin electrophoresis or high-performance liquid chromatography (HPLC) to assess abnormal hemoglobin types.
• Other genetic tests targeting different regions or mechanisms of alpha globin gene disruption.

Patient Experience

• Mild discomfort or a brief sting during blood draw.
• Anxiety associated with awaiting results may be managed through counseling and support.
• Relief from receiving a definitive diagnosis and a clear treatment plan.

By understanding this information, patients and healthcare providers can make informed decisions regarding alpha globin gene analysis and related genetic testing.