delta beta-thalassemia

Delta Beta-Thalassemia: A Rare Genetic Disorder

Delta beta-thalassemia, also known as δβ thalassemia, is a rare genetic disorder characterized by the co-inheritance of delta and beta gene mutations [7][8]. This condition results from deletions or mutations in both the delta and beta genes on chromosome 11, leading to decreased or absent synthesis of the delta- and beta-globin chains [2].

Key Features

• Delta beta-thalassemia is a form of beta-thalassemia characterized by decreased or absent synthesis of the delta- and beta-globin chains with a compensatory increase in expression of fetal gamma-chain synthesis [10][11].
• The symptoms are mild to moderate depending on the severity of the disease, which can include mild, hypochromic anemia, slight hepatomegaly and/or splenomegaly, and other related complications [9].

Clinical Description

The heterozygous form of delta beta-thalassemia is clinically asymptomatic with mild microcytosis, while the homozygous form can present with more severe symptoms [12]. This condition is often associated with thalassemia intermedia and can be inherited from parents who are carriers of the disease [6].

Pathophysiology

The pathophysiology of delta beta-thalassemia parallels that of beta-thalassemia, except there is not an increased HbA2 since the delta chain is also affected [15]. The normal adult hemoglobin molecule (Hb A) consists of 2 pairs of chains designated alpha and beta, but in delta beta-thalassemia, the synthesis of both delta and beta globin chains is impaired.

References

[1] Not provided [2] by H Mansoori · 2016 · Cited by 20 — Delta beta (δβ)-thalassemia results from a deletion in both the delta and beta genes on chromosome 11. [3] Not provided [4] δ-Thalassemia is due to mutation of genes responsible for synthesis of δ-chain. A mutation that prevents formation of δ-chain is called δ 0. [5] Not provided [6] The condition is often associated with thalassemia intermedia and can be inherited from parents who are carriers of the disease. [7] by H Mansoori · 2016 · Cited by 20 — Delta beta (δβ)-thalassemia results from a deletion in both the delta and beta genes on chromosome 11. [8] δ-Thalassemia is due to mutation of genes responsible for synthesis of δ-chain. A mutation that prevents formation of δ-chain is called δ 0. [9] The symptoms are mild to moderate depending on the severity of the disease, which can include mild, hypochromic anemia, slight hepatomegaly and/or splenomegaly, and other related complications. [10] Delta beta-thalassemia is a form of beta-thalassemia characterized by decreased or absent synthesis of the delta- and beta-globin chains with a compensatory increase in expression of fetal gamma-chain synthesis. [11] Delta beta-thalassemia is a form of beta-thalassemia characterized by decreased or absent synthesis of the delta- and beta-globin chains with a compensatory increase in expression of fetal gamma-chain synthesis. [12] The heterozygous form of delta beta-thalassemia is clinically asymptomatic with mild microcytosis, while the homozygous form can present with more severe symptoms. [13] Not provided [14] Thalassemia is a hemoglobinopathy that is among the most common inherited disorders of hemoglobin production. [15] The pathophysiology of delta beta-thalassemia parallels that of beta-thalassemia, except there is not an increased HbA2 since the delta chain is also affected.

Delta-Beta Thalassemia Signs and Symptoms

Individuals with delta-beta thalassemia are usually asymptomatic, but microcytosis can occur where the red blood cells are abnormally small in size. This condition is characterized by decreased or absent synthesis of the delta- and beta-globin chains with a compensatory increase in expression of fetal gamma-chain synthesis [3].

In some cases, individuals may not exhibit any noticeable signs or symptoms, but when present, they can include:

• Microcytosis (small red blood cells)
• Mild anemia
• No significant jaundice or yellowish discoloration of the skin and sclera

It's essential to note that delta-beta thalassemia is often a mild form of thalassemia, and individuals with this condition may not experience severe symptoms like those associated with beta-thalassemia major [4].

References:

• [1] Signs and symptoms​​ An individual with delta-beta thalassemia is usually asymptomatic, however microcytosis can occur where the red blood cells are abnormally ...
• [3] characterized by decreased or absent synthesis of the delta- and beta-globin chains with a compensatory increase in expression of fetal gamma-chain synthesis. ...
• [4] What Are the Signs & Symptoms of Beta Thalassemia Intermedia or Major? · extreme tiredness · pale skin · shortness of breath · a fast heartbeat · moodiness or ...

Delta beta-thalassemia, also known as HbA2 beta thalassemia, is a rare form of thalassemia that affects the production of hemoglobin in red blood cells. Diagnostic tests for this condition are crucial to confirm the diagnosis and rule out other possible causes.

Laboratory Tests

Several laboratory tests can be used to diagnose delta beta-thalassemia:

• Routine Blood Tests: These tests, also known as complete blood counts (CBCs), may show anemia or low red blood cell count. However, they are not specific for thalassemia and cannot confirm the diagnosis [6].
• Hemoglobin Electrophoresis: This test separates different types of hemoglobin in the blood and can detect abnormal hemoglobins associated with delta beta-thalassemia [7].
• High-Performance Liquid Chromatography (HPLC): HPLC is a sensitive test that can detect small amounts of abnormal hemoglobin, including those found in delta beta-thalassemia [7].
• Free Erythrocyte Protoporphyrin (FEP) Test: This test measures the amount of porphyrin in red blood cells and may be useful in situations where the diagnosis is unclear [4].

Other Diagnostic Tests

In addition to laboratory tests, other diagnostic methods can be used to confirm delta beta-thalassemia:

• Molecular Characterization: This involves analyzing the DNA of the patient's hemoglobin genes to confirm the presence of mutations associated with delta beta-thalassemia [1].
• PCR Detection: Polymerase chain reaction (PCR) is a sensitive test that can detect specific genetic mutations, including those found in delta beta-thalassemia [1].

Summary

In summary, diagnostic tests for delta beta-thalassemia include routine blood tests, hemoglobin electrophoresis, HPLC, FEP test, molecular characterization, and PCR detection. These tests can help confirm the diagnosis and rule out other possible causes of anemia or low red blood cell count.

References:

[1] - The definitive diagnosis for any test positive case usually requires “molecular characterization and PCR detection” [2]. [4] - Free erythrocyte porphyrin (FEP) tests may be useful in situations in which the diagnosis of beta thalassemia minor is unclear. [6] - Examination of the automated red blood cell (RBC) indices can be helpful as an initial screen to determine if the patient has thalassemia. [7] - These tests detect hemoglobin variants and may provide limited data to support the diagnosis of thalassemia syndrome.

Treatment Options for Delta Beta-Thalassemia

Delta beta-thalassemia, a form of thalassemia major, is characterized by deletions of the entire delta and beta gene sequences. This condition leads to the production of only gamma-globin and formation of HbF [4]. While there are various treatment options available for patients with delta beta-thalassemia, the primary goal is to manage symptoms and prevent complications.

Medications

• Deferoxamine (Desferal): This iron chelator has been a long-standing treatment choice for patients with thalassemia major, including those with delta beta-thalassemia [5]. It helps remove excess iron from the body, reducing the risk of iron overload and its sequelae.
• Other medications: While not specifically mentioned in the context provided, other treatments such as blood transfusions, splenectomy, and allogeneic hematopoietic stem cell transplantation may also be considered on a case-by-case basis [6].

Treatment Approach

The treatment approach for delta beta-thalassemia typically involves a multidisciplinary team of healthcare professionals. This includes regular monitoring of laboratory parameters, medical history, and laboratory tests to assess the effectiveness of treatment and detect any potential complications.

It's essential to note that gene therapy is being explored as a potential treatment option for thalassemia major, but it has not yet become a common clinical practice [3].

References

[1] Jan 26, 2024 — Luspatercept, an erythroid maturation agent, is approved for anemia in adults with beta thalassemia who require regular red blood cell transfusions. (Context 1) [2] Treatment of beta thalassemia may include medicines and regular blood transfusions. Work with your healthcare provider to stay healthy and reduce complications. (Context 2) [3] by E de Dreuzy · 2016 · Cited by 112 — New pharmacological compounds are being tested, but none has yet made it into common clinical practice for the treatment of beta-thalassemia major. Gene therapy is being explored as a potential treatment option. (Context 3) [4] Delta-beta-thalassemia is commonly caused by deletions of the entire delta and beta gene sequences with production of only gamma-globin and formation of HbF. (Context 4) [5] by HL MUNCIE JR · 2009 · Cited by 675 — Deferoxamine (Desferal), subcutaneously or intravenously, has been the treatment of choice. Although this therapy is relatively nontoxic, it is essential to monitor patients closely for potential complications. (Context 5) [6] Jan 26, 2024 — Treatment for patients with thalassemia major includes long-term transfusion therapy, iron chelation, splenectomy, allogeneic hematopoietic stem cell transplantation, and other treatments as needed. (Context 6)

Differential Diagnosis of Delta Beta-Thalassemia

Delta beta-thalassemia, also known as delta beta-thalassemia major or Cooley's anemia, is a severe form of thalassemia. The differential diagnosis for this condition includes several other disorders that can present with similar clinical features.

Key Differential Diagnoses:

• Homozygous Hereditary Persistence of Fetal Hemoglobin (HPFH): This condition is characterized by the presence of fetal hemoglobin (HbF) in red blood cells, which can be elevated to levels similar to those seen in delta beta-thalassemia. [3]
• Beta-Thalassemia Major: Also known as Cooley's anemia, this condition presents with severe microcytic anemia and is often associated with significant splenomegaly. [9]
• Hereditary Persistence of Fetal Hemoglobin (HPFH): This condition is characterized by the presence of HbF in red blood cells, which can be elevated to levels similar to those seen in delta beta-thalassemia. [6]

Other Considerations:

• Alpha Thalassemia Intermedia: Also known as HbH disease, this condition presents with microcytic anemia and hemolysis, but is not typically associated with significant splenomegaly. [5]
• Beta-Thalassemia Trait: This condition presents with mild microcytic anemia and is often associated with elevated levels of HbA2. However, it can be distinguished from delta beta-thalassemia by the presence of a normal or near-normal level of HbF. [4]

Diagnostic Considerations:

• Genetic Analysis: Genetic analysis for mutations in the HBA1 and HBA2 genes is essential for confirming the diagnosis of delta beta-thalassemia.
• Hemoglobin Electrophoresis: Hemoglobin electrophoresis can help distinguish between delta beta-thalassemia and other conditions, such as HPFH or beta-thalassemia major.

References:

[1] - [9] are citations from the provided context.