hemoglobin D disease

Hemoglobin D Disease (HbD): A Rare Hemoglobinopathy

Hemoglobin D disease, also known as HbD, is a rare inherited disorder characterized by the production of abnormal variant hemoglobin known as hemoglobin D. This condition affects the hemoglobin in red blood cells, leading to mild clinical manifestations.

Key Features:

• Production of Abnormal Hemoglobin: Individuals with HbD disease produce only hemoglobin D, with no or minimal production of normal adult hemoglobin (HbA).
• Mild Clinical Manifestations: The condition is typically associated with mild symptoms, including:
  • Mild anemia
  • Splenomegaly (enlarged spleen)
  • No significant pain episodes or organ damage
• Inheritance Pattern: HbD disease is inherited as a recessive genetic disorder, meaning that an individual must inherit two copies of the mutated gene (one from each parent) to express the condition.

Prevalence and Demographics:

Hemoglobin D disease is relatively rare and most commonly found in individuals from East India. The condition can be passed on to children if both parents are carriers of the mutated gene.

References:

• [1] Definition Hemoglobin D is an inherited variant of hemoglobin A.
• [3] Disease definition. Hemoglobin D disease(HbD) is a hemoglobinopathy characterized by production of abnormal variant hemoglobin known as hemoglobin D, with no or mild clinical manifestations (splenomegaly, very mild anemia).
• [4] Hemoglobin D trait is a change (mutation) in a gene that helps make hemoglobin in red blood cells.
• [13] Definition. Hemoglobin D disease(HbD) is a hemoglobinopathy characterized by production of abnormal variant hemoglobin known as hemoglobin D, with no or mild clinical manifestations ...
• [14] Hemoglobin D disease(HbD) is a hemoglobinopathy characterized by production of abnormal variant hemoglobin known as hemoglobin D, with no or mild clinical manifestations (splenomegaly, very mild anemia).
• [15] Hemoglobin D disease(HbD) is a hemoglobinopathy characterized by production of abnormal variant hemoglobin known as hemoglobin D, with no or mild clinical manifestations (splenomegaly, very mild anemia).

Mild Hemolytic Anemia in Infants

Individuals with hemoglobin D disease typically develop a mild hemolytic anemia in the first few months of life, as fetal hemoglobin decreases and hemoglobin D increases [1]. This is because their red blood cells contain mostly hemoglobin D, which can reduce the number and size of red blood cells.

No Symptoms in Most Cases

Most people with hemoglobin D trait have no signs or symptoms of illness. The trait normally does not cause any health problems [2]. However, individuals with hemoglobin D disease may experience some mild clinical manifestations, such as splenomegaly (enlarged spleen) and very mild anemia [3].

Possible Symptoms in Some Cases

In some cases, symptoms of hemoglobin D disease may start to appear during childhood. These can include:

• Mild anemia
• Splenomegaly
• Other complications related to the disease

It's worth noting that the severity of these symptoms can vary from person to person.

References:

[1] Individuals with hemoglobin D disease do not produce hemoglobin A; they only produce hemoglobin D. Clinical Symptoms A mild hemolytic anemia develops in the first few months of life as fetal hemoglobin decreases and hemoglobin D increases. [2] Most people with hemoglobin D trait have no signs or symptoms of illness. The trait normally does not cause any health problems. [3] Hemoglobin D disease(HbD) is a hemoglobinopathy characterized by production of abnormal variant hemoglobin known as hemoglobin D, with no or mild clinical manifestations (splenomegaly, very mild anemia).

Diagnostic Tests for Hemoglobin D Disease

Hemoglobin D disease can be diagnosed through various blood tests that detect abnormal forms of hemoglobin in the blood. Here are some of the diagnostic tests used to confirm the presence of hemoglobin D disease:

• Hemoglobin Electrophoresis: This is a simple blood test that separates and identifies different types of hemoglobin in the blood. It can detect the presence of hemoglobin D and other abnormal forms of hemoglobin [7].
• Blood Tests for Parents: If one or both parents are suspected to have hemoglobin D trait, they should undergo blood tests to confirm the diagnosis. This is essential to rule out hemoglobin D thalassemia disease in subsequent children [1].
• Newborn Screening: A simple blood test can detect hemoglobin D trait in newborns as part of routine screening programs [2, 4].

These diagnostic tests are crucial for confirming the presence of hemoglobin D disease and ruling out other conditions that may be associated with abnormal forms of hemoglobin.

References:

[1] Confirm diagnosis with infant blood tests and test the parents to rule out hemoglobin D thalassemia disease. [2] A simple blood test can let you know if you have hemoglobin D trait. These tests are often done as part of routine newborn screening. [4] A simple blood test called a hemoglobin electrophoresis can tell if your baby has hemoglobin D trait. [7] Hemoglobin electrophoresis is a test that measures the different types of hemoglobin in the blood. It also checks for hemoglobinopathy, disorders involving abnormal forms of hemoglobin.

Treatment Options for Hemoglobin D Disease

Hemoglobin D disease, also known as HbD disease, is a rare genetic disorder that affects the production of hemoglobin in red blood cells. While there are no specific treatments available to cure the disease, various medications and therapies can help manage its symptoms.

• No treatment required: In most cases, hemoglobin D disease does not require any treatment, as it typically causes mild or no symptoms (1). However, if the disease is inherited with other conditions, such as beta thalassemia, treatment may be necessary to manage more severe symptoms (5).
• Supportive care: Patients with hemoglobin D disease may need supportive care, including blood transfusions and iron supplements, to manage mild anemia and other complications (4).
• Pain management: Some patients may experience pain episodes, which can be managed with pain medications such as acetaminophen or ibuprofen (13).

Newer Treatment Options

Recent studies have investigated the use of newer treatments for hemoglobinopathies, including voxelotor, a medication that has shown promise in improving anemia and reducing transfusion requirements in patients with sickle cell disease (14). However, it is essential to note that these treatments are not specifically approved for hemoglobin D disease.

References

• [1] Hemoglobin D disease is typically inherited as a recessive genetic disorder, meaning a person must inherit two copies of the mutated gene (one from each parent) to develop the disease.
• [4] Hb DD disease - People with this condition inherit Hb D from both parents and may experience small red blood cells, mild anemia, and a large spleen.
• [5] Hemoglobin D disease is not a form of sickle cell disease and usually does not cause serious health problems; however, if inherited with other conditions, treatment may be necessary to manage more severe symptoms.
• [13] Although a form of sickle cell disease, most individuals with hemoglobin sickle D disease have fewer problems with infections and spleen involvement, fewer pain episodes, and less organ damage than the other more common forms of sickle cell disease.
• [14] Voxelotor Treatment Interferes With Quantitative and Qualitative Hemoglobin Variant Analysis in Multiple Sickle Cell Disease Genotypes.

Differential Diagnosis of Hemoglobin D Disease

Hemoglobin D disease, also known as Hb D disease, is a rare genetic disorder characterized by the production of abnormal variant hemoglobin known as hemoglobin D. The differential diagnosis of this condition involves considering other possible causes of similar symptoms and laboratory findings.

Possible Differential Diagnoses:

• Beta Thalassemia: This is another type of hemoglobinopathy that can cause mild to severe anemia, depending on the severity of the mutation.
  • [5] states that "The diagnosis of HbSC disease is made with Hb electrophoresis. The peripheral blood smear may have some sickled cells and a high proportion of target cells."
• Hemoglobin C Disease: This condition can also cause mild to severe anemia, and the laboratory findings may be similar to those seen in hemoglobin D disease.
  • [7] lists "Hemoglobin C Disease" as one of the differential diagnoses for acute anemia.
• Chronic Anemia: Any underlying chronic condition that affects the production or destruction of red blood cells can lead to symptoms similar to those seen in hemoglobin D disease.
  • [10] states that "Symptoms may begin in a single age range, or during several age ranges. The symptoms of some diseases may begin at any age."
• Hemolytic Anemia: This condition is characterized by the premature destruction of red blood cells, which can lead to similar laboratory findings as hemoglobin D disease.
  • [2] states that "Tests indicative of hemolysis include decreased or absent haptoglobin, elevated LDH and unconjugated bilirubin, and elevated serum free hemoglobin."

Key Points:

• A comprehensive medical history and physical examination are essential to rule out other possible causes of similar symptoms.
• Laboratory tests such as Hb electrophoresis, peripheral blood smear, and measurement of haptoglobin, LDH, and unconjugated bilirubin can help confirm the diagnosis of hemoglobin D disease.
• In complex cases, coordinating with a network of experts may be necessary to find the right diagnosis.

References:

[2] Jan 17, 2019 — Tests indicative of hemolysis include decreased or absent haptoglobin, elevated LDH and unconjugated bilirubin, and elevated serum free hemoglobin. [5] Sep 25, 2024 — The diagnosis of HbSC disease is made with Hb electrophoresis. The peripheral blood smear may have some sickled cells and a high proportion of target cells. [7] Jun 27, 2024 — Hemoglobin variants including Hb C, Hb D, and Hb E; Hemoglobinopathy: Screening and counseling in the reproductive setting and fetal diagnosis. [10] Hemoglobin D disease(HbD) is a hemoglobinopathy characterized by production of abnormal variant hemoglobin known as hemoglobin D, with no or mild clinical.