How is Hemoglobin H disease diagnosed?

HbH disease should be considered in infants or children with mild-to-moderate microcytic hypochromic hemolytic anemia and hepatosplenomegaly. Heinz bodies can be detected on blood smears after cresyl blue staining. Hb biochemical analysis reveals the presence of HbH (5-30%). Diagnosis is confirmed by genetic testing.

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What is thalassemia H?

Hemoglobin H disease (HbH) is a form of alpha thalassemia in which moderately severe anemia develops due to reduced formation of alpha globin chains. In this condition, as in the other forms of thalassemia, there is an imbalance of globin chains needed to form hemoglobin.

Which hemoglobin is present in thalassemia?

Mutations in the HBB gene cause beta thalassemia. The HBB gene provides instructions for making a protein called beta-globin. Beta-globin is a component (subunit) of hemoglobin . Hemoglobin consists of four protein subunits, typically two subunits of beta-globin and two subunits of another protein called alpha-globin.

Is Hemoglobin H disease thalassemia major?

Hemoglobin H disease. This type causes moderate to severe symptoms. These include lack of energy (fatigue) and exercise intolerance. You may also have an enlarged liver or spleen, yellowish skin, and leg ulcers. You have a greater risk of having a child with the most severe type, alpha thalassemia major.

Why does thalassemia cause hemolysis?

The thalassemias (named from the Greek word for sea, thalassa1) are a group of inherited autosomal recessive hematologic disorders2 that cause hemolytic anemia because of the decreased or absent synthesis of a globin chain. Imbalances of globin chains cause hemolysis and impair erythropoiesis.

What causes hemoglobin H?

Hemoglobin H forms when only one normal alpha gene has been inherited. This causes significantly impaired alpha globin production. In the neonatal period, this will cause an excess of gamma, and in adults, this leaves an excess of beta-globin chains. Free alpha chains are insoluble.

What is Hemoglobin H made of?

In a normal adult, the major hemoglobin is Hb A (α2β2). The α-globin gene cluster is located on chromosome 16pter-p13. 3 and is made up of one embryonic ζ-globin and 2 α-globin genes in tandem (in cis): 5′-ζ2-α2-α1-3′. 1 Because each person has 2 chromosomes 16, most people have 4 α-globin genes.

What does a CBC look like with thalassemia?

With beta thalassemia, a CBC is done to measure the amount of hemoglobin and the number and the size and shape of red blood cells, which are fewer in number and smaller in size than in normal individuals. Red blood cells may also be pale in color (hypochromic) and of varying shapes.

How is thalassemia diagnosed?

Doctors diagnose thalassemias using blood tests, including a complete blood count (CBC) and special hemoglobin tests. A CBC measures the amount of hemoglobin and the different kinds of blood cells, such as red blood cells, in a sample of blood.

What is the difference between alpha thalassemia and HBH?

What is hemoglobin H disease (HBH)?

By Ashutosh Lal, MD Hemoglobin H disease (HbH) is a form of alpha thalassemia in which moderately severe anemia develops due to reduced formation of alpha globin chains. In this condition, as in the other forms of thalassemia, there is an imbalance of globin chains needed to form hemoglobin.

What is thalassemia?

What is thalassemia? Hemoglobin H disease also known as Alpha thalassemia intermedia that is caused by deletion of three alpha-globin genes (only one normal alpha gene has been inherited) 1). Hemoglobin H disease is named for the abnormal hemoglobin H (created by the remaining beta globin) that destroys red blood cells.

How does alpha thalassemia affect the body?

Affected people have anemia, which can cause pale skin, weakness, fatigue, and more serious complications. Two types of alpha-thalassemia can cause health problems: the more severe type is known as hemoglobin Bart syndrome (Alpha Thalassemia Major or Hemoglobin Bart’s Hydrops Fetalis); the milder form is called hemoglobin H disease (HbH disease).