Normal Results HbA2: 2% to 3% (0.02 to 0.03)

What does it mean if hemoglobin A2 is low?

Low Hb A2 percentages were found in iron-deficiency anemia, hereditary persistance of fetal hemoglobin, and Hb H disease. In iron-deficiency anemia, the lowest levels of Hb A2 were observed in association with the most severe anemia.

What does high HbA2 mean?

Hb A2 is increased in beta thalassemia because the relative lack of beta globin allows more delta chains to be incorporated into hemoglobin. Beta thalassemia is caused by mutations in the beta globin gene locus on chromosome 11.

What is HB A2 test?

A proposed test for confirming the diagnosis of iron deficiency.

What does high Hemoglobin A2 mean?

Hemoglobin A2 may be increased in beta thalassemia or in people who are heterozygous for the beta thalassemia gene. HbA2 exists in small amounts in all adult humans (1.5-3.1% of all hemoglobin molecules) and is approximately normal in people with sickle-cell disease.

What is the purpose of HbA2?

Normal Function The HBA2 gene provides instructions for making a protein called alpha-globin. This protein is also produced from a nearly identical gene called HBA1. These two alpha-globin genes are located close together in a region of chromosome 16 known as the alpha-globin locus.

What is the difference between HbA and HbA2?

Adult hemoglobin A (HbA) has two alpha and two beta chains (alpha2 beta2), whereas hemoglobin A2 (HbA2) has two alpha and two delta chains (alpha2 delta2).

What are the 3 types of hemoglobin?

The most common are:

What is hemoglobin A1 and A2?

In adults, more than 90 percent have type A1 hemoglobin, containing two a and two beta (b) globin chains. A small amount carry a variant called hemoglobin A2, having two a and two delta (d) chains. Infants are born with a slightly different type called fetal hemoglobin, with two a chains and two gamma (g) chains.

Can all abnormal hemoglobins be diagnosed by electrophoresis?

Patients should be screened with a hemoglobin electrophoresis which is able to detect not only the abnormal hemoglobin S of sickle cell anemia, but also other abnormal hemoglobin variants which may cause disease.

What is the most common Hemoglobinopathy?

Sickle cell disease, the most common hemoglobinopathy, occurs when at least one HbS variant is present with a second pathogenic beta globin variant; the variants result in abnormal Hb. For more information on pathogenic Hb variants, see the Human Hemoglobin Variants and Thalassemias database.

What is a Hemoglobinopathy?

The hemoglobinopathies are a group of disorders passed down through families (inherited) in which there is abnormal production or structure of the hemoglobin molecule. Sickle cell disease (SCD) is one such blood disorder caused by the abnormal hemoglobin that damages and deforms red blood cells.

What is HbA2 thalassemia?

The increase in hemoglobin A2 (HbA2) level is the most significant parameter in the identification of β-thalassemia carriers.

What is alpha thalassemia hba1 HbA2?

Alpha-thalassemia is an autosomal recessive condition that affects the red blood cells. It can affect people of any ethnicity, but is more common in people who can trace their ancestry to Southeast Asia, India, equatorial Africa, the Mediterranean, or the Arabian Peninsula.

What happens if HbF is high?

A baby growing in the womb has high levels of HbF. The level of HbF usually drops to tiny amounts about 6 months after birth. In an adult or child, a higher level of HbF can mean you have a blood disorder. These include thalassemia, myeloid leukemia, and sickle cell anemia.

What makes up hba2?

Protein. Two alpha chains plus two beta chains constitute HbA, which in normal adult life comprises about 97% of the total hemoglobin; alpha chains combine with delta chains to constitute HbA-2, which with HbF (fetal hemoglobin) makes up the remaining 3% of adult hemoglobin.

What are the chains of hba2?

HbA is constituted from two alpha chains and two beta chains which in standard adult life hold about 97% of the total hemoglobin; alpha chains associate with delta chains to create HbA-2 that with HbF (fetal hemoglobin) form the remaining 3% of adult hemoglobin.

Does thalassemia trait cause anemia?

Thalassemia (thal-uh-SEE-me-uh) is an inherited blood disorder that causes your body to have less hemoglobin than normal. Hemoglobin enables red blood cells to carry oxygen. Thalassemia can cause anemia, leaving you fatigued.

When is HbS less soluble than HbA?

This single mutation leads to the formation of abnormal hemoglobin, HbS (alpha2betas[s]2), which is much less soluble when deoxygenated than hemoglobin A (HbA) (alpha2beta2).

What are the 4 types of alpha thalassemia?

There are 4 types of alpha thalassemia:

Why is RBC count high in thalassemia?

In the case of β-thalassemia, which is due to defective production of the β-globin chain of hemoglobin, the free α-globin chains precipitate in erythroid precursors causing anemia primarily due to impaired production of red blood cells.

What is the charge of HbS?

In the case of Sickle Cell hemoglobin [right], replacement of a negatively-charged Glu in the standard HbA beta-globin by a neutral Val in HbS results in a protein with a slightly reduced negative charge.

What are the 4 types of Haemoglobin?

Four different hemoglobin species are commonly recognized: oxyhemoglobin (oxy-Hb), deoxyhemoglobin (deoxy-Hb), methemoglobin (met-Hb), and hemichromes, whose structures appear below.

What are the seven types of hemoglobin?

Embryonic Haemoglobin: