What is 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). At birth, HbF accounts for approximately 80 percent of hemoglobin and HbA accounts for 20 percent.
What does it mean if HbA2 is high?
Other causes of elevated HbA2 other than thalassemia include antiretroviral therapy, vitamin B12/folate deficiency, and hyperthyroidism. Hemoglobin electrophoresis and high-performance liquid chromatography can also elucidate other hemoglobinopathies complicating a beta-thalassemia trait.
What is alpha and beta chain in hemoglobin?
The normal hemoglobin (Hb A) in adults contains two α chains and two β chains. Each α chain contains 141 amino acids, and each β chain contains 146 amino acids. Hb A2 contains two α chains and two δ chains.
What does Hemoglobin A2 do?
Red blood cell hemoglobin is used to transport oxygen from the lungs to the tissues. Normal adult hemoglobin contains 95% to 98% hemoglobin A (two alpha chains and two beta chains).
What is HbA and HbF?
HbF is produced by erythroid precursor cells from 10 to 12 weeks of pregnancy through the first six months of postnatal life. HbF contains two alpha and two gamma subunits, while the major form of adult hemoglobin, hemoglobin A (HbA), contains two alpha and two beta subunits.
Does everyone have HbA2?
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. Its biological importance is not yet known.
What is the most common cause of IDA?
Iron deficiency anemia results from low or depleted stores of iron, which is needed to produce red blood cells. Excessive bleeding is the most common cause.
Is HbA normal?
Normal Results HbA: 95% to 98% (0.95 to 0.98) HbA2: 2% to 3% (0.02 to 0.03)
Is HbA same as HbF?
HbF is an α2γ2 tetramer and while having exactly the same α-chains as adult hemoglobin (HbA), HbF has, by contrast, two gamma (γ) polypeptide subunits that are highly homologous to the HbA β-chains but with significant structural differences as outlined in the table below.
What is hemoglobin alpha 2?
Hemoglobin, alpha 2 also known as HBA2 is a gene that in humans codes for the alpha globin chain of hemoglobin.
Which is the gene that codes for hemoglobin A2?
This article is about a gene. For the similarly named Hemoglobin tetramer, HbA2, see Hemoglobin A2. Hemoglobin, alpha 2 also known as HBA2 is a gene that in humans codes for the alpha globin chain of hemoglobin.
What is the name of the non alpha chain in hemoglobin?
The fetus has a distinct non-alpha chain called gamma. After birth, a different non-alpha globin chain, called beta, pairs with the alpha chain. The combination of two alpha chains and two non-alpha chains produces a complete hemoglobin molecule (a total of four chains per molecule).
What makes up 97% of adult hemoglobin?
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. Clinical significance