Heme molecules are necessary for red blood cells to pick up oxygen in the lungs and deliver it to the body’s tissues. A complete hemoglobin protein is capable of carrying four oxygen molecules at a time (one attached to each heme molecule). Oxygen attached to hemoglobin gives blood its bright red color.
What is the function of B globin?
The beta globin protein is one of the subunits of hemoglobin, a protein necessary for the oxygen-carrying function of red blood cells. People with the sickle cell mutation in both copies of the HBB gene produce proteins that clump together and lead to changes in the shape and behavior of red blood cells.
What is HbA in blood?
Hemoglobin A (HbA), also known as adult hemoglobin, hemoglobin A1 or α2β2, is the most common human hemoglobin tetramer, accounting for over 97% of the total red blood cell hemoglobin. Hemoglobin is an oxygen-binding protein, found in erythrocytes, which transports oxygen from the lungs to the tissues.
What does the HbS gene do?
The HBB gene provides instructions for making beta-globin. Various versions of beta-globin result from different mutations in the HBB gene. One particular HBB gene mutation produces an abnormal version of beta-globin known as hemoglobin S (HbS).
Is HbA normal?
Normal Results HbA: 95% to 98% (0.95 to 0.98) HbA2: 2% to 3% (0.02 to 0.03)
What is HBA1 and 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.
How does HbS protein function differently than HbA protein in RBC?
This causes the body to produce a new form of haemoglobin called HbS, which behaves very differently to regular haemoglobin (HbA). HbS causes the red blood cells to develop abnormally and become sickle-shaped (rather than the usual doughnut shape), harder and less flexible.
What is normal HBA?
Normal Results HbA: 95% to 98% (0.95 to 0.98) HbA2: 2% to 3% (0.02 to 0.03) HbE: Absent. HbF: 0.8% to 2% (0.008 to 0.02) HbS: Absent.
How does HbS cause sickling?
Desaturation of HbS results in the polymeriz- ation of haemoglobin, forming large aggregates called tactoids, which deform the red cells into the typical sickle shape.
What is HbS in anemia?
In a routine blood test, anemia is reported as a low hemoglobin or hematocrit. Hemoglobin is the main protein in your red blood cells. It carries oxygen, and delivers it throughout your body. If you have anemia, your hemoglobin level will be low too.
