What is the Difference Between G6PD and Sickle Cell

The key difference between G6PD and sickle cell is that G6PD (glucose 6 phosphate dehydrogenase) is an enzyme that protects red blood cells from haemolysis while the sickle cell is an abnormal shape of red blood cell that causes the haemolysis of red blood cells.

Haemolytic anaemia is a blood disorder. In this condition, red blood cells are destroyed faster than they are synthesized. Haemolysis refers to the destruction of red blood cells. The function of red blood cells is to carry oxygen through the body. Therefore, if people have low red blood cells levels, they tend to suffer from anaemia. This anaemia condition can be inherited or acquired. Therefore, G6PD and sickle cell are two terms related to haemolysis.

CONTENTS

1. Overview and Key Difference
2. What is G6PD 
3. What is Sickle Cell
4. Similarities – G6PD and Sickle Cell
5. G6PD vs Sickle Cell in Tabular Form
6. Summary

What is G6PD?

G6PD (glucose 6 phosphate dehydrogenase) is an enzyme that protects red blood cells from haemolysis. G6PD is widely distributed in many species, like bacteria to humans.  This enzyme is generally a dimer that consists of two identical monomers. Glucose 6 phosphate is the substrate that stimulates glucose 6 phosphate dehydrogenase.

This enzyme participates in the pentose phosphate metabolic pathway that supplies reducing energy to cells. The normal function of this enzyme is reducing NADP to NADPH while oxidizing glucose 6 phosphate. The NADPH maintains a level of glutathione in red blood cells. Glutathione protects cells against oxidative damage from compounds like hydrogen peroxide. Therefore, normally X linked genetic deficiency of G6PD causes non-immune haemolytic anaemia in humans.

Figure 01: G6PD

G6PD enzyme deficiency mainly affects males. Glucose 6 phosphate dehydrogenase deficiencies may typically cause anaemic symptoms such as paleness, yellowing in skin and whites of the eyes, dark urine, fatigue, shortness of breath and rapid heart rate. Furthermore, people with glucose 6 phosphate dehydrogenase deficiency can have haemolytic anaemia due to simple infection, ingestion of fava beans or consuming certain medication like antibiotics, antipyretics, or antimalarials. The treatment for this genetic condition consists of removing the trigger that causes normal symptoms. Blood transfusions can also be done for anaemia. However, many people with this genetic disorder never experience any signs or symptoms and generally are unaware of this condition.

What is Sickle Cell?

Sickle cell is an abnormal shape of red blood cells that causes haemolysis of red blood cells. Sickle cell disease is a group of inherited red blood cells disorder. In this condition, people won’t have enough healthy red blood cells to carry oxygen throughout the body. Sickle cell disease typically follows the autosomal recessive inheritance pattern. Haemoglobin is the protein inside the red blood cells. Haemoglobin consists of four subunits: two alpha globin subunits and two beta globin subunits.

Figure 02: Sickle Cell

In sickle cell disease, a mutation in the HBB gene that forms beta globin subunits of haemoglobin changes the shape of red blood cells from biconcave to a sickle shape. This common mutation is a single nucleotide substitution that replaces the amino acid in 6th position beta globin protein from glutamine to valine. Therefore, sickle cell disease triggers haemolysis and causes anaemia in patients. The typical symptoms of sickle cell disease are anaemia, episodes of pain, frequents infections, delayed growth, vision problems, yellow tint in skin etc. Moreover, the treatment for this condition is normally blood transfusions. But bone marrow transplantation is a permanent solution.

What are the Similarities Between G6PD and Sickle Cell?

  1. G6PD and sickle cell are two terms related to haemolysis.
  2. Both are important concerns in patients with haemolytic anaemia.
  3. They are helpful factors to determine the normal function of red blood cells.
  4. They are both associated with diseases.

What is the Difference Between G6PD and Sickle Cell?

G6PD is an enzyme that protects red blood cells from haemolysis while the sickle cell is an abnormal shaped red blood cell that causes haemolysis of red blood cells. So, this is the key difference between G6PD and sickle cell. Furthermore, G6PD deficiency causes haemolytic anaemia, while a surplus of the sickle cell causes haemolytic anaemia.

The below infographic lists the differences between G6PD and sickle cell in tabular form for side by side comparison.

Summary – G6PD vs Sickle Cell

In a recent research study, it was identified that patients with sickle cell disease (SCD) are more prone to haemolysis due to the shape of red blood cells and if they are deficient in G6PD enzyme. G6PD is an enzyme that protects red blood cells from haemolysis. The key difference between G6PD and sickle cell is that G6PD is an enzyme that protects red blood cells from haemolysis while sickle cell is an abnormal shape of red blood cells that causes the haemolysis of red blood cells.