Difference between Sickle Cell Anemia and Sickle Cell Disease

Know the Difference Between Sickle Cell Anemia and Sickle Cell Disease

Over 100,000 of the U.S. population and 8 million of the global population live with sickle cell disease, including sickle cell anemia.

Sickle cell disease (SCD) is a collective term for various genetic blood disorders, including sickle cell anemia. These inherited disorders distort the red blood cells into a sickle shape, hence the name of the disease. In these disorders, a protein of the red blood cells, called hemoglobin, is rendered abnormal (HbS) due to genetic mutations.

SCD treatment options such as hematopoietic stem cell transplant (HSCT) for eligible patients, and gene therapy (e.g., CRISPR-Cas9) is emerging. 

Contrary to popular belief, sickle cell disease and sickle cell anemia are not separate conditions. Sickle cell anemia is a severe and chronic type of SCD.

Read ahead for a more comprehensive idea of sickle cell disease, sickle cell anemia, and their differences.

What is Sickle Cell Disease?

Sickle cell disease is a broad term for genetic blood disorders in which the red blood cell protein called hemoglobin becomes faulty due to a mutation in the hemoglobin gene. This abnormal hemoglobin is called hemoglobin S.

In sickle cell disease, both the shape and function of red blood cells are altered in the following ways:

• Under healthy circumstances, red blood cells have normal hemoglobin or Hb, giving them a circular shape.

• Genetic mutations in the hemoglobin gene render an abnormal hemoglobin that distorts the red blood cells to become half-mooned or sickle-shaped. This abnormal hemoglobin is called HbS.

• Healthy red blood cells are smooth and flexible, easily moving through the blood vessels to supply oxygen to different body parts, including cells, tissues, and organs.

• Due to the inherited abnormal hemoglobin S, the crescent-shaped red blood cells turn stiff and stick together, hampering blood flow and leading to much lower blood flow to various body parts. This may lead to serious side effects such as sudden pain flares, organ failure, infections, and stroke, to name a few.

• The sickle-shaped red blood cells have a much shorter life span than healthy red blood cells and die sooner. This causes a constant dearth of red blood cells, leading to anemia.

What are the types of Sickle Cell Diseases?

Yes. There are various types of SCD. Each type is classified based on inherited genes from parents to children. Every kind of SCD necessarily inherits a gene that codes for faulty hemoglobin or HbS.

The main types of sickle cell disease are :

Hemoglobin SS (Sickle Cell Anemia)

• In this type of SCD, one gene that codes for HbS is inherited from the first parent, and another gene that also codes for HbS is inherited from the second parent. Hence, the child's genotype is HbSS.

• HbS distorts red blood cells, making them rigid, sickle-shaped, and prone to clumping. In low oxygen conditions, blood flow to various parts of the body is obstructed, and red blood cells are continually lost because sickle cells don’t live as long as healthy ones.

• Since almost all the hemoglobin is abnormal in this form of SCD, it leads to severe and chronic anemia, including symptoms of weakness and chronic fatigue.

• Hence, sickle cell anemia is a severe sickle cell disease with the genotype HbSS.

Other notable types of sickle cell disease include:

Hemoglobin SC or HbSC

In this type of SCD, one gene that codes for HbS is acquired from the first parent, and another gene that codes for another abnormal type of hemoglobin, HbC, is inherited from the second parent. Hence, the child's genotype becomes HbSC. This subtype of SCD is a mild to moderate form.

Hemoglobin (HbS) beta thalassemia

In this type of SCD, one gene that codes for HbS is acquired from the first parent. Another gene that codes for another abnormal type of hemoglobin, beta thalassemia, is inherited from the second parent. Thus, the genotype obtained is HbS beta thalassemia.

This form of SCD can be of mild or extreme severity.

Other uncommon and lesser-known genotypes of abnormal hemoglobin include:

• Genotype HbSD or hemoglobin SD ( one HbS gene from the first parent and another abnormal HbD gene from the second parent )

• Genotype HbSO or hemoglobin SO ( one HbS gene from the first parent and another abnormal HbO gene from the second parent)

• Genotype HbSE or hemoglobin SE (one HbS gene from the first parent and another abnormal HbE gene from the second parent)

Though sickle cell disease, including sickle cell anemia, is a chronic illness, early diagnosis and proper care can help manage symptoms and reduce further complications.

Consult a qualified healthcare provider for a customized treatment plan that fits your needs.

Contact Star Health Insurance to ensure quality treatment and financial assistance. Our  Special Care Gold, Star Health and Allied Insurance Company Limited plan covers genetic disorders like sickle cell disease.

Call now for further assistance!