Sickle Cell Trait vs. Thalassemia Trait: Understanding the Differences

Sickle cell anemia and thalassemia are two distinct hereditary red blood cell disorders. Each of these diseases has its own traits, which are passed down from generation to generation.

The Facts

• In sickle cell anemia, inherited genetic changes cause red blood cells to form an abnormal sickle shape, according to the Nemours Foundation. In thalassemia, genetic changes cause diminished or defective production of the red blood cell component hemoglobin.

Sickle Cell Trait

• Sickle cell trait occurs when an individual inherits a sickle cell gene from one parent and a normal gene from the other, reports the Nemours Foundation.

Thalassemia Forms

• Hemoglobin has two constituent proteins, alpha globin and beta globin, according to the U.S. National Library of Medicine. Thalassemia occurs in two main forms -- alpha thalassemia and beta thalassemia -- which correspond to the hemoglobin protein affected.

Thalassemia Traits

• Individuals can carry either alpha or beta thalassemia trait, notes the Nemours Foundation. Alpha-thalassemia trait results from genetic changes to one or two of the four alpha globin genes, while beta-thalassemia trait results from changes to one of the two beta globin genes.

Effects

• Individuals with sickle cell trait typically have no symptoms, reports the Nemours Foundation. Individuals with either thalassemia trait may experience mild anemia (insufficient healthy red blood cells).