ALPHA, BETA, AND TRANSFUSION STATUS

While alpha-thalassemia and beta-thalassemia refer to genetics and inheritance pattern, there are many ways to describe thalassemia.

Alpha-thalassemia means there are changes in 1 or more alpha-globin genes.

• 4 genes provide instructions for making alpha-globin:
  • In alpha-thalassemia major, all 4 alpha-globin genes are affected
  • In alpha-thalassemia intermedia, 3 out of 4 alpha-globin genes are affected
  • In alpha-thalassemia trait, 1 or 2 out of 4 alpha-globin genes are affected; if only 1 alpha-globin gene is affected, a patient is sometimes called a “silent carrier”

*Hb=hemoglobin.

Beta-thalassemia means there are changes in 1 or more beta-globin genes.

• 2 genes provide instructions for making beta-globin:
  • In beta-thalassemia major and beta-thalassemia intermedia, both beta-globin genes are affected
  • In beta-thalassemia minor, only 1 beta-globin gene is affected

Talk with your doctor or a genetic counselor for more details about testing for thalassemia type, education about inheritance patterns, and more personalized information.

Thalassemia major, thalassemia intermedia, thalassemia minor, and thalassemia trait refer to genetics and severity of anemia.

More recently, experts have begun to describe thalassemia based on transfusion status: transfusion-dependent thalassemia (TDT) and non–transfusion-dependent thalassemia (NTDT).

• Thalassemia that requires regular blood transfusions for survival may be referred to as TDT. For example, a person living with beta-thalassemia who receives transfusions every 3 weeks may be considered to have TDT
• Thalassemia that does not require blood transfusions for survival may be referred to as NTDT
• Those who have NTDT may receive transfusions from time to time or not at all
• People with NTDT may require more frequent transfusions over time, which could lead to TDT

While there are many ways to describe thalassemia, NTDT and TDT share in common the body’s inability to produce adequate amounts of hemoglobin and healthy red blood cells.