Which pairing correctly describes the relative severity of the major thalassemia type?

Which pairing correctly describes the relative severity of the major thalassemia type?

• A. Alpha thalassemia major - most severe
• B. Beta thalassemia minor - most severe
• C. Alpha thalassemia minor - most severe
• D. Beta thalassemia major - most severe

Answer: (A)

When severity is ranked among thalassemia types, the form that results from losing all alpha-globin production is the most dire. Deleting all four alpha-globin genes leads to Hb Bart hydrops fetalis, a condition so severe that it is typically fatal before or shortly after birth because the fetus cannot make enough functional hemoglobin. That makes alpha thalassemia major the most severe among thalassemias. Beta thalassemia major is also very serious and requires regular transfusions, but with medical care individuals can survive into adulthood, so it is not as universally fatal as Hb Bart hydrops fetalis. The minor forms, whether alpha or beta, usually cause little to no symptoms, so they are not considered the severe end of the spectrum.

When severity is ranked among thalassemia types, the form that results from losing all alpha-globin production is the most dire. Deleting all four alpha-globin genes leads to Hb Bart hydrops fetalis, a condition so severe that it is typically fatal before or shortly after birth because the fetus cannot make enough functional hemoglobin. That makes alpha thalassemia major the most severe among thalassemias.

Beta thalassemia major is also very serious and requires regular transfusions, but with medical care individuals can survive into adulthood, so it is not as universally fatal as Hb Bart hydrops fetalis. The minor forms, whether alpha or beta, usually cause little to no symptoms, so they are not considered the severe end of the spectrum.