An 18-year-old woman has a low hemoglobin value of 10.5 g/dL on routine CBC testing. The red cells are microcytic, but the WBC and platelet counts are normal. She has an adequate intake of iron-containing foods, her menstrual flow is normal, and there is no other history of blood loss. Her physical examination is completely normal, and iron studies reveal a normal ferritin level. She states that other members in her family have also been told they are anemic and given a diagnosis of alpha-thalassemia. Formation of which of the following hemoglobin's is increased in alpha-thalassemia?
Alpha-thalassemia involves a decrease in alpha-chain production and leads to the formation of beta-globin tetramers known as hemoglobin H. Individuals normally inherit four alpha-chain genes. The clinical syndrome depends on how many genes are deleted. Deletion of 1 gene results in a silent carrier state. Deletion of all 4 is the most severe and presents as hydrops fetalis. This condition is incompatible with life.
H
A
F
A2
Blood