Hemoglobin H

see thalassemias


Form of α-thalassemia with 3 defective genes causing a clinical picture of severe thalassemia. Hemoglobin H is formed by tetramers of chains β and is very unstable (hemolysis). 

In the fetus, the accumulation of chains γ causes their tetramerisation to form hemoglobin Bart, the concentration of which is  then higher than normal