<unk>  <unk> assemia,<unk> assaemia) is a form of<unk> assemia involving the genes HBA1 and HBA2.<unk> assemias are a group of inherited blood conditions which result in the impaired production of hemoglobin, the molecule that carries oxygen in the blood. Normal hemoglobin consists of two<unk>  chains and two beta chains; in<unk> , there is a quantitative decrease in the amount of<unk>  chains, resulting in fewer normal hemoglobin molecules. Furthermore,<unk>  leads to the production of unstable beta globin molecules which cause increased red blood cell destruction. The degree of impairment is based on which clinical phenotype is present (how many genes are affected).
Alpha-thalassemia
Thalassemia
Beta thalassemia
Delta-beta thalassemia
Hereditary spherocytosis
Hemoglobinemia
Paroxysmal nocturnal hemoglobinuria
Sideroblastic anemia