thalassemia

August 12, 2017 17:51 | Genetic Diseases

Thalassemia - a group of diseases with hereditary protein synthesis violation globin, a component of hemoglobin.Globin consists of several amino acid chains, namely 2-a and 2-in-chains.In thalassemia may be a violation of the synthesis of any of these circuits.Streets with the disease occurs severe or slight anemia, and serum iron content is normal or increased.

thalassemia first was described in 1925 by US pediatricians.They observed 5 children who were found signs of severe anemia, a significant enlargement of the spleen and liver, bone changes.Following the publication of their reports it published a work by Italian authors, who described a similar, but much more mild form of the disease, in which people lived to adulthood and had children.The term "thalassemia" was proposed in 1936 for the first time the idea that thalassemia is a result of the synthesis of protein chains globin disorders, several scientists expressed independently.Thalassemia, in which the synthesis is disturbed β-globin chain, cal

led β-thalassemia.In α-thalassemia impaired protein synthesis α-chain.More common β-thalassemia.In thalassemia

one of globin chains produced in a small amount or not at all formed.Normally, the formation of the protein globin chains balanced.Number of α- and β-chains of the same, and free globin chains not normally happen.Impaired synthesis of one of them leads to imbalance.The chain, which is produced in excessive amounts, is compacted and deposited in erythrokaryocytes (cells of the bone marrow, which are the precursors of red blood cells).Linked to this is a large part of the manifestations of thalassemia.The absence of α-chain in the fetus leads to the development of hydrocephalus and fetal death.

in the development of manifestations of thalassemia major importance is attached to the excess amount of a globin chain.Thus, when β-thalassemia due to a violation of the synthesis of β-chain is a lot of free alpha-chains.If the redundant circuit is not part of the fetal hemoglobin, they condense and precipitate.Excessive formation of α-chain is a major cause of inefficient formation of mature red blood cells with β-thalassemia.Erythrokaryocytes (red blood cell progenitors) in bone marrow are killed.The death of the bone marrow erythrokaryocytes leads to pronounced anemia.In the spleen and liver lesions may appear red additional hematopoiesis.Excessive blood formation in the bone leads to their deformation, expressed lack of oxygen (hypoxia) - a violation of the child's development.Between the deep and anemia with excess α-chain with β-thalassemia there is a clear connection.When α-thalassemia in the absence of formation of α-chain and in connection with this hemoglobin A (adult hemoglobin) and F (fetal hemoglobin) developing fetal hydrops, which leads to its death.The excess β-chains can form in thalassemia hemoglobin consisting of 4β-chains - hemoglobin N. cells containing hemoglobin H, easily removed from the blood spleen, where they are destroyed.Anemia during the formation of hemoglobin H erythrocyte destruction due to both the spleen and violation globin protein formation.