Alpha-thalassemia

There are 4 genes that control the formation of α-chains of globin in the human body. In the complete absence of the α-chain, fetal hemoglobin is not synthesized in the fetus, hydrocephalus develops, and then death occurs. If the function of 1 or 2 genes is disturbed, anemia develops, in most cases not severe. The manifestations of α-thalassemia with a lesion of 2 genes depend on which genes are affected, and almost completely repeat heterozygous β-thalassemia. Often increases the size of the spleen, less often - the liver. A moderate anemia, a slight increase in the level of reticulocytes( immature forms of erythrocytes), a slight increase in bilirubin in the blood and an increase in serum iron are determined. Usually blood relatives have the same anemia.

However, in contrast to β-thalassemia, the amount of fetal hemoglobin and hemoglobin A does not increase with α-thalassemia.

α-thalassemia can be detected only when studying the formation of globin chains in a test tube, which is performed in specialized laboratories, α-thalassemia can sometimes be detectedin newborns in the study of blood by electrophoresis.

Hemoglobinopathy H is one of the variants of α-thalassemia. It is relatively uneventful, manifested by a significant increase in the spleen and liver, a slight jaundice due to an increase in the amount of bilirubin, anemia of varying severity, but more often the hemoglobin content is not lower than 70-80 g / l. Hemoglobinopathy H differs from other forms of thalassemia by multiple small inclusions in all erythrocytes, which are visible under a microscope when staining red blood cells.

A-β-thalassemia

A-β-thalassemia is accompanied by a disruption in the synthesis of both the α- and β-chains of the globin protein. In its manifestations, heterozygous αβ-thalassemia does not differ from heterozygous β-thalassemia. Usually, the amount of hemoglobin A is increased in heterozygous β-thalassemia. However, hemoglobin A contains an α-chain and, therefore, in the combination of β- and α-thalassemia, there is no most characteristic laboratory sign of β-thalassemia - an increase in the hemoglobin A content. Often there is an increase in hemoglobinF with a normal or reduced amount of hemoglobin A( the so-called HbF-thalassemia).In homozygous β-thalassemia, combined with α-thalassemia, the child has only hemoglobin F, while hemoglobin A is either very small or nonexistent.