1, type of hemoglobin
HbA2 is a kind of human hemoglobin, because there are three types of hemoglobin in normal adults:
The first is HbA, that is, hemoglobin A, which is also the most common hemoglobin, accounting for more than 95% of all hemoglobin.
The second is hemoglobin A2, which accounts for about 2%-3% of all hemoglobin in peripheral blood.
The third is hemoglobin F, also called fetal hemoglobin. The content in the fetus is high, and the concentration drops rapidly after birth. If the concentration of adult hemoglobin A2 increases, adult hemoglobin F will not exceed 65438 0%.
This situation is common in some patients with β thalassemia, and it can also be seen in patients with β thalassemia if hemoglobin F is elevated. The determination of hemoglobin A2 has certain guiding significance for the diagnosis of thalassemia.
2. Symptoms of high/low hba2
The normal reference range of HbA2 is generally 2.5%-3.5%. In general, high HbA2 may indicate the presence of β -thalassemia. Thalassemia is a hemolytic disease related to globin synthesis disorder, which is mainly divided into α type and β type.
If HbA2 is low, there is anemia, among which iron deficiency anemia and sideroblastic anemia are the most common.
Hba and hba2 are different kinds of hemoglobin.
High HbA2 is indeed a typical manifestation of β thalassemia. Considering that HbA still accounts for the vast majority, it should be mild. The suggestion of genetic testing for thalassemia is completely correct. Because thalassemia is a genetic disease, the diagnosis of thalassemia is of great significance to the health of the next generation.
Thalassemia is a hereditary hemolytic anemia, also known as marine anemia. The composition of hemoglobin has changed the clinical symptoms of this group of diseases, most of which are chronic progressive hemolytic anemia and thalassemia. Severe patients usually can't survive.
Thalassemia (thalassemia for short) is the most common and harmful genetic disease in southern provinces (regions) of China, and the population incidence rate is as high as 10%. There are mainly two kinds of thalassemia, α and β, and α thalassemia is more common.