What typically causes Beta-Thalassemia?

Beta-thalassemia is primarily caused by gene mutations that affect the synthesis of the beta globin chain of hemoglobin. The mutations can occur in the HBB gene located on chromosome 11, which is responsible for producing the beta globin component of hemoglobin. These mutations can lead to reduced or absent production of beta globin, resulting in an imbalance between alpha and beta chains and ultimately causing the clinical features associated with beta-thalassemia, such as anemia and the compensatory expansion of erythropoiesis in the bone marrow.

The mutations may include point mutations, which are single nucleotide changes, and sometimes small insertions or deletions that disrupt normal gene function. Due to this gene-level alteration, the major pathology seen in beta-thalassemia arises from the resultant ineffective erythropoiesis and hemolysis of red blood cells. This makes gene mutations the primary etiology of beta-thalassemia rather than deletions, nutritional deficiencies, or chromosomal abnormalities, which are more characteristic of other hematologic conditions.