Thalassemia is caused by mutations in the DNA of cells that make hemoglobin — the substance in red blood cells that carries oxygen throughout your body. The mutations associated with thalassemia are passed from parents to children. There are 2 kind of thalassemia, alpha-thalassemia and beta-thalassemia.
In alpha-thalassemia, the severity of thalassemia you have depends on the number of gene mutations you inherit from your parents. The more mutated genes, the more severe your thalassemia. In beta-thalassemia, the severity of thalassemia you have depends on which part of the hemoglobin molecule is affected.
