Symptoms of thalassemia major Thalassemia is an inherited genetic disease caused by defects in the formation of hemoglobin protein chains. Thalassemia is divided into two types: alpha thalassemia and beta thalassemia. Beta thalassemia itself includes thalassemia major (severe thalassemia) and thalassemia minor or mild thalassemia. A person with thalassemia minor has inherited a healthy gene …