A hemoglobin electrophoresis is the most widely used test to confirm thalassemia. It separates the different types of hemoglobin so that they can be measured. A high percentage of fetal hemoglobin (HbF) indicates thal major.
However, thalassemia intermedia is defined by non-dependence on transfusions, even though normally, an intermedia will have two beta thal genes, just like a major. In intermedia, even though both genes may be affected, there is still enough hemoglobin production for the patient to survive without transfusions. Majors cannot survive unless transfusions are started within the first few years of life. Many intermedias do require transfusions later in life as their hemoglobin levels are not enough to maintain a reasonable quality of life, but because they did not transfuse before adulthood, they are considered to be intermedias. Generally, if your body can maintain a hemoglobin level somewhere in the 6-7 range without regular transfusions, you will be classified as intermedia.
From
http://www.emedicine.com/ped/topic2232.htmThalassemia intermedia is a term used to define a group of patients with beta thalassemia in whom the clinical severity of the disease is somewhere between the mild symptoms of beta thalassemia trait and the severe manifestations of beta thalassemia major. The diagnosis is a clinical one based on the patient maintaining a satisfactory hemoglobin (Hb) level of at least 6-7 g/dL at the time of diagnosis without the need for regular blood transfusions...Because of the significant overlap in clinical severity among the three types of beta thalassemia and despite the fact that several genotypes are associated with the beta thalassemia intermedia picture, the diagnosis continues to be a clinical one regardless of the genotype involved. Moreover, in an individual patient, the diagnosis may change from thalassemia intermedia to thalassemia major once the patient begins to have more severe symptoms and to require regular blood transfusions...The symptoms of thalassemia intermedia reflect ineffective erythropoiesis, which leads to anemia, medullary expansion, and extramedullary hematopoiesis. Iron overload is a potential complication of thalassemia, even in patients not requiring red blood cell transfusions. It results from excessive absorption of dietary iron, a consequence of ineffective erythropoiesis and rapid turnover of plasma iron.
Iron overload can prove to be a serious problem in intermedia and serum ferritin levels should be checked periodically.
Any of these tests are simple blood tests and pose no danger.