![]() Thus, such transfused patients quickly become iron overloaded. Iron, in addition to being relatively difficult to absorb, is also not easily excreted. With each milliliter of transfused packed red blood cells, the patient receives one milligram of elemental iron. This will, in effect, shut off the patient's own erythropoiesis and stop the vicious cycle of anemia stimulating "ineffective erythropoiesis". The intent of these transfusions is to keep their hemoglobin trough above 9 or 10 gm/dl. In untreated patients, death usually occurs by the end of the second decade of life from anemia and congestive heart failure.Ĭurrently, part of the standard treatment for beta thalassemia major is lifelong transfusions given every 2-4 weeks. Erythrocytes that do enter the circulation are noted to be abnormal by the reticuloendothelial system (spleen and liver), and are taken up by these organs with ensuing enormous hepatosplenomegaly. With time, the marrow cavities (skull bones, facial bones, and ribs) expand, leading to the classical facial features and skull X-ray findings ("hair on end" in untreated patients due to excessive extramedullary hematopoiesis). This process is called "ineffective erythropoiesis". Peripheral anemia, caused by the disease, sends signals to the bone marrow to increase production of erythrocytes (e.g., via erythropoietin), however, erythrocyte production is abnormal (ineffective). ![]() Beta thalassemia presents at 6 months of age when adult hemoglobin has replaces fetal hemoglobin. Since beta chains are not present in fetal hemoglobin, beta thalassemia does not manifest itself in newborns. This typically requires no treatment other than recognition for the purposes of patient education, to avoid supplemental iron, and for genetic counseling.īeta thalassemia major, historically called Cooley's Anemia, occurs when both genes necessary for beta globin production are affected. This abnormal hemoglobin is very unstable, and leads to erythrocyte death in the bone marrow.īeta thalassemia minor occurs when only one gene is affected, causing a moderate, lifelong anemia. In beta thalassemia, there is a large lack of normal beta chain production, thus causing a relative excess amount of alpha chains, which clump together. The alpha and beta genes are located on different chromosomes and therefore, abnormalities of each are inherited separately.īeta thalassemia usually occurs from abnormal beta genes, or less commonly, a deletion of a beta gene. Occasionally, the entire gene (on one allele) is actually deleted. Beta thalassemia usually results from an abnormal gene in one or both of the genes necessary for beta globin chain production. Occasionally, an alpha globin gene is abnormal instead of being completely deleted. Alpha thalassemia usually results from the deletion of any number of the 4 genes necessary to make alpha globin chains. They have nothing to do with one another. There are two basic types of thalassemia: alpha thalassemia and beta thalassemia. In fact, in thalassemia over time, the body becomes iron overloaded, and iron is "stored" in the organs (liver, endocrine organs and heart), which can cause significant morbidity and mortality. Since thalassemia is not an iron deficiency problem, it is not be corrected by additional iron. Even in non-transfused patients, iron overload is often noted in the more severe forms of thalassemia. In any anemic state, there is increased gut absorption of iron. Whereas both thalassemia and iron deficiency anemia are characterized by microcytic hypochromic anemias, iron deficiency anemia is easily corrected with iron supplementation, but iron supplementation does not correct the anemia due to thalassemia. Thalassemia is one of the most confusing of the hemoglobinopathies, mostly due to confusing nomenclature, lack of easy diagnostic tests, and its similarity to iron deficiency anemia. On a review of this child's medical record, you note the presence of Hemoglobin Barts on her newborn screen. She is otherwise healthy and has no complaints. Burns School of MedicineĪ 12 month old female of Hawaiian, Chinese, Portuguese and Japanese ethnicity is noted to have a hemoglobin of 9.1 g/dl with an MCV of 58 on a routine CBC screen at her one year well child check up. Case Based Pediatrics Chapter Case Based Pediatrics For Medical Students and Residentsĭepartment of Pediatrics, University of Hawaii John A.
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