thalassemia causes symptoms and treatment pdf

Thalassemia causes symptoms and treatment pdf

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What is beta thalassemia?

Thalassemias

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Thalassemias are a group of inherited microcytic, hemolytic anemias characterized by defective hemoglobin synthesis.

Alpha-thalassemia is particularly common among people of African, Mediterranean, or Southeast Asian ancestry. Symptoms and signs result from anemia, hemolysis, splenomegaly, bone marrow hyperplasia, and, if there have been multiple transfusions, iron overload. Diagnosis is based on genetic tests and quantitative hemoglobin analysis.

Treatment for severe forms may include transfusion, splenectomy, chelation, and stem cell transplantation. See also Overview of Hemolytic Anemia. Thalassemia is a hemoglobinopathy that is among the most common inherited disorders of hemoglobin production. The normal adult hemoglobin molecule Hb A consists of 2 pairs of chains designated alpha and beta. Thalassemia results from unbalanced hemoglobin synthesis caused by decreased production of at least one globin polypeptide chain beta, alpha, gamma, delta.

Alpha-thalassemia results from decreased production of alpha-polypeptide chains due to a deletion of one or more alpha genes. People normally have four alpha genes two on each of a pair of chromosomes because the alpha gene is duplicated. Disease classification is based on the number and location of deletions:.

Beta-thalassemia results from decreased production of beta-polypeptide chains due to either mutations or deletions in the beta globin gene, leading to impaired production of hemoglobin Hb A.

There are two beta globin genes, and patients may have heterozygous, homozygous, or compound heterozygous mutations. In addition, patients may be heterozygous or homozygous for abnormalities in 2 different globin genes eg, beta and delta.

Beta-delta-thalassemia is a less common form of beta-thalassemia in which production of both the delta chain as well as the beta chain is impaired. These mutations may be heterozygous or homozygous. Clinical features of thalassemias are similar but vary in severity depending on the amount of normal hemoglobin present.

These patients have alpha-thalassemia trait. Patients with Hb H disease often have symptomatic hemolytic anemia and splenomegaly. In beta-thalassemia, clinical phenotypes are classified into 3 groups based on the degree to which beta globin production is impaired:. These patients develop severe anemia and bone marrow hyperactivity.

Beta-thalassemia major manifests by age 1 to 2 years with symptoms of severe anemia and transfusional and absorptive iron overload. Patients are jaundiced, and leg ulcers and cholelithiasis occur as in sickle cell disease.

Splenomegaly, often massive, is common. Splenic sequestration may develop, accelerating destruction of transfused normal red blood cells. Bone marrow hyperactivity causes thickening of the cranial bones and malar eminences. Long bone involvement predisposes to pathologic fractures and impairs growth, possibly delaying or preventing puberty.

With iron overload , iron deposits in heart muscle may cause heart failure. Hepatic siderosis is typical, leading to functional impairment and cirrhosis. Iron chelation is usually necessary. Thalassemia trait is commonly detected when routine peripheral blood smear and complete blood count show microcytic anemia and elevated red cell count.

If desired, the diagnosis of beta thalassemia trait can be confirmed with quantitative hemoglobin studies. No intervention is needed; in women, anemia can be worsened by pregnancy. More severe thalassemias are suspected in patients with a family history, suggestive symptoms or signs, or microcytic hemolytic anemia. If thalassemias are suspected, laboratory tests for microcytic and hemolytic anemias and quantitative hemoglobin studies are done.

Serum bilirubin, iron, and ferritin levels are increased. In alpha-thalassemias, the percentages of Hb F and Hb A2 are generally normal, and the diagnosis of single or double gene defect thalassemias may be carried out with newer genetic tests. The diagnosis often is one of exclusion of other causes of microcytic anemia.

Red blood cell count is elevated relative to hemoglobin because the cells are very microcytic. The blood smear is virtually diagnostic, with many nucleated erythroblasts; target cells; small, pale red blood cells; and punctate and diffuse basophilia. In quantitative hemoglobin studies, elevation of Hb A2 is diagnostic for beta-thalassemia minor. The specific molecular defect can be characterized but does not alter the clinical approach. Recombinant DNA approaches of gene mapping particularly polymerase chain reaction [PCR] have become standard for prenatal diagnosis and genetic counseling.

If bone marrow examination is done for anemia eg, to exclude other causes , it shows marked erythroid hyperplasia. Imaging tests done for other reasons in patients with beta-thalassemia major show changes due to chronic bone marrow hyperactivity. The skull may show cortical thinning, widened diploic space, a sun-ray appearance of the trabeculae, and a granular or ground-glass appearance.

The long bones may show cortical thinning, marrow space widening, and areas of osteoporosis. The vertebral bodies may have a granular or ground-glass appearance.

The phalanges may appear rectangular or biconvex. Chest imaging may reveal evidence of paravertebral extramedullary hematopoiesis. Life expectancy is normal for people with beta-thalassemia minor or alpha-thalassemia minor.

The prognosis of Hb H disease and beta-thalassemia intermedia varies. Life expectancy is decreased in people with beta-thalassemia major mostly due to complications from chronic transfusions. Luspatercept for treatment of transfusion-dependent beta thalassemia. Patients with beta-thalassemia intermedia should receive as few transfusions as possible to avoid iron overload.

However, suppression of abnormal hematopoiesis by periodic red blood cell transfusion may be valuable in severely affected patients. To prevent or delay complications due to iron overload, excess transfusional iron must be removed eg, via chronic iron chelation therapy.

Splenectomy may help decrease transfusion requirements for patients with significant splenomegaly. Luspatercept is an injectable recombinant fusion protein that inhibits signalling of the transforming growth factor beta pathway.

Luspatercept is an option for treatment in transfusion-dependent patients 1. Allogeneic stem cell transplantation is the only curative option and should be considered in all patients. N Engl J Med 13 —, Thalassemias result from decreased production of at least one globin polypeptide chain beta, alpha, gamma, delta ; the resultant abnormal red blood cells are microcytic, often abnormally shaped, and prone to hemolysis causing anemia.

Splenomegaly, often massive, is common and can result in splenic sequestration that accelerates destruction of red blood cells including transfused ones. Iron overload is common because of increased absorption due to defective erythropoiesis and frequent transfusions.

The following is an English-language resource that may be useful. Cooley's Anemia Foundation : provides comprehensive patient education and support and advocacy to patients with thalassemia.

From developing new therapies that treat and prevent disease to helping people in need, we are committed to improving health and well-being around the world. The Manual was first published as the Merck Manual in as a service to the community. Learn more about our commitment to Global Medical Knowledge. This site complies with the HONcode standard for trustworthy health information: verify here.

Common Health Topics. Videos Figures Images Quizzes. Alpha-thalassemia Beta-thalassemia. Symptoms and Signs. Treatment reference. Key Points. More Information. Anemias Caused by Hemolysis. Test your knowledge. Which of the following immunotherapy approaches has demonstrated great potential in early clinical trials in patients with B-cell leukemia?

More Content. Click here for Patient Education. Minor or trait. Evaluation for hemolytic anemia if suspected. Often red blood cell transfusion, with or without iron chelation therapy.

In patients with alpha-thalassemia trait or beta-thalassemia trait, no treatment is needed. In Hb H disease, splenectomy may be helpful if anemia is severe or splenomegaly is present. Transfuse as needed, but monitor for iron overload and use chelation therapy. Splenectomy may help decrease transfusion requirements for patients with splenomegaly. Was This Page Helpful? Yes No. Overview of Vascular Bleeding Disorders. Hemoglobin S—Beta-Thalassemia Disease. Hemoglobin E Disease.

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Only comments seeking to improve the quality and accuracy of information on the Orphanet website are accepted. For all other comments, please send your remarks via contact us. Only comments written in English can be processed. Beta-thalassemia BT intermedia is a form of BT see this term characterized by mild to moderate anemia which does not or only occasionally requires transfusion. Annual incidence of BT intermedia is not known. BT intermedia encompasses a wide clinical spectrum with more severe cases presenting between 2 and 6 years of age with anemia, spleen and sometimes liver enlargement, as well as delayed growth and development. In other cases, patients are completely asymptomatic until adult life with only mild anemia.

Thalassemias are a group of inherited microcytic, hemolytic anemias characterized by defective hemoglobin synthesis. Alpha-thalassemia is particularly common among people of African, Mediterranean, or Southeast Asian ancestry. Symptoms and signs result from anemia, hemolysis, splenomegaly, bone marrow hyperplasia, and, if there have been multiple transfusions, iron overload. Diagnosis is based on genetic tests and quantitative hemoglobin analysis. Treatment for severe forms may include transfusion, splenectomy, chelation, and stem cell transplantation.

What is beta thalassemia?

Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in , throughout the world and 1 in 10, people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell RBC transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow.

Thalassemia is an inherited blood disorder in which the body makes an abnormal form of hemoglobin. Hemoglobin is the protein molecule in red blood cells that carries oxygen. The disorder results in excessive destruction of red blood cells, which leads to anemia. Thalassemia is inherited, meaning that at least one of your parents must be a carrier of the disorder.

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Thalassemias

Thalassemia is a blood disorder passed down through families inherited in which the body makes an abnormal form or inadequate amount of hemoglobin. Hemoglobin is the protein in red blood cells that carries oxygen. The disorder results in large numbers of red blood cells being destroyed, which leads to anemia. Thalassemia occurs when there is a defect in a gene that helps control production of one of these proteins. Alpha thalassemias occur most often in people from Southeast Asia, the Middle East, China, and in those of African descent. Beta thalassemias occur most often in people of Mediterranean origin. To a lesser extent, Chinese, other Asians, and African Americans can be affected.

An overview of the causes, symptoms and treatment of this blood disorder caused by a defect in the gene that controls the production of hemoglobin. Thalassemia is a group of blood diseases caused by production of abnormal hemoglobin. Hemoglobin is a protein found in red blood cells that carries oxygen to the body.

Most children with moderate to severe thalassemia show signs and symptoms within their first two years of life.

Beta Thalassemia

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Thalassemias are a group of blood disorders that affect the way the body makes hemoglobin. Hemoglobin is a protein found in red blood cells that carries oxygen throughout the body. It's made up of alpha globin and beta globin. The body contains more red blood cells than any other type of cell, and each has a life span of about 4 months. Each day, the body produces new red blood cells to replace those that die or are lost from the body. With thalassemia, the red blood cells are destroyed at a faster rate, leading to anemia , a condition that can cause fatigue and other complications. Thalassemias are inherited conditions — they're carried in the genes and passed on from parents to children.

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Thalassemia

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1 comments

  • Arthur C. 20.11.2020 at 03:18

    A person with thalassemia will have too few red blood cells and too little hemoglobin, and the red blood cells may be too small.

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