Jul 29, 2015 alpha thalassemia is a blood disorder that reduces the bodys production of hemoglobin. Cyprus is the third largest island in the mediterranean, having 633,000 inhabitants. There are two copies of the hemoglobin alpha gene hba1 and hba2, which each encode an. Thalassemia in arab populations alpha and beta thalassemia are endemic in almost all arab countries probably due to the historical presence of malaria in the region and the high level of consanguinity. The alpha chain is involved in alpha thalassemia and the beta chain is affected in the more familiar beta thalassemia. Combination of a triple alphaglobin gene with betathalassemia in a gypsy family.
Laboratory diagnosis of hemoglobinopathies and thalassemia. Instructions and contact information for referring a thalassemia patient to our center are also included. Hemoglobin consists of four protein subunits, typically two subunits of betaglobin and two subunits of another protein called alphaglobin. In alpha thalassemia, the severity of thalassemia you have depends on the number of gene mutations you inherit from your parents.
Both of these genes provide instructions for making a protein called alphaglobin, which is a component subunit of hemoglobin people have two copies of the hba1 gene and two copies of the hba2 gene in each cell. If mutations allows production of a small amount of functional. Beta0 thalassemia refers to the absence of production of beta globin. Alpha thalassemia major is almost uniformly fatal in utero without intervention.
Sep 29, 2017 thalassemia is a genetic disease that results in abnormal globin synthesis, therefore abnormal hemoglobin formation, and microcytic anemia. Learn how to differentiate alpha and beta thalassemia. Introduction to alpha thalassaemia city hospital, birmingham. The hemoglobin protein affected in alpha thalassemia is the alpha globin. Alpha thalassemia alpha thalassemia is due to impaired or absent production of alpha globin chains, which leads to a relative excess of gamma globin chains in the fetus and newborn, and excess beta globin chains in children and adults. People who inherit hemoglobin genes that are altered or missing from one parent but inherit normal genes from the other parent are called carriers. Aug 23, 2018 thalassemia is a blood disorder that is caused by dna mutations in cells that are responsible for producing haemoglobin. This causes a shortage of red blood cells and low levels of oxygen in the bloodstream, leading to a variety of health problems. Alpha thalassemia usually caused by gene deletion beta thalassemia usually caused by mutation. Depending on the severity of symptoms three categories may be identified.
Started in 1995, this collection now contains 6760 interlinked topic pages divided into a tree of 31 specialty books and 732 chapters. What does it mean to be a carrier of alpha plus thalassemia. Carrying the gene for alpha plus thalassaemia does not cause any illness, however it. Alpha thalassemia major is a very serious disease of severe anemia characterized by. However, they can pass the faulty genes on to their children. The purpose of this study was to appraise the problem of thalassaemia in cyprus, where preliminary evidence had indicated that both forms of thalassemia, alpha and beta, were common. Beta thalassemia major causes hemolytic anemia, poor. A total of 6946 subjects were enrolled for evaluating alphabeta thalassemia from 2012 to 2018. This is the main difference between alpha and beta thalassemia. Alpha thalassemia is caused by reduced or absent production of alpha globin subunits, while beta thalassemia is caused by reduced or absent production of beta globin subunits. Alpha thalassemia is particularly common among people of african, mediterranean, or southeast asian ancestry. Those that result in the functional depletion of both pair of. Alpha thalassemia is caused by reduced or absent production of alphaglobin subunits, while beta thalassemia is caused by reduced or absent production of betaglobin subunits.
Alphathalassemia types, causes, diagnosis, treatment. Like the silent carrier, alpha thalassemia trait is not a disease and does not affect your health. Jan 01, 2015 beta thalassemia is caused by changes mutations in the hbb gene while alpha thalassemia is caused by mutations in the hba1 and or hba2 genes. Jan 11, 2018 the alpha chain is involved in alpha thalassemia and the beta chain is affected in the more familiar beta thalassemia. The most severe form of alpha thalassemia major causes stillbirth death of the unborn baby during birth or the late stages of pregnancy children born with beta thalassemia major cooley anemia are normal at birth, but develop severe anemia during the first year of life other symptoms can include. In alpha thalassemia, the amount of alpha chains is decreased, and in betathalassemia, the number of beta chains is decreased. Both are inherited in an autosomal recessive manner. The inheritance of alphathalassemia, however, is more complex because of the involvement of one or more genes.
Beta thalassemia is more common among people of mediterranean, middle eastern, southeast asian, or indian ancestry. The degree of excess nonfunctional alpha chains is the major predictor of disease severity. Alpha thalassemia normal production of alpha chains is absent which results in excess production of gamma globin chains in the fetus and newborn or beta globin chains in children and adults. It is passed down from one or both parents through their genes. Alpha thalassemia major with hemoglobin barts usually results in fatal hydrops fetalis. Thalassemias are a group of inherited microcytic, hemolytic anemias characterized by defective hemoglobin synthesis. Beta thalassemia trait when you have one working copy of the beta globin gene and one nonworking copy you have beta thalassemia trait. Betathalassemia associated with other hb anomalies. Adult hemoglobin composed two alpha and two beta chains. Potential fetal therapies are available, including transfusing the developing fetus with red blood cells to.
Betathalassemia is a blood disorder that reduces the bodys production of hemoglobin. Thalassemia is an inherited blood disorder that is passed down through the parents genes. Alpha thalassemia minor and beta thalassemia minor, also known as alpha thalassemia trait or beta thalassemia trait, are common conditions in many demographics. Grasp the cellular pathogenesis of alpha and beta thalassemias. This leads to a reduction in the number and ability of the red blood cells. Heterozygotes with defects in two of the four genes result in alpha thalassemia trait, and tend to develop mild to moderate microcytic anemia but with no symptoms. It is normal for people whose ancestors come from these areas to carry mild alpha thalassaemia, so you should not worry about it. Dec 12, 2011 mutated thalassemia alpha 0 thalassemia more than 20 mutations have been found. Betathalassemia prevalence, pathophysiology and inheritance. Thalassemia is a common cause of anemia, especially microcytic anemia. Download as ppt, pdf, txt or read online from scribd. Alpha thalassemia intermedia, or hbh disease, causes microcytic anemia.
Alphathalassemia is one of the most common hemoglobin genetic abnormalities and is caused by the reduced or absent production of the alpha globin chains. On the other hand, deletion of three genes results in significant production of hemoglobin h consisting of four beta chain. While the excess beta globin chains are capable of forming soluble homotetramers beta4, hbh, they are. Individuals with thalassemia major have severe anemia and hepatosplenomegaly. Alpha thalassemia multiplex ligation dependent probe amplification mlpa and multiplex pcr alpha globin sequencing beta thalassemia beta globin sequencing the test examines the complete beta globin coding sequence, the splice sites and other intronic regions known to harbor mutations, the proximal promoter region. When the words trait, minor, intermedia, or major are used, these words describe how severe the thalassemia is. Thalassemias are a group of inherited blood conditions which result in the impaired production of hemoglobin, the molecule that carries oxygen in the blood. The word thalassemia comes originally from the greek. Silent carrier state the mildest form of beta thalassemia.
Combination of a triple alphaglobin gene with beta. This student paper was written as an assignment in. In alpha thalassemia, the amount of alpha chains is decreased, and in beta thalassemia, the number of beta chains is decreased. Alpha thalassemia alpha thalassemia is the result of changes in the genes for the alpha globin component of hemoglobin.
Difference between alpha and beta thalassemia compare the. Beta thalassemia is one type of thalassemia, a blood disorder caused by dna mutations in cells that create hemoglobin. Alpha thalassemia in alphathalassemia, the alpha genes are deleted. Carriers of alpha thalassemia usually have no signs or symptoms. Betathalassemia is caused by reduced or absent synthesis of the betaglobin chains of the adult hemoglobin tetramer hba, which is made up of two. A person who has thalassemia trait may not have any symptoms at all or may have only mild anemia, while a person with thalassemia. Alpha thalassemia trait causes the size of the red blood cells to be smaller than usual. In beta thalassemia, the gene for making beta globin chains doesnt work normally. Depending on family history, if a persons parents or grandparents had beta thalassemia major or intermedia, there is a 75% 3 out of 4 probability see inheritance chart at top of page of. Ppt thalassemia powerpoint presentation free to download. Alphathalassemia types, causes, diagnosis, treatment and. Our thalassemia research and care update and clinical practice guidelines for physicians is available for download on this page.
There are two main forms of betathalassemia, classified based on. Carrier frequencies of beta thalassemia vary from 1% to 5% while prevalence data for alpha thalassemia are scant. Difference between alpha and beta thalassemia compare. Family history and ancestry are factors which increase the risk of beta thalassemia. There are different types of thalassaemia, which can be divided into alpha and beta thalassaemias. They are forms of thalassemia caused by reduced or absent synthesis of the beta chains of hemoglobin that result in variable outcomes ranging from severe anemia to clinically asymptomatic individuals. Alpha thalassemia is a result of decreased production of alpha globins. Results in microcytic, hypochromic anemias of varying severity. Normal hemoglobin consists of two alpha chains and two beta chains. Thalassemia is due to a deficit or absent production of. Thalassemia is an inherited blood disorder that reduces the production of functional hemoglobin the protein in red blood cells that carries oxygen. Betathalassemia is more common among people of mediterranean, middle eastern, southeast asian, or indian ancestry.
Beta thalassemia trait and beta thalassemia disease. Etiology mutation in the dna of cells that produce hemoglobin inheritance 5. Impaired 1, 2, 3, or 4 alpha globin chain productions can lead to a comparative excess of the beta globin chains. Alpha thalassemia nord national organization for rare. The hbb gene provides instructions for making a protein called betaglobin. Describe the clinical and laboratory features of beta thalassemia minor trait and beta thalassemia major and the different types of alpha thalassemia. Low levels of hemoglobin lead to a shortage of mature red blood cells and a lack of oxygen in the body. Its also possible to be a carrier of thalassaemia, also known as having the thalassaemia trait.
Alpha thalassemia intermedia, or hemoglobin h disease, causes. Two types of alpha thalassemia can cause health problems. Alpha thalassemia trait a person with two working copies of the alpha globin gene has alpha thalassemia trait. Pdf on mar 21, 2012, vefik arica and others published alpha thalassemia disorders find, read and cite all the research. Dharmesh chandra sharma 1, anita arya 2, purni ma kishor 3. Alpha thalassemia major atm occurs when all four genes are nonfunctioning. A positive family history of alpha or betathalassemia is an impor.
A rare example that coinheritance of a severe form of betathalassemia and alphathalassemia interact in a synergistic manner to balance the phenotype of classic thalassemic syndromes. Thalassemia is a type of thalassemia that is caused by a deficiency of the alpha globin protein. Heterozygotes with defects in two of the four genes result in alpha thalassemia trait, and tend to develop mild to. People with betathalassemia have anemia, which can cause paleness, weakness, fatigue, and more serious complications. The interaction of hbe and betathalassemia results in thalassemia phenotypes ranging from a condition indistinguishable from thalassemia major to a mild form of thalassemia intermedia. Thalassemia genetic and rare diseases information center. Affected people have anemia, which can cause pale skin, weakness, fatigue, and more serious complications. Alpha thalassemia, the heterozygous state with a single gene for alpha thalassemia, causes no symptoms or merely mild anemia because there is another gene still able to make alpha chains. Nov 22, 2019 in thalassemia, the production of either the alpha or beta chains are reduced, resulting in either alpha thalassemia or beta thalassemia. Homozygotes betathalassemia major or cooleys anemia develop severe anemia and bone marrow hyperactivity. Alpha thalassemia is one of the most common hemoglobin genetic abnormalities and is caused by the reduced or absent production of the alpha globin chains. Characterized by two defective genes but almost no. Alphathalassemia is particularly common among people of african, mediterranean, or southeast asian ancestry.
Thalassemia can be categorized broadly into two main categories as alpha thalassemia and beta thalassemia. Alphathalassemia genetic and rare diseases information. Other types include beta thalassaemia intermedia, alpha thalassaemia major and haemoglobin h disease. A total of 6946 subjects were enrolled for evaluating alpha beta thalassemia from 2012 to 2018.
Beta thalassemia disorders result from decreased production of beta globin chains, resulting in relative excess of alpha globin chains. Alpha and beta thalassemia american family physician. Understand the pathophysiologic principles underlying treatment of beta thalassemia major. The more mutated genes, the more severe your thalassemia. Translations of brochures about thalassemia, thalassemia trait, and hemoglobin h disease are available here in pdf format for the following languages. The propositus of the first family had mild cooleys anemia and was believed to have one. Alpha thalassemia typically results from deletions involving the hba1 and hba2 genes. Heterozygotes for a single gene defect results in silent alpha thalassemia state. Kanavakis e, traegersynodinos j, lafioniatis s, et al.
435 1283 288 260 954 933 132 122 826 833 1473 468 219 608 454 446 528 858 1211 871 419 703 253 1422 1385 366 1482 375 426 35 930 342 1113 107 516