Symptoms appear in the first two years of life and include paleness of the skin, poor appetite, irritability, and failure to grow. Thalassemia omim 141800 is the most common inherited disorder of hemoglobin hb synthesis in the world, with gene frequencies varying between 1% and 98% throughout the tropics and subtropics. Jun 17, 2011 inheritance of hemoglobin genes from parents with thalassemia trait. Thalassemias slide 1 by the end of the lecture, the. In beta thalassemia, the gene for making beta globin chains doesnt work normally. Alpha thalassemia disease and beta thalassemia disease. Apr 03, 2018 thalassaemia major genetics of thalassemia adult hemoglobin composed two alpha and two beta chains. The association of the g6pd defect with this thalassemia gene complex may eventually contribute to this effect. Along with patient care, medical research is a primary focus at the comprehensive thalassemia center at ucsf benioff childrens hospital oakland. Beta thalassemia can combine with other altered beta genes and cause problems also. 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.
The thalassemias are an inherited group of disorders in which mutations in genes expressing alpha globin or beta globin result in impaired hemoglobin synthesis and microcytic anemia of varying severity. Full text full text is available as a scanned copy of the original print version. Beta thalassemia trait when you have one working copy of the beta globin gene and one nonworking copy you have beta thalassemia trait. Depending on family history, if a persons parents or grandparents had beta thalassemia major or intermedia, there is a 75%. Since reticulocytes manufacture equimolecular quantities of alpha and beta chains. What does it mean to be a carrier of alpha plus thalassemia. Normal alpha globin genes found on chromosome 16 people who do not produce enough alpha globin protein chains have alpha thalassemia. Grasp the cellular pathogenesis of alpha and beta thalassemias. A total of 6946 subjects were enrolled for evaluating alpha beta thalassemia from 2012 to 2018. The fact that you are a beta thalassaemia carrier means other members of your family could be carriers too. For example, a person with beta thalassaemia minor has one changed copy of the hbb gene, and one unchanged copy of the gene. There are two main types of thalassemia, alpha thalassemia and beta thalassemia. Your body makes less of the beta chains, but is still able to make plenty of. Thalassemia research and care at ucsf benioff childrens hospital oakland.
Carrying alpha zero thalassaemia a carrier can use this booklet to help explain carrying alpha zero thalassaemia to their partner, blood relatives and others. Thalassemias national library of medicine pubmed health. Is it possible to have both alpha thalassemia and beta. Phenotypic effect of heterozygous alpha and beta 0. Mutated thalassemia alpha 0 thalassemia more than 20 mutations have been found. Jan 11, 2018 the alpha chain is involved in alpha thalassemia and the beta chain is affected in the more familiar beta thalassemia. Results in microcytic, hypochromic anemias of varying severity. Because the alpha and beta thalassemia gene mutations are common, it is possible for a baby to inherit one from mom and another from dad. Nathan division of hematology of the department of medicine of the childrens hospital medical center, boston, massachusetts 02115. Hemoglobin, which carries oxygen to all cells in the body, is made of two different parts, called alpha and beta. 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.
Evaluation of alpha hemoglobin stabilizing protein ahsp as. Carrying alpha zero thalassaemia thalassemia club of thailand. To download a pdf file with information on alpha thalassemia. In general, this results in an excess of alpha globins that form insoluble tetrameric inclusions in the red blood cell.
The severity of alpha and beta thalassemia depends on how many of the four genes for alpha globin or two genes for beta globin are missing. Anemia is caused by a lower than normal number of red blood cells or not enough hemoglobin in the red blood cells. It is passed down from one or both parents through their genes. Hemoglobinopathy investigations genetic testing for beta or alpha globin genes 5 thalassemia disease is subcategorized into tdt and ntdt 6 management for tdt patients requires lifelong transfusions. Get all of these illustration organized by subject in pdf form at s. The following are pdf formatted files in various languages. Thalassemias slide 1 by the end of the lecture, the student. Alpha thalassemia trait a person with two working copies of the alpha globin gene has alpha thalassemia trait.
The severity of alpha and beta thalassemia depends on how many of the four genes for alpha globin or two genes for beta globin are. The two main types are called alpha and beta thalassemia, depending on which part of globin chain is produced in reduced amounts victor et al. Beta thalassemia is an inherited disease characterized by mild to severe anemia, poor growth, enlargement of the spleen, and skeletal changes. 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. Affected people have anemia, which can cause pale skin, weakness, fatigue, and more serious complications. Alpha thalassemia an overview sciencedirect topics. Alpha thalassemia, beta thalassemia, and sickle cell disease, collectively called hemoglobinopathies, are blood disorders with variable presentation ranging from chronic but treatable disease to a neonatal. Alpha thalassemia deletions found in suspected cases of beta. The parents of a person with an autosomal recessive condition each carry one copy of the mutated gene and are referred to as carriers.
Those that result in the functional depletion of both pair of. Laboratory diagnosis of hemoglobinopathies and thalassemia. Disorders of beta globin, such as sickle cell disease and beta thalassemia major, are not clinically apparent until several months of age, when the switch from hemoglobin f to hemoglobin a synthesis reveals the defect. Alphathalassemia genetic and rare diseases information. Individuals with thalassemia major usually present within the first two years of life. Alphathalassemia is a blood disorder that reduces the bodys production of hemoglobin. In undiagnosed cases screened for beta thalassemia major, we found mediterranean. Like the silent carrier, alpha thalassemia trait is not a disease and does not affect your health. Alpha thalassemia normally, alpha globin chain is made by four genes two from each parent, two on each strand of chromosome 16.
To download a pdf file with information on alpha thalassemia, please click here. Thalassemia includes a number of different forms of anemia red blood cell deficiency. Silent carrier state the mildest form of beta thalassemia. Beta thalassemia disease cooleys anemia information for physicians and other health care professionals definition beta thalassemia is an inherited red blood cell disorder that results in the complete absence or decreased synthesis of the beta. Thalassemias are a group of inherited blood conditions which result in the impaired production of hemoglobin, the molecule that carries oxygen in the blood. Betathalassemia genetic and rare diseases information. Human hemoglobin is a tetrameric protein consisting of two alpha. Beta thalassemia mechanism of disease beta thalassemia is a rare, inherited blood disorder characterized by low levels of hemoglobin, which resides in red blood cells and carries oxygen throughout the body. Clinically, both alpha and betathalassemia may occur in the major. Alpha thalassemia a normal person carries a linked pair of.
Jun 18, 2018 beta thalassemia major and beta thalassemia intermedia are usually inherited in an autosomal recessive manner, which means both copies of the hbb gene in each cell have mutations. Beta thalassemia major is the most severe form of beta thalassemia in which the. Carrier frequencies of beta thalassemia vary from 1% to 5% while prevalence data for alpha thalassemia are scant. It is a good idea to talk to your blood relatives such as your parents, brothers, sisters, uncles. If you need to, you can download the acrobat reader here. How i treat thalassemia blood american society of hematology. Scribd is the worlds largest social reading and publishing site. Alpha and beta thalassemia american family physician.
Oct 09, 2006 since thalassemia is not a single disorder but a group of related disorders that affect the human body in similar ways, it is important to understand the differences between the various types of thalassemia. Key difference alpha vs beta thalassemia thalassemia is a heterogeneous group of disorders caused by inherited mutations that decrease the synthesis of either alpha or beta globin chains, leading. Alpha thalassemia is common in africa, asia, and the mediterranean. Dec 12, 2011 mutated thalassemia alpha 0 thalassemia more than 20 mutations have been found.
Because they have one functioning copy of the gene, their health is not affected by beta thalassaemia. Coinheritance of alpha thalassemia 1 and hemoglobin e beta zero thalassemia. Diagnosis of beta thalassemia can be done by fetal dna analysis for. Most beta thalassemia cases result from nucleotide deletions or substitutions. Beta thalassemia major also called cooleys anemia is a serious illness. 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 the mutated gene being inherited by an offspring. May 01, 2004 krishnamurti l, chui dh, dallaire m, leroy b, waye js, perentesis jp. Silent carriers of alpha thalassemia and persons with alpha or beta thalassemia trait are asymp tomatic and require no treatment. Family history and ancestry are factors which increase the risk of beta thalassemia. Normal hemoglobin consists of two alpha chains and two beta chains.
Alpha thalassemia nord national organization for rare. Two types of alpha thalassemia can cause health problems. Alpha mutations, genetic heterogeneity, globin genes, hemoglobin disorders, somatic deletion, splenomegaly. Slide hemoglobin h disease y second most severe form alpha thalassemia. Hemoglobin h disease alpha thalassemia information for physicians and other health care providers definition hemoglobin h disease is an inherited hemoglobin disorder in which three of the four alpha globin genes normally present are deleted or have a mutation which impairs alpha globin chain production. In contrast, gamma globin mutations are evident in the neonate and then disappear as gamma globin synthesis wanes. Normal hemoglobin, also called hemoglobin a, has four protein chainstwo alpha globin and two beta globin.
Beta thalassemia trait and beta thalassemia disease. For example, if one parent has beta thalassemia trait and the other parent has sickle cell trait another type of altered beta globin gene, there is a 25% chance of having a child with sickle beta thalassemia. Alpha thalassemia minor and beta thalassemia minor, also known as alpha thalassemia trait or beta thalassemia trait, are common conditions in many demographics. On the other hand, deletion of three genes results in significant production of hemoglobin h consisting of four beta chain. The child would have a severe form of thalassemia thalassemia major or thalassemia intermedia. This causes a shortage of red blood cells and low levels of oxygen in the bloodstream, leading to a variety of health problems. Introduction to alpha thalassaemia city hospital, birmingham. Disorders of beta globin, such as sickle cell disease and beta thalassemia major, are not clinically apparent until several months of age, when the switch from hemoglobin f to hemoglobin a synthesis. Analysis of the genotype at the alpha and beta loci and testing for the presence of ameliorating genetic factors may be useful in this differentiation see later. Kalpana malla md pediatrics manipal teaching hospital download more documents and. Thalassemia is an inherited blood disorder that reduces the production of functional hemoglobin the protein in red blood cells that carries oxygen. There are two main types, alpha thalassemia and beta thalassemia.
The two main types are called alpha and beta thalassemia, depending on. While the excess beta globin chains are capable of forming soluble homotetramers beta. Treatment of thalassemia major includes regular rbc transfusions. Betathalassemia antonio cao, md1, and renzo galanello, md2. Pdf on mar 21, 2012, vefik arica and others published alpha thalassemia disorders find, read and cite all the research you need on. 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. Thalassemia genetic and rare diseases information center. The alpha chain is involved in alpha thalassemia and the beta chain is affected in the more familiar beta thalassemia. Thalassaemia minor can refer to people with either alpha or beta thalassaemia. When thalassemia is called alpha or beta, this refers to the part of hemoglobin that isnt being made. People who have thalassemias can have mild or severe anemia uhneemeuh. 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. It involves a deficiency of one of the components of hemoglobin, the oxygencarrying molecule in the blood. Guidelines for investigation of the alpha and beta.
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. Key difference alpha vs beta thalassemia thalassemia is a heterogeneous group of disorders caused by inherited mutations that decrease the synthesis of either alpha or beta. Since thalassemia is not a single disorder but a group of related disorders that affect the human body in similar ways, it is important to understand the differences between the various types of thalassemia. Jul 29, 2015 alpha thalassemia is a blood disorder that reduces the bodys production of hemoglobin. Alpha thalassemia trait causes the size of the red blood cells to be smaller than usual. Our primary goal is to help improve the quality of life for all patients with this terrible disease.
We suggest, therefore, that screening programs for heterozygous beta thalassemia in populations where alpha thalassemia is also prevalent, should incorporate the determination of hba2 in the first set of tests. Adult hemoglobin composed two alpha and two beta chains. Med deletion at specifically 875 bp on agarose gel. The two main types are called alpha and beta thalassemias, depending on which part of an oxygencarrying protein called hemoglobin is lacking in the red blood cells. Alpha thalassemia usually caused by gene deletion beta thalassemia usually caused by mutation. A total of 6946 subjects were enrolled for evaluating alphabeta thalassemia from 2012 to 2018. Thalassemia is an inherited blood disorder that is passed down through the parents genes. Thalassemia is due to a deficit or absent production of. Guidelines for investigation of the alpha and beta thalassaemia traits.
The thalassemia support foundation tsf is a nonprofit organization that was founded by patients, parents, and friends affected by thalassemia. The child could be trait in both alpha and beta, or less likely, be disease in one and trait in the other. 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. Automated measurement of red blood cell microcytosis and hypochromia in iron deficiency and beta thalassemia. Describe the clinical and laboratory features of beta thalassemia minor trait and beta thalassemia major and the different types of alpha thalassemia. Diagnosis is typically by blood tests including a complete blood count, special hemoglobin tests, and genetic tests. There are two primary types of thalassemia disease. Physicians often mistake alpha thalassemia trait for iron deficiency anemia and incorrectly prescribe iron supplements that have no effect on the anemia. Three clinical and hematological conditions of increasing severity are recognized. Carrying the gene for alpha plus thalassaemia does not cause any illness, however it.
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