Alpha thalassemia trait may come to the attention of doctors in one of two ways. This discussion will focus on the mechanisms by which the excess unmatched beta globin chain synthesis in alpha thalassemia leads. Alphathalassemia causes, symptoms, diagnosis, treatment. Learn more about its symptoms and how its diagnosed. Treatment for alpha thalassemia depends on the specific type an individual has. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Confirmation of diagnosis is based on molecular genetic testing. Feb 24, 2015 prevention of thalassemia carrier screening thalassemia minor or carrier state can be easily detected in a person by doing simple blood test hba2 by hemoglobin electrophoresis or variant machine or column chromatography prevention includes population education, mass screening, genetic counseling and antenatal diagnosis and therapeutic abortion. Hb bart syndrome is characterized by hydrops fetalis, a condition in which excess fluid builds up in the. Alphathalassemia types, causes, diagnosis, treatment. This means that alpha thalassemia, or a subtype of alpha thalassemia, affects less than 200,000 people in the us population. Alpha thalassemia is a blood disorder that reduces the production of hemoglobin.
Thalassemia trait is commonly detected when routine peripheral blood smear and complete blood count show microcytic anemia and elevated red cell count. Despite the fact that they appeared to have the genotype of hemoglobin h disease, their. Laboratory diagnosis of hemoglobinopathies and thalassemia. Specific treatment for alpha thalassemia will be determined by your childs doctor based on.
However, many people with this type of thalassemia have no signs. Learn more about causes, risk factors, screening and prevention, signs and symptoms, complications, diagnoses. Alpha thalassemia is an inherited anemia where the body is unable to produce a normal amount of hemoglobin. This is called the cis form of alpha thalassemia trait. Hematological tests being recessive condition, recognition of carriers, is essential and possible by hematological tests. Your childs age, overall health, and medical history. Know what are the signs and symptoms of thalassemia in adults. The majority of the a thalassemia defects result from deletions involving one or both aglobin genes in cis, resulting in. Clinical manifestations and diagnosis of the thalassemias uptodate. Thalassemia is a group of inherited blood disorders passed on through genes that can affect hemoglobin production and cause anemia. The pathogenesis and treatment of alpha and beta thalassemia.
If desired, the diagnosis of beta thalassemia trait can be confirmed with quantitative hemoglobin studies. Laboratory diagnosis of thalassemia brancaleoni 2016. Alpha thalassemia typically results from deletions involving the hba1 and hba2 genes. There are different types, which vary from a mild condition with no symptoms, to a serious or lifethreatening condition.
It is caused by either a genetic mutation or a deletion of certain key gene fragments. Thalassemia results when mutations affecting the genes involved in hb biosynthesis lead to decreased hb production. Like all common globin gene disorders sickle cell trait and. Silent carrier, alpha thalassemia trait, hemoglobin h disease, hemoglobin hconstant spring, and. Mutations may overlap on the screening test, resulting in incorrect diagnosis or a false negative. Hemoglobin electrophoresis is used to diagnose beta thalassemia. Like the silent carrier, alpha thalassemia trait is not a disease and does not. Beta thalassemia causes, symptoms, diagnosis, treatment, pathology duration. Genetic services in hawaii are provided by board certi. In people with the characteristic features of alpha thalassemia, a reduction in. People who have this condition can pass the disease on to their children.
There are at least 4 different and distinct alpha thalassemias. Beta thalassemia minor, which is a mild, nontransfusion dependent anemia is caused by a defect in one copy of the beta gene. Alpha thalassemia is caused by alpha globin gene deletion which results in reduced or absent production of alpha globin chains. Jan 19, 2017 know what are the signs and symptoms of thalassemia in adults. Started in 1995, this collection now contains 6767 interlinked topic pages divided into a tree of 31 specialty books and 732 chapters. The prevention and control of thalassemia in thailand focus on the appropriate diagnosis with a simple, cheap, and practical tool for any staff to use.
Thalassemia is a group of inherited blood disorders caused by defects in one or more genes responsible for producing the globin chains in hemoglobin. Alpha thalassemia major with hemoglobin barts usually results in fatal hydrops fetalis. An adult with hbh disease shows hbh, visible as inclusion bodies as a minor peak on hplc or capillary electrophoresis during routine hb analysis. Thalassemia is a genetic blood disorder that impacts the ability of the blood to get oxygen to the bodys organs. Hb h disease, which causes mild to moderately severe anemia, and an enlarged spleen the organ that removes abnormal red blood cells from circulation alpha thalassemia major is the most severe type. Thalassaemia usually requires lifelong treatment with blood transfusions and medication. Prior to consideration of transfusion therapy, it is critical to confirm the patients diagnosis. Fetuses with hemoglobin bart typically do not survive beyond the newborn per. Most cases of hemoglobin variants and alpha thalassemia are detected on the newborn screen, whereas beta thalassemia is not clinically apparent until about 46 months of life. Therefore, genetic analysis for both betathalassemia and alpha thalassemia. Alpha thalassemia is a fairly common blood disorder worldwide. Prenatal diagnosis is determined from cvs chorionic villus sampling or amniocentesis. Dna analysis on chorionic villi is the approach for prenatal diagnosis and the methods are the same used for mutations detection, according to the laboratory facilities and expertise. Thalassemia minor also called thalassemia trait may cause no symptoms, but mild anemia and other changes in the blood do occur.
Thalassemias national heart, lung, and blood institute. Alphathalassemia types, causes, diagnosis, treatment and. Hemoglobin a the major hemoglobin in adults contains two alpha globin chains and two beta globin chains. Carriers may experience mild anemia or no symptoms at all. Alpha thalassemia intermedia, or hemoglobin h disease, causes hemolytic anemia. The main types of thalassaemia are called alpha thalassaemia and beta thalassaemia. Genetic testing is used to make a diagnosis of alpha thalassemia. Alpha thalassemia is a type of thalassemia that is inherited passed down through families. Alpha thalassemia symptoms, diagnosis, treatments and causes. Two types of alpha thalassemia can cause health problems. Alpha thalassemia is an autosomal recessive disorder caused by deletion of alpha globin genes on chromosome 16. When both parents have alpha thalassemia trait, there usually is a 25% or 1 in 4 chance in each pregnancy for the baby to have alpha. An individual with one abnormal alpha globin gene is said to be a silent carrier of alpha thalassemia.
Learn about signs and symptoms and the laboratory tests used to help diagnose thalassemia. Alphathalassemia information sheet integrated genetics. Jul 29, 2015 alpha thalassemia is a blood disorder that reduces the bodys production of hemoglobin. Thalassemias are inheritedthat is, the genes for the disorders are passed from parents to their children. For instance, a diagnosis of thalassemia major entails lifelong reg ular transfusion requirement for. Hawaii community genetics provides pediatric and adult clinical genetic services. The program is designed to address the complex diagnostic, prenatal, intrauterine, and perinatal management issues affecting a family with an alpha thalassemia major pregnancy. For the more severe forms of thalassaemia, modern treatment gives a good outlook, but lifelong monitoring and treatment are needed. Alpha thalassemia also occurs frequently in people from mediterranean countries, africa, the middle east, india, and central asia. The trans and cis types of alpha thalassemia trait are found most often in people whose ancestors come from southeast asia, southern china, the mediterranean, and the middle east. Diagnosis of beta thalassemia minor is confirmed by hba2 3. Alpha thalassemia also has two serious categories, which. The importance of hemoglobin a2 determination scielo.
A blood disorder, thalassemia is not one disease but rather a group of disorders that have a single feature in common. Thalassemia womens and infants health at mount sinai. If the diagnosis of thalassemia or hemoglobinopathy is apparent based on hemoglobin studies and there are no genetic counseling issues, additional genetic testing is generally not needed. Alpha thalassemia involves defects in one or more of the four genes required to make each. Pdf on mar 21, 2012, vefik arica and others published alpha thalassemia. Fractions of hemoglobin a, a2, f, h, e, and other variants are measured. It includes alpha thalassemia and beta thalassemia. Carrier screening to help detect the risk of having a baby with a specific inherited disorder, such as cystic fibrosis. Alpha thalassemia is a general term for a group of inherited blood disorders characterized by reduced or absent production of alpha globin subunits, resulting in low levels of hemoglobin that is otherwise fully functional. Thalassemia is an inherited disease, meaning that at least one of the parents must be a carrier for the disease. Thalassemia quantitative a quantitative decrease in the production of alpha or beta globin chain large deletions, point mutations, small insertiondeletion that leads to decreased transcription or an unstable transcript beta thalassemia results from mutations in beta genes pathogenesis a result of the free alpha subunits. Laboratory diagnosis oflaboratory diagnosis of thalassemia. Signs and symptoms of thalassemia in adults care whizz.
Hemoglobin is an ironrich protein in red blood cells that carries oxygen to cells throughout the body. Each type of thalassaemia alpha and beta is then classified into more types, according to how severe the condition is. 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. There are at least 4 different and distinct alphathalassemias. If your parents have missing or altered hemoglobinmaking genes, you may have thalassemia. Thalassemias are inherited blood disorders, causing the body to make fewer healthy red blood cells and less hemoglobin than normal. Thalassemia knowledge for medical students and physicians. Hemoglobin is the protein in red blood cells that carries oxygen to cells throughout the body. An acquired form known as alpha thalassemia myelodysplastic syndrome atmds. Children and adults with thalassaemia will be supported by a team of different healthcare professionals working together at a specialist thalassaemia centre. Aug 28, 20 alphathalassemia is one of the two forms of the life threatening blood disease known as thalassemia. An algorithm for the use of molecular diagnostic testing for individuals with hemoglobin abnormalities. The analysis of the hemoglobin molecule with electrophoretic methods is an important laboratory test, which sometimes offers a definite diagnosis of the thalassemia. Maternity alpha thalassemia diagnosis and treatment.
An individual with two abnormal alpha globin genes is said to have alpha thalassemia trait. Aug 01, 2009 alpha thalassemia occurs frequently in people from mediterranean countries, north africa, the middle east, india, and central asia. Or you may have mild symptoms such as mild fatigue or exercise intolerance. The ucsf fetal treatment center and ucsf benioff childrens hospitals have established the first multidisciplinary center for alpha thalassemia major. Different people will have different symptoms, based on which type of alpha thalassemia is inherited. Definitive diagnosis of thalassemia and hemoglobinopathies requires a comprehensive workup from complete blood count, hemoglobin analysis, and molecular studies to identify mutations of globin genes. The alpha and beta refer to which haemoglobin gene is affected, and which of the haemoglobin chains is faulty. Molecular diagnosis of thalassemias and hemoglobinopathies. Laboratory diagnosis oflaboratory diagnosis of thalassemia yneed to start with patients individual history and familyyy history. Your healthcare team will help you learn more about thalassaemia and work with you to come up with. Alpha thalassemia nord national organization for rare.
Alphathalassemia is one of the two forms of the life threatening blood disease known as thalassemia. Aug 09, 2019 the increase in number of patients with thalassemia living in california highlights the importance of provider knowledge about thalassemia in order to effectively serve these patients in their communities. Thalassaemia thalassaemia is an inherited condition affecting the blood. This condition, in which one of the four alpha globin genes is missing or defective, generally causes no health problems because the lack of alpha globin protein is so small that there is no anemia. Silent carriers of alpha thalassemia and persons with alpha or beta thalassemia trait are asymp tomatic and require no treatment. It is a blood disorder that reduces how well the body produces healthy red blood cells and normal hemoglobin. Thalassemia is a blood disorder in which the body makes an abnormal form of hemoglobin. Anyone can be a carrier of thalassaemia, but its much more common in people from certain ethnic backgrounds. Laboratory diagnosis of hemoglobinopathies and thalassemia medical director, hematopathology and rbc laboratory arup laboratories assistant professor of pathology university of utah department of pathology archana m agarwal, md. The molecular diagnosis is essential to predict severe transfusion. Diagnosis most persons with thalassemia trait are found incidentally when their complete blood count shows a 10mild microcytic anemia. The clinical phenotype results from both the diminished amount of the particular globin chain as well as from the resultant chain imbalance that occurs because of normal production of the other globin chain.
Both aorb thalassemia carriers heterozygotes present. Thalassemias national heart, lung, and blood institute nhlbi. Compound heterozygotes and some homozygotes have a moderate to severe form of alpha thalassaemia called hbh disease. Thalassemia is an inherited blood disorder characterized by abnormal synthesis of hemoglobin. This discussion will focus on the mechanisms by which the excess unmatched beta globin chain synthesis in alpha thalassemia leads to increased red blood cell destruction hemolysis. The main symptom is anemia, the severity of which can vary amongst patients depending on how many defective genes are involved. Pdf clinical classification, screening and diagnosis for.
Alpha thalassemia is a group of disorders of hemoglobin synthesis, caused by mutations or deletions in at least 1 of the 4 alpha globin genes, leading to variably impaired alpha globin chain production, with accumulation of the now excess and unpaired betaglobin chains. Its causes, risk factors, complications and what are the treatment options for thalassemia. More detailed information about the symptoms, causes, and treatments of alpha thalassemia is available below. People with alpha thalassemia trait do not develop hemoglobin h disease or hydrops fetalis later in life.
Your symptoms will depend on the category of thalassemia you have. Affected people have anemia, which can cause pale skin, weakness, fatigue, and more serious complications. Some children with alpha thalassemia have no symptoms and require no treatment. A person with two working copies of the alpha globin gene has alpha thalassemia trait. Alphathalassemia genetic and rare diseases information. Harteveld and higgs 2010, so why should we take the opportunity to revisit this topic.
Abnormal pattern depends on the exact subtype see table with hemoglobin variants. Others with more severe cases need regular blood transfusions to treat. Most children with thalassemia major appear healthy at birth but, during the first year or two of life, they become. It causes the body to make less hemoglobin than normal. Thalassemia is a type of thalassemia that is caused by a deficiency of the alpha globin protein. An alpha thalassemia trait that can cause mild anemia. Efficiency assessment of immunochromatographic strip test. Thalassemia can occur in all ethnic groups but is more common in those of southeast asian descent. In alpha thalassemia, there is a reduced amount of alpha globes. Read on to know all about its various types, symptoms and possible treatment options. Source national institutes of health nih ophanet, a consortium of european partners, currently defines a condition rare when it affects 1 person per 2,000. The alpha thalassemias can be generally categorized as. The two abnormal genes can be on the same chromosome or on each chromosome in the pair.
Thalassemias occur most often among people of italian, greek, middle eastern, southern asian, and african descent. 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. People who have alpha thalassemia trait can have mild anemia. Differential diagnosis differential diagnosis should include iron deficiency anemia and defects in heme synthesis. All of these studies can be performed from a single blood sample. They are characterized by reduced or absent production of 1 or more of the globin chains of which human hemoglobin is composed. Hemoglobin analysis by hemoglobin electrophoresis or high performance liquid chromatography is used. In addition to complete blood count cbc, hemoglobin electrophoresis is the first diagnostic test. The absence ofthe absence of hb h inclusions therefore does not excludeh inclusions therefore does not exclude thalassemia trait, but the presence of typical inclusions may be helpful in confirming a presumptive diagnosis. Thousands of infants with hb bart syndrome and hbh disease are born each year, particularly in southeast asia. The nhs sickle cell and thalassaemia screening programme also has detailed leaflets about being a beta thalassaemia carrier pdf, 804kb or a delta beta thalassaemia carrier pdf, 779kb. This condition causes mild to severe anemia, based on the type of alpha thalassemia that is inherited. In people with the characteristic features of alpha thalassemia, a reduction in the amount of hemoglobin prevents enough oxygen from reaching the bodys tissues.
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