People have two copies of the hba1 gene and two copies of the hba2 gene in each cell. Carrier frequencies of betathalassemia vary from 1% to. The alpha and beta refer to which haemoglobin gene is affected, and which of the haemoglobin chains is faulty. If either the alpha or beta part is not made, there arent enough building blocks to make normal amounts of hemoglobin. The types are alpha thalassemia major, hemoglobin h disease, and 2 forms of alpha thalassemia carrier. Treatment depends on the type of alpha thalassemia. Alpha thalassemia is a general term for a group of inherited blood disorders characterized by reduced or absent production of alphaglobin subunits, resulting in low levels of hemoglobin that is otherwise fully functional. Laboratory diagnosis oflaboratory diagnosis of thalassemia.
It usually appears during the first two years of life. They are characterized by reduced or absent production of 1 or more of the globin chains of which human hemoglobin is composed. For language access assistance, contact the ncats public information officer. Adult hemoglobin hemoglobin a is made of alpha and beta globins. This condition, in which one of the four alpha globin genes is missing or. Thalassemias are a group of inherited blood conditions which result in the impaired production of hemoglobin, the molecule that carries oxygen in the blood. It is owing to either a genetic mutation or an obliteration of certain key gene fragments. Results in microcytic, hypochromic anemias of varying severity. 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. Aug 28, 20 alphathalassemia is one of the two forms of the life threatening blood disease known as thalassemia. Therefore, there are 4 alleles that produce alpha globin, the protein that results from these genes. Alpha thalassemia thal uh see mee uh trait is a condition that affects the amount of hemoglobin in the red blood cells.
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. When there isnt enough hemoglobin, the bodys red blood cells dont function properly and they last shorter periods of time, so there are fewer healthy red blood cells traveling. Alphathalassemia types, causes, diagnosis, treatment and. The most common severe type in the united states is called cooleys anemia. Alphathalassemia genetic and rare diseases information. Alpha thalassemia should not be treated with iron because it will not help. Along with patient care, medical research is a primary focus at the comprehensive thalassemia center at ucsf benioff childrens hospital oakland. Screening for alpha thalassemia is focused on prenatal counseling and diagnosis and on newborn screening. Thalassemia research and care at ucsf benioff childrens hospital oakland.
Thalassemias are a group of inherited blood conditions which result in the impaired production of hemoglobin, which is the molecule that carries oxygen in. Alpha thalassemia major is almost uniformly fatal in utero without intervention. Signs and symptoms of thalassemia in adults care whizz. Silent carrier 2 trait a l p h a t h a lassemia 1 trait results from deletions of 2 of the alpha gene and commonly is a subclinical anemia. For each of the 2 genes, one allele is inherited from a persons father, and.
In alphathalassemia, at least one of the alpha globin genes has a mutation or aberration. People with hemoglobin h disease can have an enlarged spleen, low red blood. Normally, people have 4 genes for alpha globin with 2 genes on each chromosome aaaa. 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. Thalassemias involving delta, gamma, epsilon, and zeta chains are rare and usually not associated with significant disease outside of the neonatal period. The pathogenesis and treatment of alpha and beta thalassemia. Alpha thalassemia is a blood disorder that reduces the production of normal hemoglobin, the protein in red blood cells that carries oxygen to cells throughout the body there are four types of alpha thalassemia, hemoglobin bart hydrops fetalis syndrome or hb bart syndrome the more severe form, hbh disease.
Thalassemia hematology american society of hematology. Each type of thalassaemia alpha and beta is then classified into more types, according to how severe the condition is. Laboratory diagnosis of hemoglobinopathies and thalassemia. Couples at risk for alpha thalassemia in pregnancy have the option to pursue prenatal diagnosis to determine if their fetus has alpha thalassemia major. Alphathalassemia types, causes, diagnosis, treatment. The more severe forms of alphathalassemia are found in southeast asians glader and look, 1996 and less commonly in infants of mediterranean origin. Alphathalassemia is one of the two forms of the life threatening blood disease known as thalassemia. Individuals who have one or two abnormal alpha globin genes have alpha thalassemia trait. 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 with alpha thalassemia trait can have small red blood cells and a low red blood cell count mild anemia. Potential fetal therapies are available, including transfusing the developing fetus with red blood cells to. They characterised by varying degrees of ineffective hematopoiesis and increased hemolysis icd classification. The most severe form of alpha thalassemia, alpha thalassemia disease alpha thalassemia major can only happen when both parents have alpha thalassemia trait.
This signs and symptoms information for alpha thalassemia has been gathered from various sources, may not be fully accurate, and may not be the full list of alpha thalassemia signs or alpha thalassemia symptoms. We have relied on accessory clues for the condition using the biorad d10bts program. In most cases, alpha thalassemia is diagnosed before a childs second birthday or through newborn screening, a blood test given when the child is first born. Deletional forms result in a relatively mild anemia, whereas nondeletional. What if one parent has alpha thalassemia trait and the other parent is a silent carrier. Alpha thalassemia can be treated with iron only if the person has low iron.
Jul 29, 2015 alpha thalassemia is a blood disorder that reduces the bodys production of hemoglobin. 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. Alpha thalassemia alpha thalassemia is the result of changes in the genes. Alpha globin is made by four genes, two on each strand of chromosome 16. Thalassaemia major genetics of thalassemia adult hemoglobin composed two alpha and two beta chains. This condition causes mild to severe anemia, based on the type of alpha thalassemia that is inherited. Slide hemoglobin h disease y second most severe form alpha thalassemia. If you have problems viewing pdf files, download the latest version of adobe reader. The term thalassemia is derived from the greek words thalassa sea and haema blood and refers to disorders associated with defective synthesis of. Thalassemia stock photos download 622 royalty free photos. Pdf clinical classification, screening and diagnosis for. People who are carriers of a thalassemia gene show no thalassemia symptoms and might not know theyre carriers. Alphathalassemia is usually inherited in an autosomal recessive manner. Thousand oaks california hematologist doctors physician directory read about thalassemias alpha, inherited blood disorders with symptoms such as anemia, slowed growth, bone problems, enlarged spleen, jaundice, poor appetite, and more.
In people with the characteristic features of alpha thalassemia, a reduction in. Thalassemia thalassemia is an inherited blood disorder in which the body produces an abnormal form of hemoglobin which results in excessive destruction of red blood cells and further leads to anemia. 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. The hematological parameters including red cell indices and morphology, followed by separation and measurement of hb fractions are the basis for the identi. There are two primary types of thalassemia disease. Thalassemias slide 1 by the end of the lecture, the student.
Carrier frequencies of beta thalassemia vary from 1% to 5% while prevalence data for alpha thalassemia are scant. Prenatal diagnosis for alpha thalassemia major is usually done by either chorionic villus sampling cvs, performed between10 weeks and 14 weeks of gestation, or by amniocentesis, performed. Screening for alphathalassemia is focused on prenatal counseling and diagnosis and on newborn screening. People who have this condition can pass the disease on to their children. Thalassaemia disorders in humans caused by the deficiency of the alpha chain of hemoglobin have been well documented and validated throughout the world, by various stepwise diagnostic strategies and techniques. Molecular diagnosis of thalassemias and hemoglobinopathies. Carriers may experience mild anemia or no symptoms at all. Definition thalassemia is a group of inherited disorders of hemoglobin synthesis characterized by a reduced or absent one or more of the globin chains of adult hemoglobin. Alphathalassemia is of particular importance to neonatologists because its clinical manifestations are present in utero and at birth. Alphathalassemia is due to impaired production of alpha chains from 1, 2, 3, or all 4 of the alpha globin genes, leading to a relative excess of beta globin chains. Beta thalassemia major also called cooleys anemia is a serious illness.
The condition is caused by the disruption of one or more of the four resident homologous hemoglobin alpha genes. Two types of alpha thalassemia can cause health problems. Alphathalassemia is one of the most common hemoglobin genetic abnormalities and is caused by the reduced or absent production of the alpha globin chains. Thalassemia is a type of thalassemia that is caused by a deficiency of the alpha globin protein. The two main forms of thalassemia are alphathalassemia and betathalassemia. Genetic studies dna analysis to investigate deletions and mutations in the alpha and betaglobinproducing gene help in correct diagnosis and improved management in thalassemic patients. Alpha thalassemia 2 trait, also called the silent carrier is an asymptomatic carrier of a single alpha gene deletion. More than 200 deletions or point mutations that impair. Symptoms appear in the first two years of life and include paleness of the skin, poor appetite, irritability, and failure to grow. The flow chart shown in fig 4 summarizes the techniques for diagnosis of thalassemia and. This material may not otherwise be downloaded, copied, printed. Alpha thalassemia is caused by reduced or absent synthesis of alpha globin chains, and beta thalas. Hemoglobin h disease results from mutations of three aglobin genes.
Treatment for alphathalassemia depends on the specific type an individual has. When thalassemia is called alpha or beta, this refers to the part of hemoglobin that isnt being made. Alpha thalassemia major atm occurs when all four genes are nonfunctioning. The molecular basis for alphathalassemia is usually deletion of one or more of the four alpha globin genes. In people with the characteristic features of alpha thalassemia, a reduction in the amount of hemoglobin prevents enough oxygen from reaching the bodys tissues. Three clinical and hematological conditions of increasing severity are recognized. Alpha thalassemia trait normally does not cause any health problems. Thousand oaks ca hematologist doctors alpha thalassemia. Silent carriers of alpha thalassemia and persons with alpha or beta.
Alpha thalassemia intermedia, or hemoglobin h disease, causes. Two types of alphathalassemia can cause health problems. Read on to know all about its various types, symptoms and possible treatment options. While the excess beta globin chains are capable of forming soluble homotetramers beta4, hbh, they are. Its caused by changes in the genes that control the production of hemoglobin. Affected people have anemia, which can cause pale skin, weakness, fatigue, and more serious complications.
Alphathalassemia is a blood disorder that reduces the bodys production of hemoglobin. Aug 01, 2009 alpha thalassemia is a blood disorder that reduces the production of normal hemoglobin. 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 use of intrauterine transfusions to sustain the viability of fetuses with homozygous alpha thalassemia has created a new population of patients with severe thalassemia and has raised new and complex issues in genetic counseling for parents with alpha thalassemia trait. Thalassemia is a group of inherited blood disorders caused by defects in one or more genes responsible for producing the globin chains in hemoglobin.
Children with alpha thalassemia major may have a swollen abdomen or symptoms of anemia or failure to thrive. It causes the body to make less hemoglobin than normal. Sep 14, 2010 the standard practice of excluding iron deficiency and beta thalassemia and using cell counter indices as a marker for alpha thalassemia remains the first step to ascertaining alpha globin deficiencies followed by support of hplc and electrophoresis procedures. Download 622 thalassemia stock photos for free or amazingly low rates. Genetic counseling and pregnancy testing patients with the appropriate ethnic background i. Alpha thalassemia disease and beta thalassemia disease. Apr 03, 2018 thalassaemia major genetics of thalassemia adult hemoglobin composed two alpha and two beta chains. In alpha thalassemia, at least one of the alpha globin genes has a mutation or abnormality. The symptom information on this page attempts to provide a list of some possible signs and symptoms of alpha thalassemia.
Beta thalassemia major is a clinical diagnosis referring to a patient who has a severe form of the disease and requires chronic transfusions early in life. Genetic and rare diseases information center gard po box 8126, gaithersburg, md 208988126 tollfree. Alpha and beta thalassemia american family physician. 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. The main types of thalassaemia are called alpha thalassaemia and beta thalassaemia. Alpha thalassemia is a blood disorder that reduces the production of hemoglobin. Thalassemias slide 1 by the end of the lecture, the. Alpha thalassemia nord national organization for rare. Normal hemoglobin consists of two alpha chains and two beta chains. An individual with one abnormal alpha globin gene is said to be a silent carrier of alpha thalassemia. Pdf on mar 21, 2012, vefik arica and others published alpha thalassemia disorders find, read and cite all the research. Thalassemia in arab populations alpha and betathalassemia are endemic in almost all arab countries probably due to the historical presence of malaria in the region and the high level of consanguinity.
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