Materiały źródłowe

• #1 Thalassemia: Types, Traits, Symptoms & Treatment

  https://my.clevelandclinic.org/health/diseases/14508-thalassemias

  Thalassemia is an inherited blood disorder that affects your bodys ability to produce hemoglobin and healthy red blood cells. […] The gene mutations that cause thalassemia arose in humanity as partial protections against malaria. […] Hemoglobin consists of four protein chains, two alpha globin chains and two beta globin chains. Each chain both alpha and beta contains genetic information, or genes, passed down from your parents. […] If any of these genes are defective or missing, youll have thalassemia. […] The thalassemia you have depends on whether your alpha or beta chain contains the genetic defect. The extent of the defect will determine how severe your condition is. […] Thalassemia is classified as trait, minor, intermedia and major to describe how severe the condition is. […] You inherit four genes, two from each parent, that make alpha globin protein chains. When one or more genes are defective, you develop alpha thalassemia.

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  https://www.nhs.uk/conditions/thalassaemia/

  Thalassaemia is caused by faulty genes that affect the production of haemoglobin. […] A child can only be born with thalassaemia if they inherit these faulty genes from both parents. […] The parents of a child with thalassaemia are usually carriers. This means they only have 1 of the faulty genes.

• #1 Thalassemia – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK545151/

  Thalassemia is autosomal recessive, which means both the parents must be affected with or carriers for the disease to transfer it to the next generation. It is caused by mutations or deletions of the Hb genes, resulting in underproduction or absence of alpha or beta chains. There are over 200 mutations identified as the culprits for causing thalassemias. Alpha thalassemia is caused by deletions of alpha-globin genes, and beta thalassemias are caused by a point mutation in splice site and promoter regions of the beta-globin gene on chromosome 11. […] Thalassemias are a heterogeneous grouping of genetic disorders that result from a decreased synthesis of alpha or beta chains of hemoglobin (Hb). Hemoglobin serves as the oxygen-carrying component of the red blood cells. It consists of two proteins, an alpha, and a beta. If the body does not manufacture enough of one or the other of these two proteins, the red blood cells do not form correctly and cannot carry sufficient oxygen; this causes anemia that begins in early childhood and lasts throughout life. Thalassemia is an inherited disease, meaning that at least one of the parents must be a carrier for the disease. It is caused by either a genetic mutation or a deletion of certain key gene fragments.

• #1 Thalassemia – Causes | NHLBI, NIH

  https://www.nhlbi.nih.gov/health/thalassemia/causes

  Thalassemia is an inherited blood disorder that causes your body to produce less hemoglobin than normal. […] Thalassemia develops when faulty genes prevent your body from making the right amount of alpha globin or beta globin chains. […] If you inherit faulty genes from both parents, your disease may be moderate to serious. […] You need four genes (two from each parent) to make enough alpha globin protein chains. […] If one or more of the genes is missing, you will have alpha thalassemia, which means your body does not make enough alpha globin protein. […] You need two genes (one from each parent) to make enough beta globin protein chains. […] If one or both of these genes are altered, you’ll have beta thalassemia. […] If your parents have mutations in the alpha globin or beta globin genes, or in other genes that affect the alpha or beta globin protein chains, then you can inherit thalassemia. […] Thalassemia occurs most often among people of South Asian, Italian, Greek, Middle Eastern, and African descent. […] Since thalassemia is caused by changes (mutations) in genes, there is no way to prevent it.

• #1 Alpha Thalassemia Treatment | St. Jude Care & Treatment

  https://www.stjude.org/care-treatment/treatment/blood-disorders/alpha-thalassemia.html

  If 1 gene is affected, a person is a silent carrier of alpha thalassemia. This person usually does not have symptoms. […] If 2 genes are affected, a person has alpha thalassemia trait. This condition is also called alpha thalassemia minor. This person may have mild anemia which can look like mild iron-deficiency anemia. […] If 3 genes are affected, a person has hemoglobin H disease. This disease can cause moderate anemia. […] If all 4 genes are affected, a person has alpha thalassemia major. You may hear this called hydrops fetalis. This is the most severe type of alpha thalassemia. The body cannot make enough healthy hemoglobin to carry oxygen as needed. An unborn baby with this disorder will usually die in the womb or soon after birth unless a blood transfusion is given before the baby is born.

• #1 Beta Thalassemia: Practice Essentials, Etiology, Epidemiology

  https://emedicine.medscape.com/article/206490-overview

  Beta thalassemia is due to mutations in one or both of the beta-globin genes that result in impaired synthesis of the beta-globin protein component of Hb, and subsequently in anemia. […] More than 350 beta-globin gene mutations have been identified in patients with beta thalassemia; this underlies the wide genotypic and phenotypic variability of the disease. […] Beta thalassemia is inherited as an autosomal recessive disorder. […] The defect can be a complete absence of the beta-globin protein (ie, beta-zero thalassemia) or a severely reduced synthesis of the beta-globin protein (ie, beta-plus thalassemia). […] The genetic defect usually is a missense or nonsense mutation in the beta-globin gene. […] In beta thalassemia intermedia the production of beta-globin chains is variably decreased.

• #1 Beta Thalassemia: Types, Symptoms & Treatment

  https://my.clevelandclinic.org/health/diseases/23574-beta-thalassemia

  Beta thalassemia results from a mutation (error) that limits beta-globin production in your body. […] Mutations of the alpha-globin chain cause alpha thalassemia, while mutations of the beta-globin chain cause beta thalassemia. […] You inherit the gene mutation for beta thalassemia in an autosomal recessive pattern. […] In rare instances, inheriting just one mutated beta-globin gene causes beta thalassemia. […] The number of defective genes you inherit and the mutations location will determine your conditions severity. […] Some mutations cause no beta-globin to be produced (beta-zero thalassemia). […] Other mutations cause too little beta-globin to be made (beta-plus thalassemia). […] Beta thalassemia major (Cooleys anemia) is the most severe kind of beta thalassemia. […] Beta thalassemia intermedia may cause mild to moderate anemia symptoms. […] Beta thalassemia minor (beta thalassemia trait) often causes mild anemia symptoms.

• #1 Diagnosis of thalassemia (adults and children) – UpToDate

  https://www.uptodate.com/contents/clinical-manifestations-and-diagnosis-of-the-thalassemias

  The thalassemias are a group of hemoglobinopathies in which the normal ratio of alpha globin to beta globin production is disrupted due to a genetic variant in one or more alpha or beta globin genes. This abnormal alpha chain to beta chain ratio causes the unpaired chains to precipitate, leading to destruction of red blood cell (RBC) precursors in the bone marrow (ineffective erythropoiesis) and in the circulation (hemolysis). Individuals with thalassemia have variable degrees of anemia and extramedullary hematopoiesis, which in turn can cause bone changes, impaired growth, and iron overload. […] The pathogenesis and treatment of thalassemia, including the role of hematopoietic stem cell transplantation, monitoring of iron stores, and iron chelation, are discussed in detail separately.

• #1 Thalassemia: Pathophysiology, Diagnosis, and Advances in Treatment

  https://www.mdpi.com/2039-4365/14/4/10

  Thalassemia represents a diverse group of inherited hematological disorders characterized by defective globin chain synthesis, leading to chronic anemia and associated complications. The complicated pathophysiology of beta-thalassemia involves genetic mutations or rarely deletions of the beta-globin gene on chromosome 11 whereas alpha-thalassemia involves deletions in the HBA1 and HBA2 genes or occasionally alterations to the DNA sequence in or around these genes. […] The genetic basis of thalassemia involves mutations that affect the expression of globin genes, particularly the β-globin gene, resulting in reduced or absent synthesis of β-globin chains. […] The pathophysiology of thalassemia involves a disruption in the balance of globin chain synthesis, leading to an imbalance in the alpha- and beta-globin chains and subsequent abnormalities in red blood cell formation and function.

• #1 Thalassemia: MedlinePlus Medical EncyclopediaLock

  https://medlineplus.gov/ency/article/000587.htm

  Thalassemia is a blood disorder passed down through families (inherited) in which the body makes an abnormal form or inadequate amount of hemoglobin. […] Thalassemia occurs when there is a variant in a gene that helps control production of one of these proteins. […] There are two main types of thalassemia: Alpha thalassemia occurs when a gene or genes related to the alpha globin protein are missing or there is a variant. […] Beta thalassemia occurs when similar gene defects affect production of the beta globin protein. […] Risk factors for thalassemia include: Asian, Chinese, Mediterranean, or African American ethnicity; Family history of the disorder.

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• #1 Thalassemia – Wikipedia

  https://en.wikipedia.org/wiki/Thalassemia

  The thalassemias are classified according to which chain of the hemoglobin molecule is affected. In -thalassemias, production of the -globin chain is affected, while in -thalassemia, production of the -globin chain is affected. […] The prevalence has increased in previously non-endemic areas as a consequence of historical and recent immigration flows, slave-trade, trading activities and colonization. […] It is believed that carriers of thalassemia are protected against malaria and that natural selection is responsible for elevating and maintaining their gene frequencies.

• #1 Thalassaemia | Better Health Channel

  https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/thalassaemia

  Thalassaemia is the most common inherited blood condition in the world. This condition is caused by changes to the genes for haemoglobin. […] Changes affecting haemoglobin result in severe anaemia. […] There are two different types of thalassaemia: alpha (a) and beta (b). Alpha-thalassaemia involves genetic changes in two genes (HBA1 and HBA2). Beta-thalassaemia involves changes in one gene (HBB). […] If two people who are carriers of the same type of thalassaemia have children, their children have a: 25 per cent risk of developing thalassaemia major because they inherited the thalassaemia gene from both parents. […] Thalassaemia can be diagnosed through blood tests and genetic testing. […] It is suggested that all couples thought to be at risk be tested for thalassaemia carrier status, especially before starting a family. […] Genetic counsellors are health professionals qualified in both counselling and genetics. […] They can help you to understand thalassaemia and what causes it, how it is inherited, and what a diagnosis means for your child’s health and development.

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  https://www.nhs.uk/conditions/thalassaemia/causes/

  Thalassaemia is caused by faulty genes that a child inherits from their parents. […] It’s not caused by anything the parents did before or during the pregnancy, and you cannot catch it from someone who has it. […] To be born with the main type of thalassaemia, beta thalassaemia, a child has to inherit a copy of the faulty beta thalassaemia gene from both of their parents. […] This usually happens when both parents are „carriers” of the faulty gene, also known as having the „thalassaemia trait”. […] Another type of thalassaemia, alpha thalassaemia, has a more complex inheritance pattern because it involves 4 potentially faulty genes, rather than just 2. […] Children of parents who are carriers of the alpha thalassaemia trait will be born with the condition if they inherit 3 or 4 copies of the faulty gene.

• #1 Thalassemia: Types, Causes, Symptoms & Treatment | Medanta

  https://www.medanta.org/pillar/thalassemia-types-symptoms-causes-diagnosis-treatment

  Thalassemia is inherited in an autosomal recessive pattern, meaning that for a child to have thalassemia, both parents must carry and pass on the mutated gene. If only one parent passes on the gene, the child will be a carrier and may not show disease symptoms. […] The primary risk factor for thalassemia is having a family history of the disease. If both parents are carriers of the thalassemia gene, their children have a 25% chance of having the disease. Ethnic background also plays a significant role, with individuals from Mediterranean, South Asian, Southeast Asian, and Middle Eastern ancestries at higher risk. […] Thalassemia major is a preventable disease. Genetic counselling and prenatal testing can help at-risk couples assess their likelihood of having a child with the condition.

• #1 What is Thalassemia? | CAF

  https://thalassemia.org/What-is-Thalassemia

  This is the most severe form of Beta Thalassemia in which the complete lack of beta protein in the hemoglobin causes a life-threatening anemia that requires regular blood transfusions and extensive ongoing medical care. […] People whose hemoglobin does not produce enough alpha protein have Alpha Thalassemia. […] Alpha Thalassemia occurs when the body doesnt produce enough alpha protein in hemoglobin, commonly affecting people in Africa, Asia, and the Mediterranean. […] In addition to the Alpha and Beta Thalassemias, there are other related disorders that occur when the gene for alpha or Beta Thalassemia combines with an abnormal or mutant gene.

• #1 Thalassemia: Causes, Symptoms, Diagnosis – SelfDecode Health

  https://health.selfdecode.com/blog/thalassemia/

  Delta-thalassemia is a very rare mutation in the delta subunit gene (HBD gene). Since the hemoglobin-containing delta subunits only make up 2.5% of total hemoglobin, mutations in this gene are not severe. However, delta-thalassemia can occur with beta-thalassemia. […] Research suggests that changes in hemoglobin genes may increase the risk of developing other genetic conditions like osteoporosis.

• #1 Thalassemia: Types, Symptoms, Diagnosis, and More

  https://www.verywellhealth.com/thalassemia-7556880

  Thalassemia usually is an inherited condition, but in some instances, it can be acquired, usually in a person with a type of blood cancer. […] Thalassemia happens when you inherit certain gene mutations or gene deletions. Alpha-thalassemia usually involves mutations in the HBA1 and HBA2 genes, but there are rare syndromes involving other genes. Beta-thalassemia is usually the result of a mutation in the HBB gene. […] Acquired alpha-thalassemia or beta-thalassemia are rare and usually seen when a person has a type of blood cancer. The cancerous cells have undergone non-inherited genetic changes that result in thalassemia.

• #1 Acquired beta-Thalassemia as an Etiology of Microcytic Anemia in Primary Myelofibrosis | Kanasaki | Journal of Hematology

  https://thejh.org/index.php/jh/article/view/190/153

  Acquired thalassemia is reported to be associated with various hematological diseases, especially with myelodysplastic syndromes, and may exacerbate anemia although acquired thalassemia among PMF patients is rarely reported. […] Acquired -thalassemia is caused by either acquired deletion of -globin gene cluster or inactivation mutations of trans-activating chromatin-activating factor; however, acquired -thalassemia is much rarer and its mechanism has not been fully elucidated. […] However, considering the high frequency of microcytosis among PMF patients, we believe that acquired -thalassemia is one of the mechanisms of the microcytosis and the present case exemplifies this contention. […] Although we could not perform genetic studies and make a definitive diagnosis, we believe that -thalassemia in the present case is acquired rather than hereditary which developed with the progression of PMF because his RBCs were originally normocytic and he had no family history of hemoglobinopathy or anemia.

• #1 Thalassemia: Types, Causes, Symptoms & Treatment | Medanta

  https://www.medanta.org/pillar/thalassemia-types-symptoms-causes-diagnosis-treatment

  Thalassemia is a genetic blood disorder characterized by the body’s inability to produce sufficient hemoglobin amount, the protein present in red blood cells responsible for transporting oxygen throughout the body. […] Thalassemia is inherited, meaning it is passed down from parents to their children through genes. […] Understanding thalassemia involves delving into genetics and how our bodies create hemoglobin. This protein is made up of two types of protein chains alpha and beta. Thalassemia occurs when there’s a mutation in the genes that control the production of these protein chains. The severity of thalassemia depends on how many gene mutations a person has inherited, affecting whether they have a mild or severe form of the disease. […] The root cause of thalassemia is genetic mutations that affect the production of hemoglobin. These mutations are inherited, meaning they are passed from parents to their offspring. The specific type of thalassemia you might have depends on the part of the hemoglobin molecule that is affected by the genetic mutations.

• #1 Thalassemia – Symptoms, Types, Causes, Treatment & Prevention | Healthshots

  https://www.healthshots.com/disease/thalassemia/

  Thalassemia is a genetic blood disorder caused by an abnormality or mutation in one of the genes that produce haemoglobin, the protein in red blood cells that carries oxygen throughout the body. This disease is inherited, which means that it is passed down from parents to their children through their genes. If one parent has thalassemia, their child may develop a milder form known as thalassemia minor. If both parents carry thalassemia, the child has a higher risk of inheriting a more severe form, thalassemia major. […] Thalassemia is caused by mutations in the genes that make hemoglobin, the oxygen-carrying protein, in red blood cells. These mutations lead to reduced or abnormal production of haemoglobin, resulting in anaemia. The severity of thalassemia depends on the specific genes affected and their mutation types.

• #1 Thalassaemia: Symptoms and Treatment | Doctor

  https://patient.info/doctor/thalassaemia-pro

  HbH disease results from the deletion or inactivation of three globin genes (oo/ao). It represents a thalassaemia intermedia, with mildly to moderately severe anaemia, splenomegaly, jaundice and abnormal RBC indices. […] In thalassaemia, symptoms of anaemia start when the chain production ceases and the chains fail to form in adequate numbers. […] Iron overload is one of the major causes of morbidity in severe forms of thalassaemia. Iron overload can occur even without transfusions, as absorption is increased and this increases with regular transfusions. […] Endocrine dysfunction secondary to iron overload is common in multiply transfused patients, manifesting as hypogonadotrophic hypogonadism, short stature, acquired hypothyroidism, hypoparathyroidism and diabetes mellitus. […] Gene therapy, particularly targeted at stem cells, is an attractive proposition for the future.

• #2 Thalassemia | Thalassemia | CDC

  https://www.cdc.gov/thalassemia/index.html

  Thalassemia is an inherited (i.e., passed from parents to children through genes) blood disorder caused when the body doesnt make enough of a protein called hemoglobin, an important part of red blood cells. […] Thalassemia is an inherited blood disorder caused when the body doesnt make enough hemoglobin.

• #2 Thalassemia: Symptoms, Causes, & Treatment

  https://www.webmd.com/a-to-z-guides/what-is-thalassemia

  Thalassemia is an inherited blood condition. […] You get thalassemia when you inherit changes (mutations) in certain genes from your parents. These genes control your body’s production of the two proteins that make up hemoglobin, called alpha globin and beta globin. […] Scientists have identified more than 200 gene variations that can cause thalassemia. […] If you get a variant gene from just one parent, you may have mild symptoms or none at all. If you inherit two or more copies of abnormal genes from your parents, you may get mild to severe thalassemia, depending on which type of protein is affected. […] The condition is more common in people with ancestry from Asia, Africa, the Middle East, and Mediterranean countries like Greece or Turkey. […] You can only get thalassemia by inheriting changes or variations in certain genes from your parents. It’s a condition you’re born with, not one you can catch like the flu.

• #2 Beta Thalassemia: Practice Essentials, Etiology, Epidemiology

  https://emedicine.medscape.com/article/206490-overview

  Beta thalassemia is due to mutations in one or both of the beta-globin genes that result in impaired synthesis of the beta-globin protein component of Hb, and subsequently in anemia. […] More than 350 beta-globin gene mutations have been identified in patients with beta thalassemia; this underlies the wide genotypic and phenotypic variability of the disease. […] Beta thalassemia is inherited as an autosomal recessive disorder. […] The defect can be a complete absence of the beta-globin protein (ie, beta-zero thalassemia) or a severely reduced synthesis of the beta-globin protein (ie, beta-plus thalassemia). […] The genetic defect usually is a missense or nonsense mutation in the beta-globin gene. […] In beta thalassemia intermedia the production of beta-globin chains is variably decreased.

• #2 Alpha thalassemia: MedlinePlus GeneticsLock

  https://medlineplus.gov/genetics/condition/alpha-thalassemia/

  Alpha thalassemia typically results from deletions involving the HBA1 and HBA2 genes. Less commonly, changes to the DNA sequence in or near these genes cause alpha thalassemia. Such changes are often referred to as nondeletion variants. Both the HBA1 and HBA2 genes provide instructions for making a protein called alpha-globin, which is a component (subunit) of hemoglobin. […] Hb Bart syndrome, the most severe form of alpha thalassemia, results from the loss or alteration of all four alpha-globin alleles. Such changes prevent the production of any normal alpha-globin. […] HbH disease is usually caused by loss or alteration of three of the four alpha-globin alleles, which sharply reduces the amount of normal alpha-globin produced. Because nondeletion variants are usually more severe than deletions, nondeletion variants in two of the four alpha-globin alleles can result in HbH disease.

• #2 Alpha thalassemia: MedlinePlus GeneticsLock

  https://medlineplus.gov/genetics/condition/alpha-thalassemia/

  With a shortage of alpha-globin, cells make little or no normal hemoglobin. Instead, cells produce abnormal forms of hemoglobin called hemoglobin Bart (Hb Bart) or hemoglobin H (HbH). These abnormal hemoglobin molecules cannot effectively carry oxygen to the body’s tissues. The substitution of Hb Bart or HbH for normal hemoglobin causes anemia and the other serious health problems associated with alpha thalassemia. […] Two additional forms of alpha thalassemia are related to a reduced amount of alpha-globin. Because cells still produce some normal hemoglobin, these forms tend to cause few or no health problems. A loss of two of the four alpha-globin alleles results in alpha thalassemia trait. People with alpha thalassemia trait may have unusually small, pale red blood cells and mild anemia. A loss of one alpha-globin allele is found in alpha thalassemia silent carriers. These individuals typically have no thalassemia-related signs or symptoms. […] Nondeletion variants in one or two alleles cause a range of conditions, from alpha thalassemia silent carrier to HbH disease, depending on the allele involved.

• #2 Beta thalassemia – Wikipedia

  https://en.wikipedia.org/wiki/Beta_thalassemia

  Beta thalassemia occurs due to a mutation of the HBB gene leading to deficient production of the hemoglobin subunit beta-globin; the severity of the disease depends on the nature of the mutation, and whether or not the mutation is homozygous. […] The body’s inability to construct beta-globin leads to reduced or zero production of adult hemoglobin thus causing anemia. […] More than 350 mutations have been identified which can cause beta thalassemia; 20 of these account for 80% of beta-thalassemia cases. […] In beta thalassemia, a single faulty gene can be either asymptomatic or cause mild disease; if both genes are faulty this causes moderate to severe disease.

• #2 Beta Thalassemia (for Parents) | Nemours KidsHealth

  https://kidshealth.org/en/parents/beta-thalassemia.html

  Beta thalassemia is an inherited blood disorder in which the body doesn’t make as much beta globin as it should. […] Someone with beta thalassemia has a change (or mutation) in the beta globin gene that causes less beta globin to be made than typical. The decrease in beta globin causes an imbalance in the amount of alpha and beta globin. This imbalance causes anemia and the other medical problems of beta thalassemia. […] People inherit the instructions (or genes) that make beta globin and alpha globin from their parents. Alpha globins and beta globins join together to make the hemoglobin that is inside of red blood cells. Every child inherits two genes that make beta globin: one from each parent. […] Someone who inherits a beta thalassemia mutation from one parent has beta thalassemia trait (beta thalassemia minor).

• #2 Thalassemias – Hematology and Oncology – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/hematology-and-oncology/anemias-caused-by-hemolysis/thalassemias

  Thalassemias are a group of inherited microcytic, hemolytic anemias characterized by defective hemoglobin synthesis. […] Alpha-thalassemia results from decreased production of alpha-polypeptide chains due to a deletion of one or more alpha genes. […] 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. […] 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 and ineffective erythropoiesis due to damage from the unpaired hemoglobin chains (causing anemia).

• #2 Thalassemia: Pathophysiology, Diagnosis, and Advances in Treatment

  https://www.mdpi.com/2039-4365/14/4/10

  Thalassemia is a group of genetic blood disorders characterized by the reduced synthesis of normal hemoglobin chains, leading to hypochromic microcytic anemias. […] Beta-thalassemia results from mutations in the β-globin gene, causing reduced beta-globin production and an imbalance in globin chains, leading to ineffective erythropoiesis and anemia. […] The pathogenesis involves the accumulation of unmatched globin chains, like alpha-globin in beta-thalassemia, causing hemolysis and ineffective erythropoiesis, possibly due to accelerated apoptosis from alpha-globin deposition in erythroid precursors. […] The clinical impact of thalassemia is significant, with severe cases requiring lifelong transfusion support and iron chelation therapy.

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  https://www.cgh.com.sg/patient-care/conditions-treatments/thalassaemia

  Thalassemia is a genetic condition and is caused by mutation in the genetic material of cells that make haemoglobin which is involved in the transportation of oxygen. This mutation can be passed from parents to their children. […] The main risk factors for thalassaemia include: Family history: If either parent carries the genetic mutations responsible for thalassaemia, there is a higher likelihood of inheriting the condition. This is especially true for both alpha and beta thalassaemia. […] Ethnic background: People of certain ethnicities are at higher risk. Thalassaemia is most common among those of Mediterranean, Middle Eastern, South Asian and African descent due to the higher prevalence of the genes that cause this condition in these populations. […] Carrying the thalassaemia gene: Even if an individual does not show symptoms, they may be a carrier of the thalassaemia trait (thalassaemia minor) and can pass it on to their children.

• #2 Thalassemia: Causes, Symptoms, Diagnosis, and Treatment

  https://www.healthline.com/health/thalassemia

  Thalassemia is inherited, meaning that at least one of your parents must be a carrier of the disorder. Its caused by either a genetic mutation or a deletion of certain key gene fragments. […] Thalassemia occurs when theres an abnormality or mutation in one of the genes involved in hemoglobin production. You inherit this genetic abnormality from your parents. […] Thalassemia is most common in people from Asia, the Middle East, Africa, and Mediterranean countries such as Greece and Turkey. […] Thalassemia is genetic in nature. To develop full thalassemia, both of your parents must be carriers of the disease. As a result, you will have two mutated genes. […] Its also possible to become a carrier of thalassemia, where you only have one mutated gene and not two from both parents. Either one or both of your parents must have the condition or be a carrier of it. This means that you inherit one mutated gene from either one of your parents.

• #2 Thalassemia | Radiology Reference Article | Radiopaedia.org

  https://radiopaedia.org/articles/thalassaemia-1?lang=us

  Thalassemia is an autosomal recessive hemoglobinopathy first described in the Mediterranean region. The genetic defect causes a reduction in the rate of globin chain synthesis which causes the formation of abnormal hemoglobin molecules. The resultant microcytic anemia is the characteristic presenting symptom of thalassemias. […] The thalassemias are classified according to the affected chain of the hemoglobin molecule. In thalassemias, production of the globin chain is reduced, while in thalassemia production of the globin chain is reduced. […] Deletion of one of the loci has a high prevalence in people of African or Asian descent, making them more likely to develop thalassemias. thalassemias are common in Africans, but also in Greeks and Italians. […] The thalassemia trait may confer a degree of protection against malaria, which confers a selective survival advantage on carriers.

• #2 Thalassaemia: Causes and Types

  https://patient.info/allergies-blood-immune/thalassaemia-leaflet

  Worldwide, thalassaemia is one of the most common inherited diseases. […] The World Health Organization (WHO) estimates that about 3 people in every 200 of the world’s population may be beta thalassaemia carriers and that at least 60,000 severely affected people are born each year. […] A child inherits haemoglobin genes from both parents. […] Thalassaemia is most common in people whose family origins are Mediterranean or Asian. […] The diagnosis is made by a blood test. […] In some cases, extra tests such as DNA (genetic) tests are needed to diagnose the exact type of thalassaemia. […] The advantage of having tests before you become pregnant, is that you will know whether or not there is a possibility that your baby could inherit a severe form of thalassaemia. […] Blood transfusions are started if you (or your child) have anaemia plus other symptoms, such as poor growth, not feeding well or other problems.

• #2 Thalassemia | Lurie Children’s

  https://www.luriechildrens.org/en/specialties-conditions/thalassemia/

  Silent carrier A person who is a silent carrier has a 50 percent chance of passing on this gene change to any children they may have. […] Hemoglobin constant spring A person with hemoglobin constant spring has a 50 percent chance of passing on this gene change to any children they may have and needs to be aware of any abnormal hemoglobin their partner may carry that could also be passed on to their children. […] Alpha thalassemia trait A person with alpha thalassemia trait has a 50 percent chance of passing on one or both deletions to any children they may have and needs to be aware of any abnormal hemoglobin their partner may carry that could also be passed on to their children. […] Hemoglobin H disease A person with hemoglobin H disease will pass on one or two alpha globin gene deletions to any children they may have and needs to be aware of any abnormal hemoglobin their partner may carry that could also be passed on to their children.

• #2 Thalassaemia | Better Health Channel

  https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/thalassaemia

  Thalassaemia is the most common inherited blood condition in the world. This condition is caused by changes to the genes for haemoglobin. […] Changes affecting haemoglobin result in severe anaemia. […] There are two different types of thalassaemia: alpha (a) and beta (b). Alpha-thalassaemia involves genetic changes in two genes (HBA1 and HBA2). Beta-thalassaemia involves changes in one gene (HBB). […] If two people who are carriers of the same type of thalassaemia have children, their children have a: 25 per cent risk of developing thalassaemia major because they inherited the thalassaemia gene from both parents. […] Thalassaemia can be diagnosed through blood tests and genetic testing. […] It is suggested that all couples thought to be at risk be tested for thalassaemia carrier status, especially before starting a family. […] Genetic counsellors are health professionals qualified in both counselling and genetics. […] They can help you to understand thalassaemia and what causes it, how it is inherited, and what a diagnosis means for your child’s health and development.

• #2 Thalassemia Trait (Minor): How Does It Affect You?

  https://www.healthline.com/health/thalassemia-trait

  Alpha-thalassemia occurs when your body has trouble producing hemoglobin alpha. Beta-thalassemia occurs when your body has trouble producing hemoglobin beta. […] If the inherited mutation affects only one gene, you have beta-thalassemia minor. Like in alpha-thalassemia minor, your red blood cells will be smaller, and you may experience mild anemia. […] If you have beta-thalassemia trait, you have a 50% chance of passing on the affected gene to any child you have. […] If both parents carry a trait for either alpha- or beta-thalassemia, their child could develop a severe form of the disease. […] If you have thalassemia trait, it means you carry a genetic mutation that causes thalassemia, but you dont have the disease yourself. You likely wont have any symptoms. If you do, theyll be mild. […] But you can pass the gene on to future generations.

• #2 Alpha and Beta Thalassemia | AAFP

  https://www.aafp.org/pubs/afp/issues/2009/0815/p339.html

  The thalassemias are a group of inherited hematologic disorders caused by defects in the synthesis of one or more of the hemoglobin chains. Alpha thalassemia is caused by reduced or absent synthesis of alpha globin chains, and beta thalassemia is caused by reduced or absent synthesis of beta globin chains. […] Beta thalassemia is the result of deficient or absent synthesis of beta globin chains, leading to excess alpha chains. Beta globin synthesis is controlled by one gene on each chromosome 11. Beta thalassemia occurs from any of more than 200 point mutations and (rarely) deletions of the two genes. […] A thalassemia results in an abnormally low quantity of a globin chain. Rarely, persons will have coexisting hemoglobinopathy and thalassemia.

• #2 Beta Thalassemia | Northern California Comprehensive Thalassemia Center

  https://thalassemia.ucsf.edu/thalassemia-information/what-is-thalassemia/beta-thalassemia

  There are hundreds of mutations within the beta globin gene, but approximately 20 different alleles comprise 80% of the mutations found world wide. […] The beta thalassemia syndromes are much more diverse than the alpha thalassemia syndromes due to the diversity of the mutations that produce the defects in the beta globin gene. […] Beta thalassemias are caused by mutations on chromosome 11 that affect all aspects of beta globin production: transcription, translation, and the stability of the beta globin product. […] Splice site mutations also occur and are of clinical consequence, when combined with a thalassemia mutation. […] Hemoglobin E is a very common abnormal hemoglobin in the Southeast Asian population, and when paired with a b0 thalassemia mutation, can produce severe transfusion-dependent (Eb0) thalassemia.

• #2 Acquired beta-Thalassemia as an Etiology of Microcytic Anemia in Primary Myelofibrosis | Kanasaki | Journal of Hematology

  https://thejh.org/index.php/jh/article/view/190/153

  Acquired thalassemia is reported to be associated with various hematological diseases, especially with myelodysplastic syndromes, and may exacerbate anemia although acquired thalassemia among PMF patients is rarely reported. […] Acquired -thalassemia is caused by either acquired deletion of -globin gene cluster or inactivation mutations of trans-activating chromatin-activating factor; however, acquired -thalassemia is much rarer and its mechanism has not been fully elucidated. […] However, considering the high frequency of microcytosis among PMF patients, we believe that acquired -thalassemia is one of the mechanisms of the microcytosis and the present case exemplifies this contention. […] Although we could not perform genetic studies and make a definitive diagnosis, we believe that -thalassemia in the present case is acquired rather than hereditary which developed with the progression of PMF because his RBCs were originally normocytic and he had no family history of hemoglobinopathy or anemia.

• #2 Thalassemia: Pathophysiology, Diagnosis, and Advances in Treatment

  https://www.mdpi.com/2039-4365/14/4/10

  Thalassemia represents a diverse group of inherited hematological disorders characterized by defective globin chain synthesis, leading to chronic anemia and associated complications. The complicated pathophysiology of beta-thalassemia involves genetic mutations or rarely deletions of the beta-globin gene on chromosome 11 whereas alpha-thalassemia involves deletions in the HBA1 and HBA2 genes or occasionally alterations to the DNA sequence in or around these genes. […] The genetic basis of thalassemia involves mutations that affect the expression of globin genes, particularly the β-globin gene, resulting in reduced or absent synthesis of β-globin chains. […] The pathophysiology of thalassemia involves a disruption in the balance of globin chain synthesis, leading to an imbalance in the alpha- and beta-globin chains and subsequent abnormalities in red blood cell formation and function.

• #2 Thalassaemia | healthdirect

  https://www.healthdirect.gov.au/thalassaemia

  Thalassaemia is an inherited genetic disorder that affects the blood and causes lifelong anaemia. […] Thalassaemia is caused by inheriting a gene mutation (change in the normal DNA) from one or both parents. The gene mutation makes the body lose red blood cells more quickly than normal, resulting in less healthy haemoglobin to carry oxygen around the body. […] There are different types of thalassaemia. The type someone has depends on which gene mutation they inherit.

• #2 Thalassemia – Symptoms, Types, Causes, Treatment & Prevention | Healthshots

  https://www.healthshots.com/disease/thalassemia/

  The primary issue in thalassemia is the body’s inability to produce normal amounts of haemoglobin, the protein in red blood cells that carries oxygen. This results in anaemia and reduced oxygen delivery to the body’s tissues, increasing the need for treatments such as blood transfusions and iron chelation to manage symptoms and prevent complications. […] The only established cure for thalassemia is a bone marrow or stem cell transplant, which can be highly effective, especially in younger patients with a matched donor. However, this procedure carries significant risks and is not suitable for all patients.

• #3 Thalassemia – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK545151/

  Thalassemia is autosomal recessive, which means both the parents must be affected with or carriers for the disease to transfer it to the next generation. It is caused by mutations or deletions of the Hb genes, resulting in underproduction or absence of alpha or beta chains. There are over 200 mutations identified as the culprits for causing thalassemias. Alpha thalassemia is caused by deletions of alpha-globin genes, and beta thalassemias are caused by a point mutation in splice site and promoter regions of the beta-globin gene on chromosome 11. […] Thalassemias are a heterogeneous grouping of genetic disorders that result from a decreased synthesis of alpha or beta chains of hemoglobin (Hb). Hemoglobin serves as the oxygen-carrying component of the red blood cells. It consists of two proteins, an alpha, and a beta. If the body does not manufacture enough of one or the other of these two proteins, the red blood cells do not form correctly and cannot carry sufficient oxygen; this causes anemia that begins in early childhood and lasts throughout life. Thalassemia is an inherited disease, meaning that at least one of the parents must be a carrier for the disease. It is caused by either a genetic mutation or a deletion of certain key gene fragments.

• #3 Thalassemia: Types, Causes, Symptoms & Treatment | Medanta

  https://www.medanta.org/pillar/thalassemia-types-symptoms-causes-diagnosis-treatment

  Thalassemia is inherited in an autosomal recessive pattern, meaning that for a child to have thalassemia, both parents must carry and pass on the mutated gene. If only one parent passes on the gene, the child will be a carrier and may not show disease symptoms. […] The primary risk factor for thalassemia is having a family history of the disease. If both parents are carriers of the thalassemia gene, their children have a 25% chance of having the disease. Ethnic background also plays a significant role, with individuals from Mediterranean, South Asian, Southeast Asian, and Middle Eastern ancestries at higher risk. […] Thalassemia major is a preventable disease. Genetic counselling and prenatal testing can help at-risk couples assess their likelihood of having a child with the condition.

• #3 Thalassemia: Causes, Symptoms, Diagnosis – SelfDecode Health

  https://health.selfdecode.com/blog/thalassemia/

  Thalassemias are genetic disorders caused by over 300 known mutations in the hemoglobin genes. […] Thalassemias are caused by changes or deletions in the hemoglobin genes. Everyone inherits 2 copies of each gene, one from each parent. […] Severe forms of thalassemia occur when a person inherits multiple defective copies. Men and women are at equal risk of inheriting it, meaning the genes that affect thalassemia are on non-sex chromosomes (autosomal disease). […] The following genes affect hemoglobin subunits: Alpha HBA1 and HBA2, found on chromosome 16; Beta HBB, found on chromosome 11; Delta HBD, found on chromosome 11; Gamma HBG1 and HBG2, found on chromosome 11. […] Defective or reduced production of the alpha subunits results in alpha-thalassemia. […] Reduced production of the beta subunit and thus reduced adult hemoglobin levels in the blood can cause beta-thalassemia.

• #3 Alpha Thalassemia Treatment | St. Jude Care & Treatment

  https://www.stjude.org/care-treatment/treatment/blood-disorders/alpha-thalassemia.html

  Alpha thalassemia is caused when the genes that control how the body makes hemoglobin change or are missing. The hemoglobin protein that is affected in alpha thalassemia is alpha globin. […] Carriers are people who inherit hemoglobin genes that are changed or missing from 1 parent but inherit normal genes from the other parent. Carriers of alpha thalassemia usually do not have symptoms. But they can pass the affected genes on to their children. People who have moderate-to-severe forms of alpha thalassemia inherited affected hemoglobin genes from both parents. […] Alpha globin is made by 4 copies of the alpha globin gene 2 copies are on each strand of chromosome 16. Each person needs these 4 genes (2 from each parent) to make enough alpha globin for the body to make healthy hemoglobin. Different forms of alpha thalassemia occur if 1 or more of these genes are missing:

• #3 Alpha Thalassemia (for Parents) | Nemours KidsHealth

  https://kidshealth.org/en/parents/thalassemias.html

  Alpha thalassemia is caused by a mutation (or change) in the gene (or instructions) that controls how much alpha globin to make. Hemoglobin is made of two alpha globins and two beta globins. In alpha thalassemia, the body makes less alpha globin than beta globin because of the gene mutation. The imbalance in alpha and beta globin causes anemia and leads to the other medical problems from alpha thalassemia. […] Someone with alpha thalassemia has a change (or mutation) in the alpha globin gene that causes less alpha globin to be made than typical. The decrease in alpha globin causes an imbalance in the amount of alpha and beta globin. This imbalance causes anemia and the other medical problems of alpha thalassemia.

• #3 Beta Thalassemia: Types, Symptoms & Treatment

  https://my.clevelandclinic.org/health/diseases/23574-beta-thalassemia

  Beta thalassemia results from a mutation (error) that limits beta-globin production in your body. […] Mutations of the alpha-globin chain cause alpha thalassemia, while mutations of the beta-globin chain cause beta thalassemia. […] You inherit the gene mutation for beta thalassemia in an autosomal recessive pattern. […] In rare instances, inheriting just one mutated beta-globin gene causes beta thalassemia. […] The number of defective genes you inherit and the mutations location will determine your conditions severity. […] Some mutations cause no beta-globin to be produced (beta-zero thalassemia). […] Other mutations cause too little beta-globin to be made (beta-plus thalassemia). […] Beta thalassemia major (Cooleys anemia) is the most severe kind of beta thalassemia. […] Beta thalassemia intermedia may cause mild to moderate anemia symptoms. […] Beta thalassemia minor (beta thalassemia trait) often causes mild anemia symptoms.

• #3 Thalassaemia: Causes and Types

  https://patient.info/allergies-blood-immune/thalassaemia-leaflet

  Thalassaemia is an inherited (genetic) condition affecting the blood. […] The cause is an inherited (genetic) change, involving the genes which tell the body how to make an important chemical called haemoglobin. […] In thalassaemia, part of the haemoglobin is faulty – usually either the alpha chains or the beta chains. […] Depending on the type of thalassaemia, the amount of abnormal haemoglobin varies. […] The main types of thalassaemia are called alpha thalassaemia and beta thalassaemia. […] Each type of thalassaemia (alpha and beta) is then classified into more types, according to how severe the condition is. […] The more severe beta types are beta thalassaemia major (BTM) and beta thalassaemia intermedia (BTI). […] This is a type of alpha thalassaemia. […] This is the most severe form of thalassaemia, where all the alpha-haemoglobin genes are abnormal or missing.

• #3 Thalassaemia: Symptoms and Treatment | Doctor

  https://patient.info/doctor/thalassaemia-pro

  HbH disease results from the deletion or inactivation of three globin genes (oo/ao). It represents a thalassaemia intermedia, with mildly to moderately severe anaemia, splenomegaly, jaundice and abnormal RBC indices. […] In thalassaemia, symptoms of anaemia start when the chain production ceases and the chains fail to form in adequate numbers. […] Iron overload is one of the major causes of morbidity in severe forms of thalassaemia. Iron overload can occur even without transfusions, as absorption is increased and this increases with regular transfusions. […] Endocrine dysfunction secondary to iron overload is common in multiply transfused patients, manifesting as hypogonadotrophic hypogonadism, short stature, acquired hypothyroidism, hypoparathyroidism and diabetes mellitus. […] Gene therapy, particularly targeted at stem cells, is an attractive proposition for the future.

• #3 Limitations of Whole Genome Sequencing in Genetic Testing

  https://3billion.io/blog/rare-disease-series-3-thalassemia

  Two Alpha thalassemia related genes, HBA1 and HBA2 are located on chromosome 16 and one Beta thalassemia related gene, HBB is located on chromosome 11. […] Thalassemia is a rare genetic disease that reduces the production of hemoglobin, leading to anemia. […] Alpha thalassemia is a disorder in which the body cannot produce the alpha subunit of hemoglobin. Likewise, beta thalassemia involves difficulty producing the beta subunit. As such, thalassemia affects the production of normal hemoglobin. […] The inheritance pattern of alpha thalassemia is complex. The severity depends on the number of mutated genes. […] Beta thalassemia is usually inherited in an autosomal recessive pattern. […] Thalassemia diagnosis is mostly based on a blood test. […] There are multiple types of thalassemia and different types of treatment.

• #3 Beta Thalassemia (for Parents) | Nemours KidsHealth

  https://kidshealth.org/en/parents/beta-thalassemia.html

  Someone who inherits a beta thalassemia mutation from each parent has beta thalassemia intermedia or beta thalassemia major (Cooley’s anemia). […] Sometimes a child inherits a beta thalassemia mutation from one parent and a sickle cell mutation from the other parent. This results in a type of sickle cell disease called sickle-beta thalassemia.

• #3 Thalassemia | Dana-Farber Cancer Institute

  https://www.dana-farber.org/cancer-care/types/thalassemia

  Thalassemia is caused by defective genes that affect hemoglobin production. These mutated genes are passed from parents to their biological children. […] Thalassemia is a genetic condition passed down from one or both biological parents with a genetic mutation. It is common in those of Southeast Asian, African, and Mediterranean descent.

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