Question: What is (are) Thalassemia ?
Answer: Thalassemia is an inherited blood disorder that reduces the production of functional hemoglobin (the protein in red blood cells that carries oxygen). This causes a shortage of red blood cells and low levels of oxygen in the bloodstream, leading to a variety of health problems. There are two main types of thalassemia, alpha thalassemia and beta thalassemia. Signs and symptoms vary but may include mild to severe anemia, paleness, fatigue, yellow discoloration of skin (jaundice), and bone problems. Beta thalassemia is caused by changes (mutations) in the HBB gene while alpha thalassemia is caused by mutations in the HBA1 and/or HBA2 genes. Both are inherited in an autosomal recessive manner. Treatment depends on the type and severity of the condition but may include blood transfusions and/or folic acid supplements.
Source: GARD

Question: What are the symptoms of Thalassemia ?
Answer: What are the signs and symptoms of Thalassemia? The signs and symptoms vary depending on the severity of the thalassemia. For example, people affected by milder forms of thalassemia can develop mild anemia or may have no signs or symptoms of the condition at all. Intermediate forms of thalassemia can cause mild to moderate anemia and may be associated with other health problems such as slowed growth, delayed puberty, bone problems and/or an enlarged spleen. In addition to the signs and symptoms seen in intermediate thalassemia, people with severe forms of thalassemia may also experience severe anemia, poor appetite, paleness, dark urine, yellow discoloration of skin (jaundice), and enlarged liver or heart. For more information on the signs and symptoms by type of thalassemia, please click here. The Human Phenotype Ontology provides the following list of signs and symptoms for Thalassemia. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms. Signs and Symptoms Approximate number of patients (when available) Abnormality of the heme biosynthetic pathway 90% Abnormality of immune system physiology 7.5% Biliary tract abnormality 7.5% Cognitive impairment 7.5% Hemolytic anemia 7.5% Hydrops fetalis 7.5% Hypersplenism 7.5% Myelodysplasia 7.5% Splenomegaly 7.5% Hypochromic microcytic anemia - Reduced alpha/beta synthesis ratio - The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature. The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined. Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
Source: GARD

Question: What causes Thalassemia ?
Answer: What causes thalassemia? There are two main types of thalassemia, alpha thalassemia and beta thalassemia, which each affect a different part of hemoglobin (the protein in red blood cells that carries oxygen). Hemoglobin is made up of two different components (subunits): beta globin and alpha globin. The HBB gene provides instructions for making beta globin, while the HBA1 and HBA2 genes provide instructions for making alpha globin. Each person has two copies of each of these genes, one inherited from the mother and one from the father. Changes (mutations) in the HBB gene lead to reduced levels of beta globin and cause beta thalassemia. Loss (deletion) of some or all of the HBA1 and/or HBA2 genes results in a shortage of alpha globin, leading to alpha thalassemia.
Source: GARD

Question: Is Thalassemia inherited ?
Answer: How is thalassemia inherited? In general, thalassemia is inherited in an autosomal recessive manner; however, the inheritance can be quite complex as multiple genes can influence the production of hemoglobin. Most people affected by beta thalassemia have mutations in both copies of the HBB gene in each cell. The parents of an affected person usually each carry one mutated copy of the gene and are referred to as carriers. Carriers typically do not show signs or symptoms of the condition; although some carriers of beta thalassemia develop mild anemia. When two carriers of an autosomal recessive condition have children, each child has a 25% (1 in 4) risk to have the condition, a 50% (1 in 2) risk to be a carrier like each of the parents, and a 25% chance to not have the condition and not be a carrier. The inheritance of alpha thalassemia is complicated by the fact that mutations in two different genes (HBA1 and HBA2) are associated with the condition. People have two copies of the HBA1 gene and two copies of the HBA2 gene in each cell. For each gene, one copy is inherited from the mother and one is inherited from the father. If each parent is missing at least one gene copy, their children are at risk for having alpha thalassemia. However, the exact risk and the severity of each child's condition depends on how many gene copies are lost (deleted) and which combination of the HBA1 and HBA2 genes are affected.
Source: GARD

Question: How to diagnose Thalassemia ?
Answer: Is genetic testing available for thalassemia? Yes, genetic testing is available for HBB, HBA1 and HBA2, the genes known to cause thalassemia. Carrier testing for at-risk relatives and prenatal testing are possible if the disease-causing mutations in the family are known. The Genetic Testing Registry (GTR) is a centralized online resource for information about genetic tests. It has additional information on genetic testing for alpha thalassemia and beta thalassemia. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
Source: GARD