If both parents carry a hemoglobinopathy trait, the risk is 25% for each pregnancy for an affected child. PhD FACMG), Northern California Comprehensive Thalassemia Center, 747 52nd Street, Oakland CA 94609 •
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This is called alpha thalassemia major or hydrops fetalis, and babies with this condition usually die before or shortly after birth. Hemoglobin is a protein found in red blood cells that carries oxygen throughout the body. When beta-globin is produced in reduced amounts, this is known as beta-plus thalassemia or B+ thalassemia. Testing can also be completed during the 16th week of pregnancy through amniocentesis. It is also a single gene disorderwhere the mutation will only affect the expression of one specific gene as compared to a complex cluster of genes. These people are generally identified on routine complete blood count(CBC). Hemoglobin is a protein in red blood cells that carries oxygen and nutrients to cells in the body. For the autosomal recessive forms of the disease, both parents must be carriers for a child to be affected. Although most of the time thalassemia major will be identified on the newborn screen, people with thalassemia intermedia may not be identified until years later. The highest incidences of thalassemia are reported in Cyprus, Sardinia, and Southeast Asia. Blood transfusions allow young people to enjoy normal activities and live into adulthood. Thalassemias occur most often among people of Mediterranean, Italian, Greek, Transcaucasus, Middle Eastern, Southern Asian, African and African-American descent. The HBB gene provides instructions for making protein chains called beta-globin, a subunit of hemoglobin. This will determine whether to move forward with a family or to have a fetus tested for thalassemia. Both thalassemia major and thalassemia intermedia can cause more than just anemia. A list of references is also included at the bottom of this article. These tests are not typically medically verified and should not be used to make medical decisions. When no beta-globin is produced, this is known as beta-zero thalassemia or B0 thalassemia. Iron chelation treatment can be time consuming and somewhat painful. This condition is called beta thalassemia trait or beta thalassemia minor and causes mild anemia. In a few cases, there may be reaction to the transfusion that could affect the lungs and heart or produce a fever. ... A diagram … Thalassemiais inherited in an autosomal recessive pattern which means the mutated genes that will cause this blood disorder is located on the autosomal chromosomes (11 and 16). People with alpha or beta thalassemia trait may have mild anemia. The HFE gene mutates in patients suffering from the common iron overload disease hemochromatosis. Complications from iron overload include: Heart disease due to iron overload is the leading cause of death in people who have thalassemias. 16 for a total of four. These can also be used to determine if someone is just a carrier. There are several kinds of beta thalassemia: Genes are the instructions for a body to grow and function. In the diagram below (known as a punnett square), these genes are represented by the letters A and S. ... gene. This can be confused with iron deficiency anemia. Silent carriers of alpha thalassemia show no signs or symptoms of the condition. The thalassemias are a group of recessively inherited conditions. Recall that hemoglobin is the protein that is affected in thalassemia. The information on this website is not to be used as a substitute for medical advice, diagnosis, and/or treatment. Folic acid is a B vitamin that helps to build healthy red blood cells. Not following a regimen can lead to fatal complications. Not all children who inherit a mutated gene from one parent with thalassemia will develop the condition. Explain the molecular genetics and inheritance of alpha and beta thalassemias. Side effects include problems with vision and hearing. It is sometimes misdiagnosed as iron-deficiency anemia. The instructions for beta globin production are on chromosome 11,
It is important to know that your genes are not your destiny. If you suffer from fear, depression or stress related to this condition, consider getting psychological help. It is passed on the children by parents who carry a mutated thalassemia gene. However, that quality of life does depend on following a strict treatment regimen. They may be prone to severe anemia and many other health problems, including: For example, with beta thalassemia major in some developing countries, treatments that include long-term transfusion programs are not available. Recall that genes come in pairs. (images courtesy of Phil Cotter,
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