Is thalassemia a dominant or recessive?
These mildly affected people are said to have thalassemia minor. In a small percentage of families, the HBB gene mutation is inherited in an autosomal dominant manner. In these cases, one copy of the altered gene in each cell is sufficient to cause the signs and symptoms of beta thalassemia.
Both types of thalassemia are inherited in the same manner. The disease is passed to children by parents who carry the mutated thalassemia gene. A child who inherits one mutated gene is a carrier, which is sometimes called "thalassemia trait." Most carriers lead completely normal, healthy lives.
- Beta thalassemias (β thalassemias) are a group of inherited blood disorders. They are forms of thalassemia caused by reduced or absent synthesis of the beta chains of hemoglobin that result in variable outcomes ranging from severe anemia to clinically asymptomatic individuals.
- The Man Behind the Name: Thomas Benton Cooley, M.D. People often ask why the major form of thalassemia is known as Cooley's anemia. Thalassemia major is widely referred to as Cooley's anemia in reference to Dr. Thomas Benton Cooley, the renowned researcher who discovered the disorder.
- When someone has beta thalassemia, there is a mutation in chromosome 11. Beta globin is made on chromosome 11 (beta globin, along with alpha globin, is one of the proteins that makes up hemoglobin). So, if one or both of the genes that tells chromosome 11 to produce beta globin is altered, less beta globin is made.
When someone has beta thalassemia, there is a mutation in chromosome 11. Beta globin is made on chromosome 11 (beta globin, along with alpha globin, is one of the proteins that makes up hemoglobin). So, if one or both of the genes that tells chromosome 11 to produce beta globin is altered, less beta globin is made.
- Thalassemia is caused by mutations in the DNA of cells that make hemoglobin — the substance in your red blood cells that carries oxygen throughout your body. The mutations associated with thalassemia are passed from parents to children.
- Delta Beta-thalassaemia: is a disorder of haemoglobin, a major component of the red blood cells. Haemoglobin is produced at a reduced rate. One can be a carrier and in this case it is a benign disease close the Β-thalassemia –trait or carrier and should be distinguished from an iron deficiency.
- The person is said to be heterozygous for beta thalassemia. Persons with thalassemia minor have (at most) mild anemia (slight lowering of the hemoglobin level in the blood). This situation can very closely resemble that with mild iron-deficiency anemia. Hence, the name Cooley's anemia in his honor.
The inheritance of alpha-thalassemia is complex because the condition involves two genes : HBA1 and HBA2. If both parents are missing at least one alpha-globin allele, each of their children are at risk of having Hb Bart syndrome or hydrops fetalis, hemoglobin H (HbH) disease, or alpha-thalassemia trait .
- Individuals with mild forms of alpha thalassemia may not require specific treatment except as needed for management of low hemoglobin levels. In some patients, supplementation of iron or folic acid may be useful. Patients with more severe anemia may require lifelong transfusion therapy.
- There are four types of alpha thalassemia, hemoglobin Bart hydrops fetalis syndrome or Hb Bart syndrome (the more severe form), HbH disease, silent carrier state and trait. However, many people with this type of thalassemia have no signs or symptoms.
- The picture shows one example of how beta thalassemia is inherited. The beta globin gene is located on chromosome 11. A child inherits two beta globin genes (one from each parent). In this example, each parent has one altered beta globin gene.
Updated: 2nd October 2019