Also known as Cooley’s anemia, this genetic blood disorder is part of a group of hematologic disorders known as thalassemia. There are multiple categories of thalassemia, and they are one of many subtypes of a common condition known as anemia.
This type of anemia can seem complicated because of the multiple variations in inheritance and expression of abnormal genes. This abnormality results in the excessive destruction of red blood cells. Red blood cells carry hemoglobin, and it is a mix of alpha globin and beta globin proteins.
It is the beta globin protein that is affected in this type of thalassemia. This results in a decreased production of the beta globin protein in hemoglobin. This protein deficiency results in a decrease in the total amount of hemoglobin measured in the blood stream. Deficiencies of hemoglobin, also known as anemia, decrease the availability of red blood cells to transport oxygen from the lungs to the rest of the body.
Where Does It Come From?
The genetic factors identified in this type of anemia are traced to the Mediterranean and surrounding regions. In fact the term thalassemia is derived from Greek roots meaning ‘sea’ and ‘blood’. It is interesting to note that some studies suggest the thalassemia trait may actually afford some immunologic protection against malaria, and areas that have been associated with a higher prevalence of malaria occur in the same areas associated with a greater prevalence of this genetic trait.
Beta-thalassemia is actually a group of genetic disorders with many subtypes and expressions resulting in a range of severity and symptomatology. This genetic abnormality is classified most commonly through three primary groups. These groups include thalassemia major, thalassemia intermedia, and thalassemia minor. The distinction among them is defined by the variability of the inheritance of genes from one parent or both parents. Expression of the defective gene.
Those individuals who receive only one defective gene from one parent are in the thalassemia minor group while those who receive a defective gene from both parents are diagnosed as having thalassemia major.
What Symptoms Occur?
Thalassemia minor is typically asymptomatic. It is detected and diagnosed by examining the abnormal hemoglobin protein through electrophoresis or mutational analysis. It is an important diagnosis to make for genetic counseling and prenatal risk assessment.
Individuals with this type of thalassemia should be closely followed by their doctors as complications can occur including enlargement of the spleen and liver abnormalities. Recent studies have also suggested there may be an increased risk of infection and mood disorders associated with thalassemia minor.
Beta-thalassemia major is the severe form that occurs from acquiring the abnormal gene from both parents. These individuals develop severe anemia which require intensive treatment and medical care. Though often normal at birth, severe symptoms develop and can result in heart failure and liver abnormalities resulting in early death.
How Is It Treated?
Patients with severe symptoms are often treated with blood transfusions and require other procedures such as chelation therapy to remove the increased iron that occurs along with the transfusions. Bone marrow transplants may be performed especially in children to treat this severe form of anemia.