Thalassemia minor is an inherited disorder that is caused by a genetic defect. The hemoglobin, which is an iron-rich protein in the red blood cells, consists of two protein chains called the alpha and beta globins. When the genes that control the making of the protein chains in the hemoglobin are missing or altered, then thalassemia occurs.
There are four genes required in the making of the alpha protein chains, two from each parent. If only one gene is missing, then the person is a silent carrier, which means there are no signs of illness but there is a risk for the next generation. If there are two genes missing, then alpha thalassemia minor, also known as alpha thalassemia trait, is the result.
There is a mild anemia associated with this condition. When the genetic mutation involves three genes, the probable result is hemoglobin H disease, for which a moderate to severe anemia is the symptom. In cases where all four genes are missing, the condition is alpha thalassemia major. This usually results in death shortly after birth.
Only two genes are required in the making of the beta protein chain, one from each parent. Beta thalassemia minor is the result of having one altered gene. Again, this causes mild anemia. When both genes are affected, beta thalassemia intermedia or major cause moderate and severe anemia, respectively.
Different races are more prone to one of the blood diseases than the other. Southeast Asian, Chinese, Filipino and Indian peoples are more affected by alpha thalassemia while the beta type is more often found in people of Mediterranean and African descent. The symptom of both types of thalassemia minor is mild anemia but in many cases, there are no signs or symptoms of the condition. Some sufferers may find they are easily fatigued but may not attribute this to a specific cause.
While moderate and severe thalassemias are quite often diagnosed by the time the child is two due to the severity of the symptoms, thalassemia minor is usually diagnosed after anemia is found after a standard blood test. Many times there is confusion as to whether the anemia is because of a deficiency of iron or problems with the making of the globin protein chains. This is resolved by a test measuring the amount of iron in the blood. Sufferers of thalassemia minor usually need little or no treatment.