Blood tests are required for a thalassaemia diagnosis. Thalassaemia itself is an inherited blood disorder in which an individual has fewer red blood cells and less hemoglobin than he normally should. Blood tests assess different aspects of red blood cells, such as appearance and cell count. In addition, blood tests also evaluate hemoglobin, the protein inside red blood cells that carries oxygen throughout the body. For prenatal thalassaemia diagnosis, tests include amniocentesis or chorionic villus sampling (CVS).
In an individual with thalassaemia, physical characteristics of red blood cells include being abnormally-shaped, pale in color, or unusually small in size. In addition, the affected individual will have a fewer number of red blood cells altogether. As for hemoglobin, the protein will also be lower in abundance, or abnormal. Hemoglobin usually has four protein chains. An individual with thalassaemia will show abnormalities with the alpha or beta protein chains.
During thalassaemia diagnosis, blood tests can also determine if an individual has anemia as a result of the blood disorder. Though anemia is a medical condition that can be caused by a presence of fewer red blood cells or less hemoglobin than normal, it can also occur as a result of low iron. Either there is a problem with a protein chain within the hemoglobin, or the individual lacks enough iron to make adequate hemoglobin for the body. Blood tests will enable the doctor to distinguish the actual cause of anemia, if present.
If warranted, prenatal thalassaemia diagnosis is a procedure to determine if an unborn baby has the blood disorder, and how severe it might be. Amniocentesis and CVS are two tests used to determine this. Both procedures involve taking a sample for evaluation. In amniocentesis, the amniotic fluid surrounding the fetus is the sample; for CVS, the sample is a piece of the placenta.
Since thalassaemia is an inherited disorder, it is understandable to undergo prenatal testing if both parents are carriers. This is because a severe form of the illness can cause stillbirth. Otherwise, diagnosis usually follows an onset of symptoms that point towards the illness. Generally, symptoms, if any, show up by the time the affected individual is 2-years-old.
Symptoms of thalassaemia include abdominal swelling, facial bone deformities and fatigue. Jaundice, shortness of breath and slowed growth are other symptoms of the blood disorder. Since there are several different types of thalassaemia, symptoms will vary with the type that an individual has; in addition, severity will affect symptoms as well.