Home Contacts Search Sitemap  
Logo Title
IntroductionManagementFuture PlansServicesPicture GalleryProjectsEvents
Tests for Thalassaemia

What tests are there for carriers?

A Simple blood test is the most effective test. Unlike many other genetic disorders such as Cystic Fibrosis and Haemophilia, which require complex and often expensive DNA marker testing, (Beta)Thalassaemia carriers are the easiest gene disorder carriers to discover as their red blood will be microcytic (smaller in size) and hypochromic (paler in colour). The test is called Haemoglobin Electrophoresis. 

Tests during a pregnancy the final informed choice:

  • The opportunity to test the foetus is first offered to a couple when BOTH partners have been found to be  Carriers and they then CHOOSE to test the foetus and exercise an informed choice. 
  • There are 3 tests available and they must be done at their respective optimum time. These tests are different from the blood test used to determine a Carrier. Chorionic Villus Sampling (CVS) Test is done at 10 weeks of pregnancy. Fetal blood sampling is done between  18 - 20  weeks and the rarely done Amniocentesis is between 14 - 18 weeks.

How do the tests determine if the foetus is affected?

The choice of which test to use is a very carefully considered matter. However, if the mother has presented herself early in a pregnancy, Chorionic Villus Sampling is the best test because of the ease of doing it and its acceptability to the mother as it can be done earlier in the pregnancy.

  • Chorionic Villus Sampling (CVS) involves taking a small sample of the developing placenta at 10 weeks of pregnancy. The placenta, which is attached to the growing foetus by the umbilical cord, contains the DNA imprint of the baby. The placenta and its position is first assessed by ultra sound. A sample of the placenta is obtained either through the vagina or through the abdomen dependent upon where the placenta is located. The sample of placenta has its DNA then tested to see if the child's Haemoglobin making genes are affected and this determines if the baby has the full blown condition Thalassaemia Major.
  • Fetal blood sampling involves the taking of a blood sample from the umbilical cord of the foetus in the womb. Fetal blood sampling is used when the foetus has developed more and the pregnancy has advanced to 18 - 20 weeks. An affected baby will have little or no adult Haemoglobin HbA. This test is used when the CVS test cannot get access to the placenta or when the DNA test cannot determine the exact DNA profile of the baby. 
  • Amniocentesis involves taking a small sample of the amniotic fluid that surrounds the baby (between 14 -18 weeks). As there are very few cells from the baby floating about in the amniotic fluid, the test requires culturing and growing of the captured cells in the laboratory and then the DNA of these cells is tested as per the placenta test.
What is Thalassaemia? Why and What to donate?
Remedies Who can donate blood?
Tests for Thalassaemia Who cannot donate blood?
Blood Types and Compatibility History of Blood Transfusion
Go to Top
Home | Introduction | Management | Future Plans | Services | Pictures | Projects | Events
Contacts | Search | Sitemap | Email

Copyright © 2009. All rights Reserved. Site developed and maintained by JiXoft.Com