Thalassemia is a hereditary disease mostly seen in people of Mediterranean or Asian origin characterized by the presence of abnormal hemoglobin in their red blood cells.
Thalassemia can be broadly classified as Alpha and Beta Thalassemia depending on which part of hemoglobin is effected. Alpha Thalassemia is mostly seen in people of Asian origin and Beta Thalassemia or Cooley’s Anemia is mostly seen in people of Mediterranean origin.
It is also classified into Major and Minor Thalassemia depending on heredity. If a child inherits Thalassemic genes from both the parents it results in Thalassemia Major. If the child inherits Thalassemic genes from only one parent then he gets Thalassemia Minor. Thalassemia Minor subjects do not suffer from any symptoms and are called carriers of the disease. Carriers lead a normal life compared to any other Non-Thalassemic individual.
Symptoms of Thalassemia Major:
- Severe Anemia
- Bone deformities in the face
- Growth stunting
Thalassemia Major itself can occur as both severe, intermediate and mild forms depending on the defective genes inherited and the most severe form of Thalassemia Major results in still birth or third trimester abortion. Children born with Beta Thalassemia Major are normal at birth but develop severe anemia during the first year of life.
People with Thalassemia Major generally survive upto second or third decade of life and usually die of heart failure. Frequent blood transfusions and chelation therapy to remove excess iron can prolong their life span.
Thalassemia & Pregnency:
Known carriers and sufferers of Thalassemia have various options available to prevent their children from inheriting the defective genes.
First the Thalassemic status of the spouse should be assessed. Initially Peripheral Blood Smear Test and Complete Blood Count Test are sufficient to screen a normal individual with out any symptoms. If necessary Hemoglobin Electrophoresis is advised to confirm the diagnosis.
Once the Thalassemic status of the couple is known the odds can be calculated and necessary steps can be taken.
In any case there are three common options available to prevent Thalassemic children.
- Chorionic Villi Sampling: Once the woman is pregnant a small portion of the placenta is taken out and tested for Thalassemic genes. If the defective genes are present, then the woman is advised abortion and the process is repeated until a healthy fetus is detected and the pregnancy is continued normally. This option is more suitable when the odds are in favor of a normal baby i.e. when both the parents are carriers or one of them is a carrier and the other is normal.
- Amniocentesis: Once the woman is pregnant a small amount of fluid is extracted from the amniotic sac of the fetus and is tested for defective genes. If the defective genes are present, then the woman is advised abortion and the process is repeated until a healthy fetus is detected and the pregnancy is continued normally. This option is more suitable when the odds are in favor of a normal baby i.e. when both the parents are carriers or one of them is a carrier and the other is normal.
- In-Vitro Fertilization, Screening, Selective Implantation & Surrogate Motherhood: This process is more suitable when the odds are in favor of a Thalassemic baby i.e. when one of the parents suffers from Thalassemia Major. This is an elaborate method and is tailored to suit each couple depending on their Thalassemic status. Thalassemic mothers may not be able to sustain pregnancy depending on the severity of the disease.
Recently bone marrow transplantation is shown to result in better life expectancy in children with severe Thalassemia Major. Viral Vector based gene-therapies are being investigated for Thalassemia and it could be atleast a decade before they reach any significant milestone.