Molecular analysis and prenatal diagnosis of β thalassemias in the Saurashtra region of Gujarat

Abstract

Background: Hemoglobinopathies pose a significant health burden in the Saurashtra region in western India. Identifying couples at- risk of having a child with a severe hemoglobin disorder prenatally can help in counseling with the option of prenatal diagnosis.Methods: All pregnant carriers of β thalassemia were advised to screen their husbands. If both were carriers, they were counselled to undergo prenatal diagnosis. Prenatal diagnosis was done in 174 couples. Chorionic villus sampling was done at 10 to 12 weeks gestation and the tissue sample was sent to the Genetic laboratory for DNA analysis along with blood samples of the parents. If the couple came after 14 weeks of pregnancy, amniocentesis was done and amniotic fluid was sent for DNA analysis. If the fetus was affected, the option of termination of the pregnancy was given.Results: In 50.5% of couples, the fetus was a carrier of β thalassemia, in 1.7% the fetus had hemoglobin E trait and in 23.0% the fetus was normal. In 20.6% of couples, the fetus had β Thalassaemia major and after counseling, these couples opted for termination. 1.2% of couples had a fetus which was unaffected but remained in distinguished (normal/thalassemia carrier) while in 0.6% of cases the fetus had sickle-β thalassemia. In 1.2% of cases the result was inconclusive. In 1.2% of cases the results were not available for lack of follow up.Conclusions: Screening antenatal women for identifying carriers and referring couples at-risk for prenatal diagnosis helped in preventing the birth of 36 thalassemia major children.