Non-invasive Prenatal Diagnosis of β-Thalassemia by Detection of the Cell-Free Fetal DNA in Maternal Circulation

Abstract

β-thalassemia is one of the most frequent autosomal recessive diseases that has a high recurrence in people of the Mediterranean zone, the Middle East, India, the Far East, Tropical Africa, and the Caribbean. Parents who are both carriers for β-thalassemia have a 25% danger to give a child with β-thalassemia major, a disorder that requires a longlasting blood transfusion and costly iron-chelation treatment. The most accessible strategies for pre-birth diagnosis are chorionic villus sampling (CVS) somewhere in the range of 11 and 14 weeks and amniocentesis following 15 weeks and both are invasive procedures and cause dangers to the fetus and mother, having a danger of abortion 1 in 100-200 and 1 in 200-400, respectively. The accuracy of these methods is estimated to be 98-99%. Cell-free fetal DNA (cff-DNA) can be found in maternal plasma following 18 days from fertilized egg implantation in Pregnancies after lab conception and resembles extracellular DNA. The discovery of cff-DNA in maternal plasma has led to the evolution of noninvasive prenatal diagnosis. Some genomic loci of cff-DNA show methylated sequences unique in relation to circling maternal DNA, this trademark can be utilized to evaluate and demonstrate the presence of fetal DNA during pregnancy, independent of the sex of the embryo. the two major limitations for non-invasive prenatal diagnosis (NIPND) are the small amount of cff-DNA in maternal blood and its coexistence with maternal free DNA.we study investigations used in the detection of inherited mutation of β-thalassemia in maternal plasma during pregnancy using cell-free fetal DNA and evaluate the diagnostic test performance of cff-DNA for this issue.157