Noninvasive prenatal diagnosis experience in the Çukurova Region of Southern Turkey: detecting paternal mutations of sickle cell anemia and [beta]-thalassemia in cell-free fetal DNA using high-resolution melting analysis

Objective This study used a high-resolution melting (HRM) technique to detect paternal mutations for the noninvasive prenatal diagnosis (NIPD) of [beta]-thalassemia and sickle cell anemia (HbS). We also determined the levels of cell-free fetal DNA and total cell-free DNA. Methods We used the HRM technique for fetal genotyping of paternal mutations in maternal plasma from 32 pregnancies at risk of [beta]-thalassemia and 57 pregnancies at risk of HbS. The DNA levels in maternal plasma were measured using real-time quantitative PCR. Multiples of the median (MoM) values were calculated in women at risk for [beta]-thalassemia or HbS. Results Twenty-two paternal mutations were detected in 89 pregnant women. Although we were successfully able to detect the paternal [beta]-thalassemia mutations, the mutant HbS fetuses could not be distinguished from maternal background in the early weeks of pregnancy. The detection of DYS14 in male fetuses was 100%. The MoM values of women at high risk of having HbS-affected fetuses were higher than those for the other groups. Conclusion High-resolution melting is a useful method for NIPD of [beta]-thalassemias by detecting paternal mutations in the maternal plasma. Cell-free fetal DNA quantification and MoM values were not informative for HbS or [beta]-thalassemias in early pregnancy. © 2013 John Wiley & Sons, Ltd. What's already known about this topic? The noninvasive prenatal detection of paternal mutations in [beta]-thalassemias is achievable using a high-resolution melting technique with cell-free fetal DNA. This is the first study from Turkey to test the diagnostic performance and practical applicability of this technique in a clinical setting. What does this study add? The high-resolution melting technique is useful for detection of paternal mutations of [beta]-thalassemias and for detection during the early stage of pregnancy using cell-free fetal DNA. This analysis reduces the risk for a double heterozygous fetus without using an invasive method such as chorionic villus sampling. [PUBLICATION ABSTRACT]