Genome-wide miRNA profiling in plasma of pregnant women with Down syndrome fetuses

Objective: Down syndrome (DS) belongs to the most common causes of mental retardation in men, therefore new approaches allowing its rapid and effective prenatal detection are being explored. In our study we focused on diagnostic potential of plasma microRNAs. We follow up on our previous study in DS placentas, where seven miRNAs were found as being significantly elevated. Methods: A total of 70 first-trimester plasma samples of pregnant women were included to the present study (35 samples with DS fetuses; 35 with euploid fetuses). The genome-wide miRNA profiling was performed in the preliminary study using Affymetrix GeneChipTM miRNA 4.1 Array Strips. Selected miRNAs were then included to the following validation study using qPCR. Results: Based on the current pilot study results (12 miRNAs), our previous research on CVS samples (7 miRNAs) and literature (4 miRNAs), the group of 23 miRNAs were selected for validation study. Although the results of the preliminary study were promising, the following validation step using more sensitive technology RT-PCR and larger group of samples revealed no significant differences in miRNA profiles between compared groups. Conclusion: Our results suggest that testing of the first trimester plasma miRNAs is not suitable for NIPT. Different results could be theoretically achieved at later gestational ages; however, such a result probably would have limited utilization in clinical practice.