Abstract (eng)
Prenatal diagnosis can be challenging, particularly in the early stages of pregnancy, where direct genomic fetal DNA extraction is impossible. However, by integrating cell-free fetal DNA (cffDNA) from amniotic fluid, results can be expedited, delays can be prevented, and the need for additional punctures can be eliminated in case of cell culture failure. Our research has identified a correlation between gestational age and the concentration of cff-DNA. While higher concentrations can be achieved in later stages, earlier weeks of pregnancy often require a concentration step for DNA-intensive methods. The study also discovered a significant finding in preventing maternal cell contamination through centrifugation. This method was tested on 34 visibly blood-tinged amniotic fluids and was proven effective through STRMarker analysis. Maternal cells, such as lymphocytes, can release maternal DNA during lysis during DNA extraction, leading to misinterpretation of results in the worst-case scenario. The study used different molecular techniques on 162 patient samples, including Array Comparative Genomic Hybridization, Multiplex Ligation-Dependent Probe Amplification, Sanger sequencing, and Whole Exome Sequencing. The results showed that all methods could be successfully adapted to work with cff-DNA with specific protocols, achieving 100% concordance with the gf-DNA routine diagnostic results. Our research presents a new method for extracting cffDNA from amniotic fluid, enabling immediate prenatal diagnosis before 20 weeks of pregnancy, significantly reducing the time required for diagnosis and improving clinical decision-making, benefiting healthcare professionals and patients.