Anno:
2021
Cell‐free DNA screening for fetal aneuploidy using the rolling circle method: A step towards non invasive prenatal testing simplification
Enza Pavanello, Andrea Sciarrone, Varvara Guaraldo, Elisabetta Muccinelli, Valentina Pia Ciuffreda, Pina Sauro, Giulia Bondielli, Sandra Mirante, Giulio Mengozzi, Elsa Viora, Howard Cuckle, Barbara Pasini
Prenat Diagn. 2021 Dec;41(13):1694-1700. doi: 10.1002/pd.6050. Epub 2021 Oct 7.
Abstract
Objective: To assess the efficacy of cell-free (cf)DNA screening for aneuploidy using the automated system based on rolling circle replication.
Methods: A prospective study among women referred for invasive prenatal diagnosis between July 2018 and December 2019. The plasma fraction was extracted within 5 days from blood collection, stored at -20°C and cfDNA measured between January and December 2019.
Results: A total of 805 women were recruited; 778 with singleton pregnancies and 27 twins. There were 48 Down syndrome, 25 Edwards syndrome and 3 Patau syndrome cases. Overall, the no-call rate was 2.6% (95% confidence interval 1.6%-3.9%) which reduced from 4.7% to 1.1% after relocation of the system (p < 0.002) to ensure a constant ambient temperature below 25°C. In singletons the Down syndrome detection rate (DR) was 100% (93%-100%) and false-positive rate (FPR) 0.14% (0.00%-0.79%). The Edwards syndrome DR was 96% (80%-100%) and FPR 0.78% (0.29%-1.7%). One false-positive had a confined placental trisomy 18 and the remaining five a z-score requiring sample repetition; all the false-positives occurred before system relocation (p < 0.005). Patau syndrome DR and FPR were 67% (9.4%-99%) and 0.26% (0.03%-0.95%).
Conclusion: The cfDNA rolling circle method yields similar results to other methods provided that room temperature is adequately controlled.
