Presence of Fetal DNA in Maternal Exhaled Breath Condensate.

OBJECTIVES
Cell-free DNA (cfDNA) has been found in all body fluids, but DNAs emerging from locations that are not in direct contact with breath in exhaled breath condensate (EBC) have not yet been shown. The potential of EBC for prenatal and cancer screening prompted us to investigate whether fetal DNA is present in maternal EBC.


METHOD
20 pregnant women's EBC and blood samples were collected. Four Y chromosome-specific assays were tested on all EBC and plasma samples by quantitative PCR (qPCR). We used the best-performing assay for digital droplet PCR (ddPCR) on all EBC samples and the six plasma samples.


RESULTS
The sex of the fetuses was accurately determined from plasma samples. In EBC samples, DNA sequences could not be properly amplified by the qPCR. By ddPCR, Y chromosome sequence was amplified in two of the 11 EBC samples, from women carrying male fetuses (2/11) and the Y chromosome sequence was not amplified in the EBC of women carrying female fetuses (9/9). EBC ddPCR result's specificity was 100%, the detection rate of Y chromosome was 18.18% (2/11), and corrected accuracy was 59,09%.


CONCLUSION
Our finding "the presence of fetal DNA in maternal EBC", despite the low detection rate, might have a major impact on prenatal diagnosis and cancer screening. This article is protected by copyright. All rights reserved.