[Significance of detecting free DNA from maternal plasma for the diagnosis of fetal chromosomal aneuploidies]

Abstract

Objective: To determine the feasibility and accuracy of detecting numerical chromosomal abnormalities by high-flux sequencing analysis of free fetal DNA from maternal plasma.

Methods: High-flux sequencing was applied to analyze fetal chromosome sequence copy numbers in 153 pregnant women. Fetal karyotyping was also carried out on amniocentesis samples.

Results: Six cases were detected with fetal chromosomal abnormalities by high-flux sequencing analysis, among which five were confirmed by karyotyping to be chromosomal aneuploidies (47,XYY; 45,X; 47,XY,+18; 47,XY,+21 and 47,XY,+13), 1 case was confirmed to be structural rearrangement, i.e., 46,XY,der(13;21)(q10;q10),+21. Furthermore, 3 chromosomal polymorphisms (one 46,XY,21p+ and two 46,XY,Yqh-) were identified. The two methods yielded similar results on fetal chromosome copy number detection.

Conclusion: High-flux sequencing analysis of free DNA derived from maternal plasma is efficient for detecting fetal chromosomal aneuploidies, and is non-invasive, highly sensitive and specific. It therefore has a broad application in antenatal diagnosis.