[Impact of maternal X chromosome aneuploidies on cell free DNA prenatal screening].

Abstract

Objective: To investigate the impact of maternal X chromosome aneuploidies on cell free DNA (cf-DNA) prenatal screening. Methods: After genetic counseling, invasive prenatal diagnosis was provided for the 124 cases with high risk of sex chromosome aneuploidie (SCA) indicated by cf-DNA prenatal screening. For cases with discordant results of fetal prenatal diagnosis and cf-DNA prenatal screening, maternal leukocyte was collected for copy number variation sequencing (CNV-seq) to detect whether the maternal X chromosome was carrying variations. Results: Totally, 124 cases with high risks of SCA indicated by cf-DNA prenatal screening, 9 cases refused to take invasive prenatal diagnosis, while the remaining 115 cases received. Among the 115 cases, 41 cases received accordant results with cf-DNA prenatal screening while 74 cases discordant. Among the 74 cases with discordant results, 19 cases were indicated with maternal X chromosome variations by maternal leukocyte CNV-seq, which accounting for 25.7% (19/74) of the SCA false positive cases, and 15.3% (19/124) of all SCA cases. Conclusions: Pregnant women with X chromosome variations may affect the results of cf-DNA prenatal screening, resulting in false positive or false negative outcomes, it should be emphasized that the cf-DNA results may be affected by maternal X chromosome variations. In cases with discordant results of prenatal diagnosis and cf-DNA prenatal screening, maternal leukocyte CNV-seq is recommended to find the reasons of false positive or negative results. And cf-DNA prenatal screening is not recommended for pregnant women who are already known with X chromosome variations.

• Authors: J Z Chang, Q W Qi, X Y Zhou, Y L Jiang, N Hao, J Zhou, M M Li, X T Tian, J T Liu
• Journal: Zhonghua fu chan ke za zhi (Zhonghua Fu Chan Ke Za Zhi) Vol. 55 Issue 2 Pg. 100-105 (Feb 25 2020) ISSN: 0529-567X [Print] China
• PMID: 32146738 (Publication Type: Journal Article)

Chemical References

• Cell-Free Nucleic Acids

Topics

• Aneuploidy
• Cell-Free Nucleic Acids (blood)
• Chromosome Disorders
• Chromosomes, Human, X (genetics)
• DNA Copy Number Variations (genetics)
• Female
• Humans
• Maternal Serum Screening Tests (methods)
• Pregnancy
• Prenatal Diagnosis (methods)
• Sex Chromosome Disorders (genetics)