Current genetic counseling practice in the United States following positive non‐invasive prenatal testing for sex chromosome abnormalities

Objective: This study was designed to investigate the efficiency of noninvasive prenatal testing (NIPT) for screening fetal sex chromosome aneuploidies (SCAs) through sequencing of cell-free DNA in maternal plasma. Methods: This is a retrospective study on the positive NIPT results for SCAs collected from our hospital between January 2012 and December 2018. Samples with positive NIPT results for SCAs were then confirmed by prenatal or postnatal karyotyping analysis. Results: After cytogenetic analysis, abnormal karyotypes were confirmed in 104 cases and the overall positive predictive value (PPV) of NIPT for SCAs was 43.40% (102/235). The most frequently detected karyotypes included 47,XXY (n = 42), 47,XXX (n = 20), 47,XYY (n = 16), and 45,X (n = 2). Meanwhile, 10 cases were confirmed with mosaic karyotype 45,X/46,XX and 14 cases with numerical or structural chromosome abnormalities, including a double trisomy 48,XXX,+18. Cytogenetic results from the other 131 cases showed normal XX or XY, which were discordant with NIPT results. Upon analysis of parental karyotypes, 29 (12.34%) showed false positivity in NIPT results that were caused by maternal sex chromosome abnormalities. Conclusion: NIPT is an effective screening tool for SCA with a PPV of 43.40%. Maternal karyotype abnormalities occurred in 12.34% of the cases with abnormal NIPT. Diagnostic testing of the fetus and the mother are recommended.

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Current status of non-invasive prenatal testing (NIPT): genetic counseling, dominant methods and overall performance

LaboratoriumsMedizin ◽

10.1515/labmed-2016-0038 ◽

2016 ◽

Vol 40 (5) ◽

Author(s):

Thomas Harasim ◽

Imma Rost ◽

Hanns-Georg Klein

Keyword(s):

Genetic Counseling ◽

Paradigm Shift ◽

Sex Chromosome ◽

Prenatal Testing ◽

Diagnostic Procedures ◽

Trisomy 13 ◽

Current Status ◽

Non Invasive ◽

Overall Performance ◽

Aneuploidy Testing

Abstract:The introduction of non-invasive prenatal testing (NIPT) into prenatal care represents a paradigm shift. With the absence of any intervention risk in contrast to invasive diagnostic procedures, NIPT has been widely adopted for the detection of fetal trisomy 13, 18 and 21. Additionally, fetal sex chromosome aneuploidy testing and sex determination are available, but can be compromised by both, medical and legal factors. Available validation studies were predominantly based on patients with a high

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Cell-Free DNA Screening for Sex Chromosome Abnormalities and Pregnancy Outcomes, 2018–2020: A Retrospective Analysis

Journal of Personalized Medicine ◽

10.3390/jpm12010048 ◽

2022 ◽

Vol 12 (1) ◽

pp. 48

Author(s):

Yanmei Lu ◽

Shihao Zhou ◽

Siyuan Linpeng ◽

Siyi Ding ◽

Shihong Li ◽

...

Keyword(s):

Pregnancy Outcomes ◽

Sex Chromosome ◽

Chromosome Abnormalities ◽

Fetal Diagnosis ◽

Fetal Sex ◽

Non Invasive ◽

Total Incidence ◽

Sex Chromosome Abnormalities ◽

Structural Abnormalities

To evaluate the efficacy of non-invasive prenatal screening (NIPT) for detecting fetal sex chromosome abnormalities, a total of 639 women carrying sex chromosome abnormalities were selected from 222,107 pregnant women who participated in free NIPT from April 2018 to December 2020. The clinical data, prenatal diagnosis results, and follow-up pregnancy outcomes of participants were collected. The positive predictive value (PPV) was used to analyze the performance of NIPT. Around 235 cases were confirmed with sex chromosome abnormalities, including 229 cases with sex chromosome aneuploidy (45, X (n = 37), 47, XXX (n = 37), 47, XXY (n = 110), 47, XYY (n = 42)) and 6 cases with structural abnormalities. The total incidence rate was 0.11% (235/222,107). The PPV of NIPT was 45.37% (235/518). NIPT accuracy for detecting sex chromosome polysomes was higher than that for sex chromosome monomers. The termination of pregnancy rate for fetal diagnosis of 45, X, and 47, XXY was higher than that of 47, XXX, and 47, XYY. The detection rate of fetal sex chromosome abnormalities was higher in 2018–2020 than in 2010–2012 (χ2 = 69.708, P < 2.2 × 10−16), indicating that NIPT is greatly efficient to detect fetal sex chromosome abnormalities.

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