Non-invasive prenatal testing for sex chromosome abnormalities: a source of confusion

Kalafat, Erkan; Seval, Mehmet Murat; Turgay, Batuhan; Koç, Acar

doi:10.1136/bcr-2014-207309

Cited by 11 publications

(12 citation statements)

References 15 publications

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“…In some cases, such as laboratory error, this will be an unnecessary concern which causes anxiety and may lead to unanticipated interventions. In other cases, true discordance between genetic and phenotypic sex will be identified, and conditions including hypospadias, androgen insensitivity, and congenital adrenal hyperplasia may be suspected early in pregnancy in an apparently normal fetus in whom this diagnosis would not have otherwise been made [17][18][19]. Similarly, the situation of indeterminate sex at birth will now be possible to anticipate and clarify by means of fetal karyotyping, enabling counselling and preparation prior to birth.…”

Section: Discussionmentioning

confidence: 99%

Non-Invasive Prenatal Testing for Sex Chromosome Aneuploidy in Routine Clinical Practice

Kornman

Palma-Dias

Nisbet³

et al. 2017

Fetal Diagn Ther

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Objectives: To assess the accuracy of non-invasive prenatal testing (NIPT) for sex chromosome aneuploidy (SCA) in routine clinical practice and to review counselling and sonographic issues arising in SCA cases. Methods: Three specialist Australian obstetric ultrasound and prenatal diagnosis practices offering NIPT after 10 weeks' gestation participated in this study. NIPT was reported for chromosomes 21, 18, 13, X, and Y. Results: NIPT screening was performed in 5,267 singleton pregnancies. The odds of being affected given a positive screening result (OAPR) was lowest for SCAs, most notably for monosomy X (20%). Fewer women underwent invasive prenatal testing when counselled regarding a high risk for SCA (65.5%) compared with those who had a high risk for another aneuploidy (85%). The positive screening rate of NIPT including SCA was 2.3%, but 1.2% if only the autosomal trisomies were included in the panel. Conclusion: The addition of SCA testing to NIPT doubles the positive screening rate. The OAPR for SCAs (most notably for monosomy X) is reduced compared with the autosomal trisomies. Clinicians need a more extensive discussion with women prior to the inclusion of the X and Y chromosomes in the NIPT panel, given the complexity in counselling regarding further management and the additional anxiety that these abnormal results may cause. A benefit of sex chromosome analysis is an improvement in antenatal diagnosis of some disorders of sexual development.

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Section: Discussionmentioning

confidence: 99%

Non-Invasive Prenatal Testing for Sex Chromosome Aneuploidy in Routine Clinical Practice

Kornman

Palma-Dias

Nisbet³

et al. 2017

Fetal Diagn Ther

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“…She was offered an amniocentesis, which revealed a euploid fetus with no sex-chromosome abnormalities. Even with single nucleotide polymorphism (SNP)-based NIPT, positive predictive value for detection of sex-chromosome abnormalities is around 50 % [19]. Positive results of NIPT should be heeded with caution, and an invasive diagnostic procedure should be performed, especially for rare chromosomal abnormalities and sex-chromosome abnormalities where NIPT performs sub-par compared with its performance for detection of trisomy 21 [19].…”

Section: Discussionmentioning

confidence: 99%

Has Noninvasive Prenatal Testing (NIPT) Come of Age?

Allahbadia

2015

J Obstet Gynecol India

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“…The PPV for 45,X is approximately 40%, for 47,XYY it is 25%, and for 47,XXY and 47,XXX it ranges from 25%–75% based on maternal age (Gil, Quezada, Revello, Akolekar, & Nicolaides, ). It is therefore difficult to counsel patients with a positive result, many of whom may think that the chances of an affected pregnancy are much higher based on detection rate alone (Kalafat, Seval, Turgay, & Koc, ).…”

Section: Introductionmentioning

confidence: 99%

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

Fleddermann

Hashmi

Stevens

et al. 2019

Journal of Genetic Counseling

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The purpose of this study was to describe current genetic counseling practice in the United States following a non‐invasive prenatal testing (NIPT) result positive for a sex chromosome abnormality (SCA). Screening for SCAs can be confounded by confined placental mosaicism, natural loss of the X chromosome from maternal cells during aging, and undiagnosed maternal SCA or copy number variant (CNV). Furthermore, with the exception of 45,X, individuals with SCAs usually have no ultrasound or postnatal findings. This makes follow‐up for unresolved positive NIPT necessary; however, there are currently no clinical guidelines. This study used a cross‐sectional design with an anonymous questionnaire to survey 176 genetic counselors. The majority of prenatal respondents always offered diagnostic testing (>88%) and anatomy ultrasound (~90%), but the percent consistently offering maternal karyotype (22%–52%) and postnatal evaluation (28%–87%) varied. Maternal karyotype was offered more often when NIPT was positive for 45,X or 47,XXX and patients had normal prenatal diagnostic testing (p < 0.02) or declined testing (p < 0.02). Offer of postnatal evaluation was more likely when diagnostic testing was declined (p < 0.001). The majority of pediatric providers always offered a postnatal karyotype for the newborn (>72%) but the percent offering maternal karyotype (6%–46%) varied widely. With the current inconsistencies, many newborns with undiagnosed SCAs who could benefit from growth hormone therapy, early intervention, and/or targeted surveillance may be missed. Therefore, there is a need for professional guidelines to help improve the consistency of clinical care for patients with NIPT results positive for SCAs.

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Non-invasive prenatal testing for sex chromosome abnormalities: a source of confusion

Cited by 11 publications

References 15 publications

Non-Invasive Prenatal Testing for Sex Chromosome Aneuploidy in Routine Clinical Practice

Non-Invasive Prenatal Testing for Sex Chromosome Aneuploidy in Routine Clinical Practice

Has Noninvasive Prenatal Testing (NIPT) Come of Age?

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

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