Prenatal Diagnosis of Sex Chromosome Abnormalities

Milunsky, Jeff M.

doi:10.1002/9781444314342.ch7

Cited by 6 publications

(3 citation statements)

References 320 publications

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“…The argument can also be made that severity of the condition, per se, should not necessarily be the determining criteria for testing. As with sex-chromosome abnormalities, prenatal detection can be justifiable because of the opportunities it provides for early therapeutic, educational and psychologic interventions (62).…”

Section: Discussionmentioning

confidence: 99%

Expanding non‐invasive prenatal testing beyond chromosomes 21, 18, 13, X and Y

Benn

2016

Clinical Genetics

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Non-invasive prenatal testing (NIPT) based on cell-free DNA in maternal plasma is being expanded to include additional chromosome abnormalities beyond those involving chromosomes 21, 18, 13, X and Y. Review of population cytogenetic data provides insight into the likely number of additional abnormalities detectable. Additional clinically significant and cytogenetically recognizable abnormalities are present in less than 0.1% of newborns but clinically significant, or potentially significant, sub-microscopic imbalances are expected to be present in 1.7%. Cytogenetic studies on chorionic villus samples suggests that after excluding abnormalities involving chromosomes 21, 18, 13, X and Y, approximately 0.6% of NIPT results may be positive for an unbalanced abnormality attributable to mosaicism but most of these will not be confirmed at amniocentesis or in newborns. NIPT has also been developed for specific microdeletion syndromes and initial experience is now available. Laboratory procedures such as deeper sequencing and additional data analytics are rapidly evolving but even with existing protocols, it is already clear that NIPT does not necessarily need to be limited to trisomies 21, 18, 13 and the sex-chromosome abnormalities. Patient educational materials and genetic counseling services need to be available for women offered expanded NIPT.

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Section: Discussionmentioning

confidence: 99%

Expanding non‐invasive prenatal testing beyond chromosomes 21, 18, 13, X and Y

Benn

2016

Clinical Genetics

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“…The 47,XYY sex chromosome complement was first reported in 1961 by Sandberg et al, 1961 in a phenotypically normal man who was evaluated chromosomally because he fathered a child with Down's syndrome. Following this report, there were numerous screenings of high-risk populations in mental and psychosocial settings (Hook, 1973;Fryns et al, 1995) as well as those with an increased risk of learning difficulties, delayed speech and language skills (Milunsky, 2004). The 47,XYY karyotype, previously considered to be rare, was found to be one of the most common chromosome abnormalities expressing itself in approximately 1:700 -1:1000 of all boys (Jacobs et al, 1974;Cohen & Durham, 1985).…”

Section: Introductionmentioning

confidence: 94%

Nonmosaic 47,XYY syndrome presenting with male infertility: case series

2011

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In this study, we describe nine patients with 47,XYY presenting with male infertility. All patients were subjected to history taking, clinical examination, duplex ultrasonographic examination of the scrotum, endocrinological investigations and cytogenetic analysis of peripheral lymphocytes. Two patients tried intracytoplasmic sperm injection (ICSI). Our results showed that seven patients were oligospermic and two patients were azoospermic. Bilateral varicocele was detected in seven patients. The hormonal levels in the majority of the patients were within normal range. Two patients showed improvement after varicocelectomy. The wife of one of the oligospermic patients became successfully pregnant after the first trial of ICSI. In conclusion, this report suggests that patients with XYY may present with primary infertility and may show oligospermia and nonobstructive azoospermia. Careful clinical, ultrasonographic, endocrinological and cytogenetic examinations should be a part of their diagnostic work-up for the proper management of these patients. In addition, ICSI may be a hope for some of these patients.

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“…Since 2013, some NIPT platforms have included sex chromosome abnormality (SCA) analysis along with the three common autosomal aneuploidies (Swanson, Sehnert, & Bhatt, 2013). As a group, SCAs are the most common chromosome abnormalities present at birth, occurring in every 1 in 300-400 live births (Milunsky, 2010). The most common SCA conditions are 45,X (Turner syndrome) and 47,XXY (Klinefelter syndrome).…”

mentioning

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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Prenatal Diagnosis of Sex Chromosome Abnormalities

Cited by 6 publications

References 320 publications

Expanding non‐invasive prenatal testing beyond chromosomes 21, 18, 13, X and Y

Expanding non‐invasive prenatal testing beyond chromosomes 21, 18, 13, X and Y

Nonmosaic 47,XYY syndrome presenting with male infertility: case series

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

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