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Case Reports
. 2022 Sep 26:13:926290.
doi: 10.3389/fgene.2022.926290. eCollection 2022.

Case Report: How whole-genome sequencing-based cell-free DNA prenatal testing can help identify a marker mhromosome

Pascale Kleinfinger  1 , Marie Brechard  2 , Armelle Luscan  1 , Detlef Trost  1 , Aicha Boughalem  1 , Mylene Valduga  1 , Stéphane Serero Dr  1 , Jean-Marc Costa  1 , Laurence Lohmann  1
Affiliations
Case Reports

Case Report: How whole-genome sequencing-based cell-free DNA prenatal testing can help identify a marker mhromosome

Pascale Kleinfinger et al. Front Genet. .

Abstract

A supernumerary marker chromosome (SMC) is a structurally abnormal chromosome that cannot be characterized by conventional banding cytogenetics. Marker chromosomes are present in 0.075% of prenatal cases. They are associated with variable phenotypes, ranging from normal to severely abnormal, and the prognosis is largely dependent on the results of further cytogenomic analysis. Here, we report the identification and characterization of a marker chromosome following prenatal screening in a 39-year-old pregnant patient. The patient had a normal first trimester ultrasound but was high-risk for fetal chromosome anomalies based on the results of maternal serum parameters. Chorionic villus sampling was performed, and analysis of chorionic villi revealed the presence of two identical marker chromosomes. In the interest of a rapid identification of the markers, we performed noninvasive prenatal testing (NIPT) together with chorionic villus sampling. A pericentromeric 29 Mb duplication of chromosome 20: dup (20) (p13q11.21) was identified and thereafter confirmed by targeted metaphasic FISH. Whole-genome sequencing-based NIPT was instrumental in rapid characterization of the SMCs and allowed us to obviate the need for multiple expensive and time-consuming FISH analyses.

Keywords: array; case report; fish; noninvasive prenatal testing; supernumerary marker chromosome.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

FIGURE 1
FIGURE 1
Identification of the marker chromosomes with direct examination of the cytotrophoblast following CVS [revealed two supplementary and identical SMCs (48,XX,+marx2)].
FIGURE 2
FIGURE 2
Identification of the marker chromosomes with interphasic FISH using centromeric probe of chromosome 20 (showing tetrasomy 20 in 20% of nuclei; lens 100X).
FIGURE 3
FIGURE 3
Patient’s analysis workflow by weeks of amenorrhea. US, ultrasound; MSS, maternal serum screen, CVS, chorionic villus sampling, NIPT, noninvasive prenatal testing; FISH, fluorescence in situ hybridization.
See this image and copyright information in PMC

References

    1. Crolla J. A. (1998). FISH and molecular studies of autosomal supernumerary marker chromosomes excluding those derived from chromosome 15: II. Review of the literature. Am. J. Med. Genet. 75 (4), 367–381. 10.1002/(sici)1096-8628(19980203)75:4<367::aid-ajmg5>3.0.co;2-n - DOI - PubMed
    1. Fiorentino F., Bono S., Pizzuti F., Duca S., Polverari A., Faieta M., et al. (2017). The clinical utility of genome-wide non invasive prenatal screening. Prenat. Diagn. 37 (6), 593–601. 10.1002/pd.5053 - DOI - PubMed
    1. Flowers N. J., Burgess T., Giouzeppos O., Shi G., Love C. J., Hunt C. E., et al. (2020). Genome-wide noninvasive prenatal screening for carriers of balanced reciprocal translocations. Genet. Med. 22 (12), 1944–1955. 10.1038/s41436-020-0930-2 - DOI - PubMed
    1. Grati F. R. (2014). Chromosomal mosaicism in human feto-placental development: Implications for prenatal diagnosis. J. Clin. Med. 3 (3), 809–837. 10.3390/jcm3030809 - DOI - PMC - PubMed
    1. Grati F. R., Malvestiti F., Gallazzi G., Saragozza S., Grimi B., Agrati C., et al. (2021). Performance of conventional cytogenetic analysis on chorionic villi when only one cell layer, cytotrophoblast or mesenchyme alone, is analyzed. Prenat. Diagn. 41 (6), 652–660. 10.1002/pd.5941 - DOI - PubMed

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