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Case Reports
. 2011 Oct;170(10):1325-7.
doi: 10.1007/s00431-011-1491-9. Epub 2011 May 18.

Tetrasomy and pentasomy of the X chromosome

Edith Schoubben  1 , Karin Decaestecker, Koen Quaegebeur, Lode Danneels, Geert Mortier, Luc Cornette
Affiliations
Case Reports

Tetrasomy and pentasomy of the X chromosome

Edith Schoubben et al. Eur J Pediatr. 2011 Oct.

Abstract

We describe a newborn girl with a life-threatening laryngomalacia and extreme hypotonia. Genetic analysis revealed the very rare genetic condition mosaicism of 48,XXXX and 49,XXXXX (50/50). We here state that the degree of early hypotonia constitutes an important early prognostic feature in this syndrome. The timely insertion of a gastrostomy is warranted in order to prevent aspiration.

Conclusion: A karyotype is mandatory in female newborns with moderate to severe hypotonia in order to exclude polyploid mosaicism of the X chromosome. An 'overall prognosis' for 48,XXXX and 49,XXXXX girls is difficult to provide towards parents in line with a well-known, substantial variability in outcome for all polysomy X infants.

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References

    1. J Pediatr. 1963 Dec;63:1099-103 - PubMed
    1. Can Med Assoc J. 1961 Jan 21;84:131-7 - PubMed
    1. Eur J Pediatr. 2010 Oct;169(10):1255-61 - PubMed
    1. Cytogenetics. 1968;7(4):249-59 - PubMed
    1. Pediatrics. 1995 Oct;96(4 Pt 1):672-82 - PubMed

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