title: Conflicting results of prenatal FISH with different probes for Down's Syndrome critical regions associated with mosaicism for a de novo del(21)(q22) characterised by molecular karyotyping: Case report.
abstract: For the rapid detection of common aneuploidies either PCR or Fluorescence in situ hybridisation (FISH) on uncultured amniotic fluid cells are widely used. There are different commercial suppliers providing FISH assays for the detection of trisomies affecting the Down's syndrome critical regions (DSCR) in 21q22. We present a case in which rapid FISH screening with different commercial probes for the DSCR yielded conflicting results. Chromosome analysis revealed a deletion of one chromosome 21 in q22 which explained the findings. Prenatally an additional small supernumerary marker chromosome (sSMC) was discovered as well, which could not be characterised. Postnatal chromosome analysis in lymphocytes of the infant revealed complex mosaicism with four cell lines. By arrayCGH the sSMC was provisionally described as derivative chromosome 21 which was confirmed by targeted FISH experiments.
authors.affiliation: Department of Gynecology & Obstetrics, University Hospital Schleswig-Holstein, Campus Kiel & Christian-Albrechts-University Kiel, Kiel, Germany. christel.eckmann@uk-sh.de.
authors.forename: Christel
authors.initials: C
authors.lastname: Eckmann-Scholz
authors.forename: Stefan
authors.initials: S
authors.lastname: Gesk
authors.forename: Inga
authors.initials: I
authors.lastname: Nagel
authors.forename: Andrea
authors.initials: A
authors.lastname: Haake
authors.forename: Susanne
authors.initials: S
authors.lastname: Bens
authors.forename: Simone
authors.initials: S
authors.lastname: Heidemann
authors.forename: Monika
authors.initials: M
authors.lastname: Kautza
authors.forename: Christian
authors.initials: C
authors.lastname: Timke
authors.forename: Reiner
authors.initials: R
authors.lastname: Siebert
authors.forename: Almuth
authors.initials: A
authors.lastname: Caliebe
references.citation: Am J Med Genet A. 2004 May 15;127A(1):69-73
references.pmid: 15103721
references.citation: Eur J Hum Genet. 2009 Apr;17(4):454-66
references.pmid: 19002211
references.citation: Prenat Diagn. 2001 Apr;21(4):293-301
references.pmid: 11288120
references.citation: J Histochem Cytochem. 2005 Mar;53(3):289-91
references.pmid: 15750004
references.citation: Methods Mol Biol. 2008;444:27-38
references.pmid: 18425469
references.citation: Prenat Diagn. 2001 Apr;21(4):262-9
references.pmid: 11288114
references.citation: Genet Med. 2006 Jan;8(1):1-7
references.pmid: 16418593
references.citation: Am J Hum Genet. 1997 Apr;60(4):997-9
references.pmid: 9106547
references.citation: Clin Genet. 2010 Feb;77(2):145-54
references.pmid: 19863549
references.citation: Cytogenet Genome Res. 2009;125(1):26-32
references.pmid: 19617693
references.citation: Methods Mol Biol. 2008;444:39-47
references.pmid: 18425470
references.citation: Leukemia. 2003 Nov;17(11):2214-9
references.pmid: 14523479