title: Prenatal detection of trisomy 18 caused by isochromosome 18p and 18q formation.
abstract: We report on the prenatal detection and further genetic studies in a case of trisomy 18 caused by isochromosome 18p [i(18p)] and 18q [i(18q)] formation. The diagnosis was made by standard cytogenetic techniques in amniotic fluid cells and confirmed by fluorescence in situ hybridization. The formation of the isochromosomes cannot be explained by a single model; centromere misdivision and meiosis II nondisjunction without recombination or mitotic misdivision are the most likely mechanisms of formation as indicated by DNA analysis.
authors.affiliation: Department of Clinical Genetics, University Hospital Dijkzigt, Erasmus University, Rotterdam, The Netherlands. vandenberg@kgen.fgg.eur.nl
authors.forename: C
authors.initials: C
authors.lastname: van den Berg
authors.forename: L
authors.initials: L
authors.lastname: Pijpers
authors.forename: D J
authors.initials: DJ
authors.lastname: Halley
authors.forename: D V
authors.initials: DV
authors.lastname: Opstal
authors.forename: F J
authors.initials: FJ
authors.lastname: Los
mesh_terms: D000328:Adult; D002887:Chromosomes, Human, Pair 18 / Q000235:genetics*; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D018404:Isochromosomes / Q000235:genetics*; D011247:Pregnancy; D011296:Prenatal Diagnosis; D014314:Trisomy