Prenatal detection of trisomy 18 caused by isochromosome 18p and 18q formation.
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.
van den Berg
C
C
Department of Clinical Genetics, University Hospital Dijkzigt, Erasmus University, Rotterdam, The Netherlands. vandenberg@kgen.fgg.eur.nl
Pijpers
L
L
Halley
D J
DJ
Opstal
D V
DV
Los
F J
FJ
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