title: Monozygotic twins with discordant karyotypes: a case report.
abstract: A monochorionic twin pregnancy had normal male karyotype on chorionic villous sampling. At delivery, one twin presented as morphologically normal, the other as trisomy 21. A twinning event and chromosome division error shortly after conception resulted in monozygotic twins with discordant tissue karyotypes and blood chromosome chimerism for trisomy 21.
authors.affiliation: Department of Neonatal Pediatrics, Royal Women's Hospital, University of Melbourne, 132 Grattan Street, Carlton, Victoria 3053, Australia. colm.odonnell@rwh.org.au
authors.forename: Colm P F
authors.initials: CP
authors.lastname: O'Donnell
authors.forename: Mark D
authors.initials: MD
authors.lastname: Pertile
authors.forename: Leslie J
authors.initials: LJ
authors.lastname: Sheffield
authors.forename: Amanda
authors.initials: A
authors.lastname: Sampson
mesh_terms: D000328:Adult; D004314:Down Syndrome / Q000097:blood / Q000235:genetics*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007621:Karyotyping; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D014430:Twins, Monozygotic / Q000235:genetics*