title: Prenatal diagnosis of a true fetal tetraploidy in direct and cultured chorionic villi.
abstract: Prenatal diagnosis of a true fetal tetraploidy in direct and cultured chorionic villi: Tetraploidy is characterized by four complete sets of chromosomes (4n= 92). Although it has been frequently reported in spontaneous abortions, tetraploidy is extremely rare in term pregnancy. Most of late surviving patients are diploid/tetraploid mosaics and present severe mental and physical impairment. Up to date, only five tetraploidies were ascertained in the prenatal stage in amniocytes and/or fetal blood lymphocytes. No one has been reported in chorionic villi probably because tetraploidy is generally considered in this tissue as a false positive result due to confined placental mosaicism (CPM) or placental culture artefacts. We report here on a case of tetraploidy detected in chorionic villi because of fetal cystic hygroma. We discuss the reliability of this diagnosis and propose guidelines in the follow-up of tetraploidies detected after chorionic villus sampling (CVS). Thus a misdiagnosis of this poor condition will be avoided at best and an appropriate genetic counseling will be given to the parents.
authors.affiliation: Laboratoire de Cytogénétique, Hôpital de Hautepierre, 67098 Strasbourg, France.
authors.forename: C
authors.initials: C
authors.lastname: Schluth
authors.forename: B
authors.initials: B
authors.lastname: Doray
authors.forename: F
authors.initials: F
authors.lastname: Girard-Lemaire
authors.forename: R
authors.initials: R
authors.lastname: Favre
authors.forename: J
authors.initials: J
authors.lastname: Flori
authors.forename: B
authors.initials: B
authors.lastname: Gasser
authors.forename: G
authors.initials: G
authors.lastname: Rudolf
authors.forename: E
authors.initials: E
authors.lastname: Flori
mesh_terms: D000649:Amniocentesis; D015193:Chorionic Villi Sampling; D002869:Chromosome Aberrations; D017809:Fatal Outcome; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000235:genetics*; D017408:Guidelines as Topic; D006801:Humans; D007621:Karyotyping; D018191:Lymphangioma, Cystic / Q000175:diagnosis / Q000196:embryology / Q000235:genetics; D008297:Male; D009030:Mosaicism; D010920:Placenta / Q000166:cytology; D011123:Polyploidy; D011247:Pregnancy; D011248:Pregnancy Complications; D015203:Reproducibility of Results; D014463:Ultrasonography