Prenatal diagnosis of a true fetal tetraploidy in direct and cultured chorionic villi.
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.
Schluth
C
C
Laboratoire de Cytogénétique, Hôpital de Hautepierre, 67098 Strasbourg, France.
Doray
B
B
Girard-Lemaire
F
F
Favre
R
R
Flori
J
J
Gasser
B
B
Rudolf
G
G
Flori
E
E
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