A false-positive diagnosis of Turner syndrome by amniocentesis.
A 45,X karyotype was observed in all cells examined from an amniotic fluid sample taken at 16 weeks' gestation from a 37-year-old patient referred because of her age. Following termination of the pregnancy, all cells examined from fetal tissues (cardiac blood, skin, and muscle) showed a 46,XX karyotype. The most likely explanation for the discordant results is thought to be a dizygotic twin pregnancy with a normal fetus and an empty sac, the latter being sampled at amniocentesis resulting in a 45,X karyotype.
Griffiths
M J
MJ
Regional Genetics Laboratory, Birmingham Maternity Hospital, U.K.
Miller
P R
PR
Stibbe
H M
HM
D000328:Adult; D000649:Amniocentesis / Q000592:standards*; D000653:Amniotic Fluid / Q000166:cytology; D002503:Centromere / Q000235:genetics; D005189:False Positive Reactions; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis* / Q000196:embryology; D005327:Fetal Resorption; D005817:Genetic Counseling; D005865:Gestational Age; D006801:Humans; D017403:In Situ Hybridization; D007621:Karyotyping; D011247:Pregnancy; D014424:Turner Syndrome / Q000175:diagnosis* / Q000196:embryology; D014429:Twins, Dizygotic