title: Apparent non-mosaic trisomy 16 in chorionic villi: diagnostic dilemma or clinically significant finding?
abstract: A case is presented in which apparent non-mosaic trisomy 16 was found in chorionic villi (direct and culture) obtained from a patient undergoing first-trimester prenatal diagnosis. The fetal karyotype subsequently was determined to be 46,XX by follow-up amniocentesis. Serial ultrasonographic examinations revealed placental sonolucencies and intrauterine growth retardation. At 37 weeks, a small-for-gestational-age female was delivered by Caesarean section for fetal distress. Postnatal cytogenetic studies revealed a normal female karyotype in cord blood and mosaic trisomy 16 in placental tissues. These findings suggest that in cases where aneuploidy is confined to placental tissues, it may have biological significance, as evidenced by the apparent placental dysfunction and poor fetal growth in this case.
authors.affiliation: Prenatal Diagnostic Center of Southern California, Inc., Beverly Hills 90211.
authors.forename: J
authors.initials: J
authors.lastname: Williams
authors.forename: B B
authors.initials: BB
authors.lastname: Wang
authors.forename: C H
authors.initials: CH
authors.lastname: Rubin
authors.forename: R D
authors.initials: RD
authors.lastname: Clark
authors.forename: T K
authors.initials: TK
authors.lastname: Mohandas
mesh_terms: D000328:Adult; D000649:Amniocentesis; D015193:Chorionic Villi Sampling; D002885:Chromosomes, Human, Pair 16; D005189:False Positive Reactions; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging / Q000209:etiology; D006801:Humans; D010920:Placenta / Q000000981:diagnostic imaging; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D014314:Trisomy; D014463:Ultrasonography