title: Prenatal diagnosis of fragile X syndrome by placental (chorionic villi) biopsy culture.
abstract: Second trimester ultrasound-guided fetal blood sampling and placental biopsy were performed on 10 pregnancies at risk for fra(X)-linked mental retardation (Martin-Bell syndrome). Three cases were diagnosed as affected after cytogenetic analysis of fetal blood and placental cultures. The fra(X)(q27.3) and common fragile sites were shown to be expressed at a lower level in placenta than in fetal blood. Induction methods included methotrexate, 5-fluoro-2-deoxyuridine, and excess thymidine. Excess thymidine may give the best expression of fra(X)(q27.3). Enhancement of fra(X)(q27.3) expression was not shown with caffeine or 5-methoxybenzamide.
authors.affiliation: Harris Birthright Research Centre for Fetal Medicine, London, England.
authors.forename: M J
authors.initials: MJ
authors.lastname: McKinley
authors.forename: L U
authors.initials: LU
authors.lastname: Kearney
authors.forename: K H
authors.initials: KH
authors.lastname: Nicolaides
authors.forename: C M
authors.initials: CM
authors.lastname: Gosden
authors.forename: T P
authors.initials: TP
authors.lastname: Webb
authors.forename: J P
authors.initials: JP
authors.lastname: Fryns
mesh_terms: D015193:Chorionic Villi Sampling; D005069:Evaluation Studies as Topic; D005260:Female; D005312:Fetal Blood / Q000166:cytology; D005600:Fragile X Syndrome / Q000175:diagnosis*; D006801:Humans; D008297:Male; D011247:Pregnancy; D011296:Prenatal Diagnosis; D012729:Sex Chromosome Aberrations / Q000175:diagnosis*; D013936:Thymidine
chemical_list: D013936:Thymidine