title: Beckwith-Wiedemann syndrome prenatal diagnosis by methylation analysis in chorionic villi.
abstract: Beckwith-Wiedemann syndrome (BWS) is an imprinting disorder that can be prenatally suspected or diagnosed based on established clinical guidelines. Molecular confirmation is commonly performed on amniocytes. The possibility to use fresh (CVF) and cultured (CVC) chorionic villi has never been investigated. To verify whether CVF and CVC are reliable sources of DNA to study fetal methylation, we used pyrosequencing to test the methylation level of a number of differentially methylated regions (DMRs) at several imprinted loci (ICR1, ICR2, H19, PWS/AS-ICR, GNASXL, GNAS1A, ZAC/PLAGL1, and MEST) and at non-imprinted MGMT and RASSF1A promoters. We analyzed these regions in 19 healthy pregnancies and highlighted stable methylation levels between CVF and CVC at ICR1, ICR2, GNASXL, PWS/AS-ICR, and MEST. Conversely, the methylation levels at H19 promoter, GNAS1A and ZAC/PLAGL1 were different in CVC compared to fresh CV. We also investigated ICR1 and ICR2 methylation level of CVF/CVC of 2 BWS-suspected fetuses (P1 and P2). P1 showed ICR2 hypomethylation, P2 showed normal methylation at both ICR1 and ICR2. Our findings, although limited to one case of BWS fetus with an imprinting defect, can suggest that ICR1 and ICR2, but not H19, could be reliable targets for prenatal BWS diagnosis by methylation test in CVF and CVC. In addition, PWS/AS-ICR, GNASXL, and MEST, but not GNAS1A and ZAC/PLAGL1, are steadily hemimethylated in CV from healthy pregnancies, independently from culture. Thus, prenatal investigation of genomic imprinting in CV needs to be validated in a locus-specific manner.
authors.affiliation: a Division of Pathology; Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico; Department of Pathophysiology & Transplantation; Università degli Studi di Milano ; Milano , Italy.
authors.forename: Leda
authors.initials: L
authors.lastname: Paganini
authors.forename: Nicole
authors.initials: N
authors.lastname: Carlessi
authors.forename: Laura
authors.initials: L
authors.lastname: Fontana
authors.forename: Rosamaria
authors.initials: R
authors.lastname: Silipigni
authors.forename: Silvia
authors.initials: S
authors.lastname: Motta
authors.forename: Stefano
authors.initials: S
authors.lastname: Fiori
authors.forename: Silvana
authors.initials: S
authors.lastname: Guerneri
authors.forename: Faustina
authors.initials: F
authors.lastname: Lalatta
authors.forename: Anna
authors.initials: A
authors.lastname: Cereda
authors.forename: Silvia
authors.initials: S
authors.lastname: Sirchia
authors.forename: Monica
authors.initials: M
authors.lastname: Miozzo
authors.forename: Silvia
authors.initials: S
authors.lastname: Tabano
mesh_terms: D001506:Beckwith-Wiedemann Syndrome / Q000175:diagnosis* / Q000235:genetics; D002478:Cells, Cultured; D002824:Chorionic Villi / Q000378:metabolism*; D019175:DNA Methylation; D005260:Female; D018392:Genomic Imprinting; D006801:Humans; D011247:Pregnancy; D011296:Prenatal Diagnosis; D011401:Promoter Regions, Genetic
keywords: ART; Angelman Syndrome; BWS; Assisted Reproductive Technologies; AS; Beckwith-Wiedemann Syndrome; CV; Beckwith-Wiedemann syndrome; Chorionic Villi; CVC; Cultured Chorionic Villi; CVF; DNA methylation; Differentially Methylated Regions; ICR; Fresh Chorionic Villi; DMR; Imprinting Control Region; IUGR; Intra-Uterine Growth Restriction; MMD; Multilocus Methylation Defect; PWS; Prader-Willi Syndrome; SGA; Silver Russell Syndrome; UPD; Small for Gestational Age; SRS; Ultra Sound.; Uniparental Disomy; US; chorionic villi; imprinting; prenatal diagnosis