title: Differential DNA methylation as a tool for noninvasive prenatal diagnosis (NIPD) of X chromosome aneuploidies.
abstract: The demographic tendency in industrial countries to delay childbearing, coupled with the maternal age effect in common chromosomal aneuploidies and the risk to the fetus of invasive prenatal diagnosis, are potent drivers for the development of strategies for noninvasive prenatal diagnosis. One breakthrough has been the discovery of differentially methylated cell-free fetal DNA in the maternal circulation. We describe novel bisulfite conversion- and methylation-sensitive enzyme digestion DNA methylation-related approaches that we used to diagnose Turner syndrome from first trimester samples. We used an X-linked marker, EF3, and an autosomal marker, RASSF1A, to discriminate between placental and maternal blood cell DNA using real-time methylation-specific PCR after bisulfite conversion and real-time PCR after methylation-sensitive restriction digestion. By normalizing EF3 amplifications versus RASSF1A outputs, we were able to calculate sex chromosome/autosome ratios in chorionic villus samples, thus permitting us to correctly diagnose Turner syndrome. The identification of this new marker coupled with the strategy outlined here may be instrumental in the development of an efficient, noninvasive method of diagnosis of sex chromosome aneuploidies in plasma samples.
authors.affiliation: Institute of Genetics and Biophysics A. Buzzati Traverso, Naples, Italy.
authors.forename: Floriana
authors.initials: F
authors.lastname: Della Ragione
authors.forename: Paola
authors.initials: P
authors.lastname: Mastrovito
authors.forename: Ciro
authors.initials: C
authors.lastname: Campanile
authors.forename: Anna
authors.initials: A
authors.lastname: Conti
authors.forename: Elisavet A
authors.initials: EA
authors.lastname: Papageorgiou
authors.forename: Maj A
authors.initials: MA
authors.lastname: Hultén
authors.forename: Philippos C
authors.initials: PC
authors.lastname: Patsalis
authors.forename: Nigel P
authors.initials: NP
authors.lastname: Carter
authors.forename: Maurizio
authors.initials: M
authors.lastname: D'Esposito
mesh_terms: D000782:Aneuploidy; D015415:Biomarkers / Q000097:blood; D041321:Chromosomes, Human, X / Q000235:genetics*; D004247:DNA / Q000032:analysis; D019175:DNA Methylation; D005260:Female; D005333:Fetus / Q000378:metabolism / Q000502:physiology; D006801:Humans; D008297:Male; D010920:Placenta / Q000502:physiology; D011247:Pregnancy / Q000097:blood; D011296:Prenatal Diagnosis / Q000379:methods*; D025521:Tumor Suppressor Proteins / Q000097:blood / Q000235:genetics; D014424:Turner Syndrome / Q000097:blood / Q000235:genetics
chemical_list: D015415:Biomarkers; C411762:RASSF1 protein, human; D025521:Tumor Suppressor Proteins; D004247:DNA