title: Identification of universal mRNA markers for noninvasive prenatal screening of trisomies.
abstract: OBJECTIVE
  The discovery of placental transcripts in peripheral blood of pregnant women prompted us to investigate which was the most appropriate biological specimen, between plasma and serum, to easily detect them and to exploit hPL (human placental lactogen), betahCG (human chorionic gonadotrophin beta-subunit), LOC90625, and TFPI2 (tissue factor pathway inhibitor 2) levels in order to establish whether an abnormal variation degree of presence of these placental transcripts are likely to be associated to specific fetal trisomies.
  
  
  METHODS
  RNA was extracted from plasma and serum samples of 255 pregnant women bearing euploid fetuses, 17 bearing fetuses affected by trisomy 21 and 10 with fetuses affected by trisomy 18. Placental transcript analysis was performed by real time RT-PCR using relative quantification.
  
  
  RESULTS
  Results obtained from euploid samples showed that fetal transcripts were more abundant in plasma than in serum samples. Euploid samples had a placental transcript abundance distinguishable from those with trisomy 21 but not from those with trisomy 18. In particular, high betahCG abundance and advanced maternal age were significantly associated with trisomy 21 pregnancy.
  
  
  CONCLUSIONS
  Plasma was the most suitable tool to be employed in the detection and dosage of placental transcripts. betahCG transcript together with maternal age could be a potential marker for noninvasive prenatal screening of fetal trisomy 21.
authors.affiliation: Department of Obstetrics and Gynecology, Hospital S. Maria della Misericordia, University of Perugia, Perugia, Italy. CMPR-LAB@unipg.it
authors.forename: Elena
authors.initials: E
authors.lastname: Picchiassi
authors.forename: Giuliana
authors.initials: G
authors.lastname: Coata
authors.forename: Michela
authors.initials: M
authors.lastname: Centra
authors.forename: Luana
authors.initials: L
authors.lastname: Pennacchi
authors.forename: Vittorio
authors.initials: V
authors.lastname: Bini
authors.forename: Gian Carlo
authors.initials: GC
authors.lastname: Di Renzo
mesh_terms: D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood / Q000235:genetics*; D002887:Chromosomes, Human, Pair 18; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis / Q000235:genetics*; D005260:Female; D005819:Genetic Markers; D006801:Humans; D008074:Lipoproteins / Q000097:blood / Q000235:genetics*; D016015:Logistic Models; D010928:Placental Lactogen / Q000097:blood / Q000235:genetics*; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D012333:RNA, Messenger / Q000097:blood*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014314:Trisomy / Q000175:diagnosis / Q000235:genetics*
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D005819:Genetic Markers; D008074:Lipoproteins; D012333:RNA, Messenger; C051928:lipoprotein-associated coagulation inhibitor; D010928:Placental Lactogen