title: PLAC4 and beta-HCG mRNA levels are not altered in the maternal circulation of pregnancies with trisomy 21.
abstract: OBJECTIVE
  Beta-human chorionic gonadotropin (HCG) and pregnancy-associated plasma protein (PAPP-A) are placentally produced proteins whose levels are altered in pregnancies with trisomy 21. PLAC4 is located on chromosome 21 and its expression is restricted to the placenta. Here we investigated whether the levels of beta-HCG-, PAPP-A- and PLAC4 mRNA could be able to discriminate pregnancies whose fetus is affected by trisomy 21.
  
  
  METHODS
  Hundred and forty-three blood samples from normal pregnancies and eight samples from trisomic pregnancies were collected. Total RNA was extracted from whole maternal blood, reverse-transcribed and the three mRNAs were quantified by real-time quantitative PCR. Hundred and nine controls were also tested for the serum levels of PAPP-A and HCG proteins.
  
  
  RESULTS
  Beta-HCG and PLAC4 mRNAs were detected in all samples, in higher amounts than in plasma, whereas the detection rate for PAPP-A mRNA was below 10%. The levels of beta-HCG mRNA significantly correlated with the circulatory concentrations of the HCG protein. However, neither beta-HCG- nor PLAC4 mRNAs show a significant difference between cases and controls.
  
  
  CONCLUSIONS
  Maternal blood levels of beta-HCG-, PLAC4- and PAPP-A mRNAs are not useful markers for the screening of pregnancies with trisomy 21 as their concentrations are either not significantly altered (beta-HCG and PLAC4) or too low to be detected (PAPP-A).
authors.affiliation: Laboratory for Prenatal Medicine and Gyn. Oncology, Department of Biomedicine and University Hospital, Basel, Switzerland.
authors.forename: Irina
authors.initials: I
authors.lastname: Banzola
authors.forename: Corinne
authors.initials: C
authors.lastname: Rusterholz
authors.forename: Letizia
authors.initials: L
authors.lastname: Zannoni
authors.forename: Nicola
authors.initials: N
authors.lastname: Rizzo
authors.forename: Xiao Yan
authors.initials: XY
authors.lastname: Zhong
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Caramelli
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Holzgreve
authors.forename: Antonio
authors.initials: A
authors.lastname: Farina
authors.forename: Sinuhe
authors.initials: S
authors.lastname: Hahn
mesh_terms: D016022:Case-Control Studies; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics; D004314:Down Syndrome / Q000097:blood / Q000235:genetics*; D005260:Female; D006801:Humans; D011247:Pregnancy; D011266:Pregnancy-Associated Plasma Protein-A / Q000096:biosynthesis* / Q000235:genetics; D011296:Prenatal Diagnosis / Q000379:methods*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D012333:RNA, Messenger; D011266:Pregnancy-Associated Plasma Protein-A