title: Non-invasive fetal sex determination using real-time PCR.
abstract: OBJECTIVE
  The aim of this study was to evaluate the specificity and sensitivity of the real-time quantitative PCR method for fetal gender determination in early pregnancy.
  
  
  METHODS
  Blood samples were collected from 46 pregnant women prior to amniocentesis. DNA was extracted from maternal plasma using a QIAmp DNA Blood Mini Kit. DNA samples were subjected to real-time quantitative PCR amplification of SRY (as a fetus-specific marker) and beta-globin (as a marker for total plasma DNA) genes.
  
  
  RESULTS
  The beta-globin gene sequence was detected in all samples. The SRY gene was detected in 25 of 28 plasma samples from women with male fetuses and in none of the 18 samples from women with female fetuses (sensitivity 89.2% and specificity 100%). The fetal gender was correctly determined in 43 (93.5%) of 46 maternal plasma samples. The concentration of the beta-globin gene ranged from 161 to 25,568 genome-equivalents (GE)/mL (median 1051.1), while the concentration of the SRY gene ranged from 5 to 166 GE/mL (median 27.4). The percentage of free fetal DNA ranged from 0.1% to 46.1% (median 2.0%).
  
  
  CONCLUSIONS
  Amplification of fetal DNA from maternal plasma by real-time quantitative PCR is a promising method for fetal sex determination in early pregnancy. However, further studies are necessary before this procedure can be included into a clinical routine.
authors.affiliation: Research Center for Genetic Engineering and Biotechnology, Macedonian Academy of Sciences & Arts, Skopje, Republic of Macedonia.
authors.forename: Katarina
authors.initials: K
authors.lastname: Davalieva
authors.forename: Pavle
authors.initials: P
authors.lastname: Dimcev
authors.forename: Georgi D
authors.initials: GD
authors.lastname: Efremov
authors.forename: Dijana
authors.initials: D
authors.lastname: Plaseska-Karanfilska
mesh_terms: D041322:Chromosomes, Human, Y / Q000235:genetics*; D004247:DNA / Q000032:analysis*; D017931:DNA Primers; D005260:Female; D005914:Globins / Q000235:genetics*; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction / Q000379:methods; D011237:Predictive Value of Tests; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012680:Sensitivity and Specificity; D012732:Sex Determination Analysis / Q000379:methods*; D051876:Sex-Determining Region Y Protein / Q000235:genetics*
chemical_list: D017931:DNA Primers; D051876:Sex-Determining Region Y Protein; D005914:Globins; D004247:DNA