title: Molecular detection of trisomy 21 by bicolor competitive fluorescent PCR.
abstract: OBJECTIVE
  To develop a reliable and specific method for rapid prenatal diagnosis of Trisomy 21 (Down syndrome).
  
  
  METHODS
  We established a dual color competitive fluorescent Polymerase Chain Reaction (PCR) to measure the gene dosage of Down syndrome critical region (DSCR), a single copy sequence in chromosome 21. Another unique single copy sequence located on chromosome 2 (USC2) but not glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was chose as reference gene.
  
  
  RESULTS
  The DSCR3/USC2 ratio of peripheral blood in trisomy 21 syndrome patients to normal subjects was 1.41∼1.74 to 0.93∼1.15, respectively (p < 0.01). Dual color competitive fluorescent PCR technique effectively differentiates the normal subjects from the Down syndrome patients. Next, according to the dual color competitive fluorescence quantitative PCR, among the 46 pregnant women, 3 cases were Down syndrome and 43 cases were normal, and these were confirmed by cytogenetic karyotype analysis.
  
  
  CONCLUSIONS
  This indicated that the new technique may be a reliable and specific method for the rapid prenatal diagnosis of Trisomy 21.
authors.affiliation: Faculty of Medical Sciences, Dujiangyan City Medical Center, Dujiangyan Chengdu, Sichuan, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Zhang
authors.forename: Bo
authors.initials: B
authors.lastname: Ling
authors.forename: Changxiao
authors.initials: C
authors.lastname: He
authors.forename: Qingjie
authors.initials: Q
authors.lastname: Xia
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Isamu
authors.initials: I
authors.lastname: Miyamori
authors.forename: Zhao
authors.initials: Z
authors.lastname: Yang
authors.forename: Chunyuan
authors.initials: C
authors.lastname: Fan
mesh_terms: D000653:Amniotic Fluid / Q000166:cytology; D000704:Analysis of Variance; D016022:Case-Control Studies; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics; D004314:Down Syndrome / Q000175:diagnosis / Q000235:genetics; D005260:Female; D018628:Gene Dosage / Q000235:genetics; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction / Q000379:methods*; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*