[Application of real-time fluorescence quantitative PCR accompanied with comparison of Delta CT for diagnosis of Down's syndrome from a single cell].
OBJECTIVE
To evaluate the use of real-time fluorescence quantitative PCR (FQ-PCR) accompanied with comparison of Delta CT as a method for diagnosis of Down's syndrome from a single cell.


METHODS
Single lymphocyte was isolated from the peripheral or umbilical cord blood samples of 22 clinically diagnosed Down's syndrome patients or fetus and 40 normal controls by micromanipulation techniques. Primer extension preamplification (PEP) and real-time FQ-PCR were used to amplify the S100B and DCSR1 located on chromosome 21, and GAPDH located on chromosome 12. Two pairs of DeltaCT values were compared between the two groups. The ratios of S100B/GAPDH and DSCR1/GAPDH products were calculated in trisomy 21 group.


RESULTS
The DeltaCT values of Down's syndrome patients were significantly lower than those of normal controls. The difference between the two groups was statistically significant (P<0.01). The ratios of S100B/GAPDH and DSCR1/GAPDH products for trisomy 21 were 1.891(1.563-2.287) and 1.840 (1.562-2.168), respectively.


CONCLUSIONS
Real-time FQ-PCR is a reliabe method that may provide a new way for non-invasive prenatal diagnosis and preimplantation genetic diagnosis for Down's syndrome.
Yu
Rong
R
Department of Gynecology and Obstetrics, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, 430030 PR China.
Chen
Han-ping
HP
Yan
Xiao-fang
XF
D002675:Child, Preschool; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis* / Q000235:genetics*; D005260:Female; D005312:Fetal Blood / Q000166:cytology / Q000378:metabolism; D006801:Humans; D007223:Infant; D008214:Lymphocytes / Q000166:cytology / Q000378:metabolism*; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods*; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity