[Cell-free fetal DNA detection in maternal plasma using real-time PCR and cycling probe technology for prenatal screening beta-thalassaemia major].
OBJECTIVE
To analyze cell-free fetal DNA in maternal plasma for prenatal screening of beta-thalassaemia major.


METHODS
Six couples undergoing prenatal diagnosis of beta-thalassaemia (gestational age range 23-26 weeks) were enrolled in this study. The husbands were all carriers of the CD17 (A-->T) mutation, and the wives carried another beta-thalassaemia mutation. The allele-specific primers and two fluorescent cycling probes were synthesized for the detection of the CD17 (A-->T) mutation, using FAM and HEX fluorescence labeling, respectively. The cell-free fetal DNA in the maternal plasma was detected using real-time PCR, and the fetal genotype was confirmed by cord blood conventional prenatal diagnosis.


RESULTS
In the 6 pregnancies, FAM and HEX fluorescent signals were detected in 3 maternal plasma samples; in the other 3 samples, only FAM fluorescent signals were detected, suggesting the absence of paternally derived CD17 (A-->T) mutation.


CONCLUSIONS
Examination of cell-free fetal DNA in maternal plasma using real-time PCR and cycling probe technology can be effective means for prenatal screening of beta-thalassaemia major.
Chen
Xi
X
Second Clinical College of Jinan University People's Hospital of Shenzhen City, Shenzhen 518020, China.
Ren
Jing-hui
JH
Guo
Hui
H
Lin
Lin-hua
LH
Yao
Qiu-xuan
QX
D000328:Adult; D004247:DNA / Q000097:blood*; D004252:DNA Mutational Analysis; D015342:DNA Probes; D005260:Female; D005315:Fetal Diseases / Q000097:blood / Q000175:diagnosis* / Q000235:genetics; D006579:Heterozygote; D006801:Humans; D008431:Maternal-Fetal Exchange; D017354:Point Mutation; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017086:beta-Thalassemia / Q000097:blood / Q000175:diagnosis* / Q000235:genetics
D015342:DNA Probes; D004247:DNA