Quantitative fluorescent-polymerase chain reaction for rapid prenatal diagnosis of common aneuploidies

Abstract

Objective To evaluate the clinical value of quantitative fluorescent polymerase chain reaction (QF-PCR) in rapid prenatal diagnosis of aneuploidies. Methods Twenty-two short tandem repeats (STR) and AMXY located on chromosome 13,18,21,X and Y were used as markers to examine 1740 samples from high risk pregnant women in Down syndrome screening and advanced maternal age(≥35 yrs) by QF-PCR.Samples were also tested by karyotype analysis and the results of the two methods were compared. Results Karyotype analysis and QF-PCR results were successfully obtained from 1690 samples. All QF-PCR reports were obtained within 48 hours after sample collection.For 1639 samples,normal results were obtained by both karyotype analysis and QF-PCR.Among 51 samples that were found abnormal by karyotype analysis,41 were abnormal in QF-PCR.The rapid tests found all numerical abnormalities involving chromosome 21,18,13,X and Y in prenatal diagnosis,including trisomy 21 (n =30),trisomy 18 (n =6),45,XO (n =1 ),47,XYY (n=1),47,XXX (n=1),69,XXX (n=1) and mosaic 47,XXY[94]/46,XX[6] (n=1)(47,XXY in QF-PCR).No false positive results were found.The results obtained by QF-PCR were consistent with those of cytogenetic studies in 99.4％ of the samples (1680/1690).Only ten cases of mosain and structural abnormality could not be found (0.6％,10/1690) by QF-PCR. Conclusions Rapid QF-PCR test might diagnose all aneuploidies involving chromosome 21,18,13,X and Y.It could provide rapid and accurate diagnosis for 99.4％ pregnant women with positive Down syndrome screening and advanced maternal age. Key words: Aneuploidy; Prenatal diagnosis; Polymerase chain reaction