Baig S, Ho SSY, Ng BL, Chiu L, Koay ESC, Leow GH, Gole L, Kothandaraman N, Chan J, Sun X, Chan YH, Rauff M, Su LL, Biswas A, Choolani M
Correspondence: A/Prof Mahesh Choolani, obgmac@nus.edu.sg
ABSTRACT
Introduction We aimed to develop a rapid quantitative-fluorescence polymerase chain reaction (QF-PCR) to detect common foetal aneuploidies in the Singapore population within 48 hours of sample collection in order to alleviate parental anxiety.
Methods DNA from 1,000 foetal samples (978 amniotic fluids, 14 chorion villi and eight foetal blood samples) was analysed using a QF-PCR of 19 microsatellite markers located on chromosomes 13, 18, 21, X and Y. A total of 523 samples were archived before the QF-PCR analysis (archived), while QF-PCR was performed and the results obtained within 48 hours of sample collection in the remaining 477 samples (live). The results were confirmed with their respective karyotypes.
Results In total, 47 autosomal trisomies (T) were found: 30 among the archived (three T13, 12 T18, 15 T21) and 17 among the live (four T18, 13 T21) samples. The QF-PCR results were verified with their respective karyotypes. We achieved 100 percent sensitivity (lower 95 percent confidence interval [CI], 92.8 percent) and specificity (lower 95 percent CI, 99.5 percent), and the time taken from sample collection to the obtaining of results for the 477 live samples was less than 48 hours.
Conclusion Prenatal diagnostic results of common chromosomal abnormalities can be released within 48 hours of sample collection using QF-PCR. Parental anxiety is alleviated and clinical management is enhanced with this short waiting time.
Keywords: amniocentesis, Down syndrome, FISH, karyotype, short tandem repeat
Singapore Med J 2010; 51(4): 343-348
