Quantitative real-time PCR technique for rapid prenatal diagnosis of Down syndrome.

OBJECTIVES: To develop a reliable and specific technique for rapid prenatal diagnosis of Down syndrome.
METHODS: High throughput real-time PCR technique was used to measure the DSCR3 gene dosage of genomic DNAs from uncultured amniocytes of fetuses, lymphocytes of trisomy 21 syndrome patients, and normal people, compared to conventional cytogenetic karyotype analysis.
RESULTS: The DSCR3/GAPDH ratio of uncultured amniocytes in trisomy 21 syndrome fetuses to normal fetuses was 1.69 +/- 0.17 to 1.06 +/- 0.14, respectively (p < 0.001); and the DSCR3/GAPDH ratio of lymphocytes in trisomy 21 syndrome children to normal people was 1.67 +/- 0.13 to 0.99 +/- 0.10, respectively (p < 0.001). Real-time PCR technique effectively differentiates the normal fetuses from the trisomy 21 syndrome fetuses; therefore, compared to the results of the conventional cytogenetic karyotype analysis, the DSCR3/GAPDH ratios of trisomy 21 syndrome fetuses are significantly higher than those of normal fetuses.
CONCLUSION: Because the DSCR3/GAPDH ratio of trisomy 21 syndrome fetuses is significantly higher than that of normal fetuses, the genomic DNA real-time PCR technique may be a reliable and specific method for the rapid prenatal diagnosis of Down syndrome. Copyright (c) 2004 John Wiley & Sons, Ltd.