Down syndrome is one of the major chromosomal anomalies in Korea. To decrease incidence of Down syndrome, antenatal diagnosis is essential. At present, antenatal diagnosis of Down syndrome is done by karyotyping from chorionic villus sampling,
aminocentesis, and cordocentsis. Al these methods have some problems such as a risk of abortion, a long waiting time, difficulties in sampling, and so on.
The aim of study was to confirm that PCR (Polymerase Chain Reaction) using D21S11 primers could be a diagnostic tool for Down syndrome. PCR using D21S11 primers with 32p labeling at 5' end was done in 21 cases of DNA from 21 Trisomy and 20 cases
of
DNA
from normal karyotype. PCR product was running for 10 hours on the 6% polyacrylamide gel under 1,000 V or for 8 hours under 1,500 V. After X-ray film exposure, it was read by densitometry.
Normal group showed 1:1 band or single band. 21 Trisomy group shoed 1.3-2:1 band or 2.3 times of density compared to normal single band or 3 bands. This method gave the result within 24 hours.
It can be an useful diagnostic tool to detect 21 Trisomy antenatally, especially in late pregnancy, and in preimplantation diagnosis.
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