|Budget Amount *help
¥1,500,000 (Direct Cost : ¥1,500,000)
Fiscal Year 2000 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1999 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Peripheral blood samples were obtained from 61 pregnant women at 10-17 weeks of gestation before amniocentesis. DNA was extracted from 800 microL of each plasma or serum sample. To detect the Y-chromosome-specific sequences DYS14 and DYZ3 in the maternal plasma and serum, 40 cycles of PCR were carried out for each DNA extract. The PCR products were analyzed by 2.5% agarose gel electrophoresis and ethidium bromide staining, and the results were compared with the results of the cytogenetic analyses of amniocentesis.
Cytogenetic analysis of amniocentesis revealed that 31 pregnant women had a male fetus and the remaining 30 pregnant women had a female fetus. Both DYS14 and DYZ3 were detected in 27 of the 31 plasma samples obtained from pregnant women carrying a male fetus and in all of 31 serum samples obtained from the same women. Neither DYS14 nor DYZ3 was detected in either the plasma or serum samples obtained from any of the 30 pregnant women carrying a female fetus.
PCR analysis of mate
rnal serum can be used to diagnose fetal gender.
Serum samples were obtained from pregnant women at gestational ages ranging from 15 to 17 weeks, prior to their undergoing amniocentesis. In total, we examined 70 samples consisting of 55 cases of pregnancy with 46, XY, 5 cases with 47, XY, +21, 3 cases with 47, XY, +18, a single case with 46, XY, dup (1) and 2 cases with twins of 46, XY, and 4 cases with 46, XX which were used as negative controls. We measured the concentration of the SRY sequence as a molecular marker for fetal DNA using real-time quantitative polymerase chain reaction (PCR) assay.
The SRY sequence was detectable and measurable when the fetuses were male except for one case with 47, XY, +18. This case showed fetal growth retardation and bradycardia. No amplification signals of the SRY sequence were detected when the fetuses were female. The mean concentration of fetal DNA in maternal serum was 31.5 copies/ml in the pregnancy with 46, XY, 23.5 copies/ml in the pregnancies with 47, XY, +21 and 21.5 copies/ml in the pregnancies with 46, XY, +18. There were no significant differences in the concentration of fatal DNA between pregnancies with fetuses of normal karyotype and those with fetuses of abnormal karyotype. Less