Correlation of free fetal DNA with β-human chorionin gonadotropin in circulation in pregnant women with high-risk of Down's syndrome / 中华妇产科杂志

ABSTRACT

Objective To investigate significance and correlation of free fetal DNA (fDNA) and β-human chorionic gonadotropin(β-hCG) in circulation in pregnant women with high-risk of Down's syndrome (DS). Methods Pregnant women with a male fetus at second trimester screening for Down's syndrome were chosen, including 5 women with a trisomy 21 fetus (DS group), 21 women with DS high-risk pregnant women (DS high-risk group) matched with 22 normal pregnant women as control group. Free fDNA in maternal plasma were extracted. Male DYS14 gene was labled as fDNA, real-time PCR was used to detect fDNA expression. The concentration of β-hCG in maternal serum was detected by chemiluminescence immune assay. The relationship between level of free fDNA and β-hCG concentration was analyzed by Pearson correlation analysis. Results (1) The mean level of free fDNA was (127±58 ) GE/ml in DS group, which was significantly higher than (78±28) GE/ml in DS high-risk group and (48±21 ) GE/ml in control group,respectively (P<0.01). When compared the level of free fDNA between DS high-risk group and control group, it reached statistical difference (P<0.01). (2) The mean concentration of β-hCG was (97±43) kU/L in DS group, which was significantly higher than (58±25) kU/L in DS high-risk group and (38±19) kU/L in control group, respectively (P<0.01). The level of β-hCG in DS high-risk group was also significantly higher than control group (P<0.01). (3) The positive relationship between the level of free fDNA in maternal plasma and β-hCG concentration in maternal serum was observed amongthree groups (r=0.83,P<0.05;r=0.76,P<0.01;r=0.86,P<0.01). Conclusions Free fDNA in maternal plasma might be a candidate marker used for prenatal DS screening. However, its clinical value need to be evaluated because of positive correlation between free fDNA and β-HCG in maternal circulation.