Joint Effect Of Plasma C21orf105 And Plac4 On Diagnosing Fetal Trisomy 21

This study is proposed to investigate whether the expressions of C21orf105 and PLAC4 could identify trisomy 21 fetus during pregnancy. 38 females with fetal trisomy 21 and 40 healthy controls were admitted in the second-trimester between November 2011 and November 2013. Trisomy 21 was diagnosed based on the karyotype. We conducted RT-PCR with different storage time and temperature in order to evaluate their effects on blood sample stability in vitro. RT-PCR and western blot were conducted to evaluate the expressions of C21orf105 and PLAC4. In addition, ROC curve was generated to estimate the sensitivity and specificity of C21orf105, PLAC4 and their combination. There were no significant differences in age, height, weight, BMI index, weeks at blood-taking, nulliparous and family history of trisomy 21 between the case and control group (all P > 0.05). The expression levels of both C21orf105 and PLAC4 are up-regulated in trisomy 21 pregnancies compared to the control group (all P < 0.05). Importantly, AUC of C21orf105, PLAC4 and their combination were 0.77 (95% CI: 0.65-0.88), 0.90 (95% CI: 0.82-0.97) and 0.93 (95% CI: 0.86-0.99), respectively. The combination of C21orf105 and PLAC4 could be used for diagnosing fetal trisomy 21 during the second-trimester period of pregnancy.