Banzola Irina, Rusterholz Corinne, Zannoni Letizia, Rizzo Nicola, Zhong Xiao Yan, Caramelli Elisabetta, Holzgreve Wolfgang, Farina Antonio, Hahn Sinuhe
Laboratory for Prenatal Medicine and Gyn. Oncology, Department of Biomedicine and University Hospital, Basel, Switzerland.
Prenat Diagn. 2008 Dec;28(13):1262-7. doi: 10.1002/pd.2163.
Beta-human chorionic gonadotropin (HCG) and pregnancy-associated plasma protein (PAPP-A) are placentally produced proteins whose levels are altered in pregnancies with trisomy 21. PLAC4 is located on chromosome 21 and its expression is restricted to the placenta. Here we investigated whether the levels of beta-HCG-, PAPP-A- and PLAC4 mRNA could be able to discriminate pregnancies whose fetus is affected by trisomy 21.
Hundred and forty-three blood samples from normal pregnancies and eight samples from trisomic pregnancies were collected. Total RNA was extracted from whole maternal blood, reverse-transcribed and the three mRNAs were quantified by real-time quantitative PCR. Hundred and nine controls were also tested for the serum levels of PAPP-A and HCG proteins.
Beta-HCG and PLAC4 mRNAs were detected in all samples, in higher amounts than in plasma, whereas the detection rate for PAPP-A mRNA was below 10%. The levels of beta-HCG mRNA significantly correlated with the circulatory concentrations of the HCG protein. However, neither beta-HCG- nor PLAC4 mRNAs show a significant difference between cases and controls.
Maternal blood levels of beta-HCG-, PLAC4- and PAPP-A mRNAs are not useful markers for the screening of pregnancies with trisomy 21 as their concentrations are either not significantly altered (beta-HCG and PLAC4) or too low to be detected (PAPP-A).
β-人绒毛膜促性腺激素（HCG）和妊娠相关血浆蛋白（PAPP-A）是胎盘产生的蛋白质，其水平在21三体妊娠中会发生改变。PLAC4位于21号染色体上，其表达仅限于胎盘。在此，我们研究了β-HCG、PAPP-A和PLAC4 mRNA水平是否能够区分胎儿受21三体影响的妊娠。
收集了143份正常妊娠的血样和8份三体妊娠的血样。从全血中提取总RNA，进行逆转录，并通过实时定量PCR对三种mRNA进行定量。还对109名对照者的血清PAPP-A和HCG蛋白水平进行了检测。
在所有样本中均检测到β-HCG和PLAC4 mRNA，其含量高于血浆中的含量，而PAPP-A mRNA的检测率低于10%。β-HCG mRNA水平与HCG蛋白的循环浓度显著相关。然而，病例组和对照组之间β-HCG和PLAC4 mRNA均无显著差异。
母体血液中β-HCG、PLAC4和PAPP-A mRNA水平不是筛查21三体妊娠的有用标志物，因为它们的浓度要么没有显著改变（β-HCG和PLAC4），要么太低无法检测到（PAPP-A）。
