Uncertainty of fetal fraction determination in Non-Invasive Prenatal Screening by highly polymorphic SNPs.

Fetal fraction and the chromosome representation are the two key quantities used in Non-Invasive Prenatal Screening (NIPS) to determine the aneuploidy status of a fetus. Several methods for fetal fraction determination have been proposed in the literature, including a class of the methods, denoted snpFF, based on high-coverage targeted sequencing of highly polymorphic Single Nucleotide Polymorphisms (SNPs). The variant of snpFF, investigated here, has similar properties as the other variants of snpFF. We point out that the variability of the individual informative SNPs-based estimates of fetal fraction increases with the increase of fetal fraction. At 4% fetal fraction the Inter-Quartile Range (IQR) of the individual estimates of fetal fraction is around 3% and it increases to 6% at 15% fetal fraction. snpFF cannot detect fetal fraction below 2.5% because the number of informative SNPs becomes too small, even zero.

Association between 3'UTR polymorphisms in genes ACVR2A, AGTR1 and RGS2 and preeclampsia.

Preeclampsia (PE) is a pregnancy specific disease with several risk factors such as genetic polymorphisms, environmental and social factors participating in its development. The aim of this study was to investigate whether distribution of three putative regulatory SNPs rs13430086, rs5186, rs4606 in 3'UTR of genes ACVR2A, AGTR1 and RGS2, respectively, that have been associated with hypertension and regulation of trophoblast invasion differ between women with PE and control group. The associations of rs13430086, rs5186 and rs4606 with preeclampsia were tested in two groups - the group of 50 women with PE and the control group of 42 healthy pregnant women at term. DNA was isolated from blood samples and the determination of genotypes was performed using Real-Time PCR. Power analysis for the size of the cohort was performed and the results were analyzed using Fisher exact test. The AA genotype of ACVR2A rs13430086 was significantly associated with higher risk to preeclampsia compared with TT genotype (p = 0.026, OR: 5.39, 95%CI: 1.21-31.54). Results showed no association between genotypes and preeclampsia for polymorphisms rs5186, rs4606. Further studies are important in order to better understand the role of ACVR2A in the pathogenesis of PE.

Overexpression of miR-21 and miR-122 in preeclamptic placentas.

OBJECTIVE: Preeclampsia is a pregnancy-associated disease with the impact of genetic, epigenetic and environmental factors. Increased apoptosis was observed in cells from preeclamptic placentas. MicroRNAs are involved in the regulation of apoptosis and are abundant in placenta. In this study, we focused on the analysis of differential gene expression of apoptosis-associated miRNAs in preeclamptic placenta samples compared to the samples obtained from healthy pregnant women. METHODS: MicroRNA was extracted from placental samples of patients with preeclampsia and physiological course of the pregnancy. The gene expression of miR-155, miR-122 and miR-21 in placenta and control samples was estimated by relative quantitation (RQ) using TaqMan probes, normalized against RNU44. The RQ mean values were statistically evaluated by Man-Whitney test. RESULTS: Using the relative gene expression analysis, we could observe a significant increase in gene expression of miR-155 (p<0.001), miR-21 (p<0.0001) and miR-122 (p<0.01) in preeclamptic placentas. CONCLUSION: The apoptosis-associated miRNAs miR-21 and miR-122 are dysregulated in the term preeclamptic placentas. The increased miRNA expression suggest the downregulation of potential targets mRNAs, which can contribute to the pathogenesis of preeclampsia. The identification of their targets in placenta will improve our understanding of their role in preeclampsia.

mRNA expression in cervical specimens for determination of severe dysplasia or worse in HPV-16/18-positive squamous lesions.

OBJECTIVES: The objective of current study was to determine the p16 mRNA level in cervical cells by relative quantification (RQ) and to test viral E6 expression in human papillomavirus (HPV) -16 or -18-positive specimens by widely used methods. We targeted the pivotal mRNA level associated with severe dysplasia or worse. MATERIALS AND METHODS: Cervical specimens were taken from 134 women with cervical disease and 132 women with normal cytologic results. The presence of HPV was analyzed by sequencing. The results of p16 and E6 analyses were statistically processed in receiver operating characteristic curve analysis to predict severe dysplasia or worse. RESULTS: The HPV DNA was detected in 81.4% (109/134) of women with cervical disease and in 27.3% (36/132) of women with normal cytologic results. HPV-16 or -18 were present in 59.7% (80/134) of abnormal specimens. p16 and E6 mRNA expression was increasing with severity of cervical dysplasia. p16 mRNA expression was found 4.35-fold and 13.15-fold increased in high-grade squamous intraepithelial lesions and squamous cell carcinomas, respectively. E6 mRNA expression was significantly increased (p = .0038) in severe dysplasias or worse. The RQ method achieved better sensitivity (82.6%), and E6 mRNA got better specificity (80.6%) for the prediction of severe dysplasia or worse. CONCLUSIONS: An increasing level of p16 and E6 mRNA transcripts could mean the potential of cervical dysplasia progression to cancer, but further studies should be done to confirm this proposition. Nevertheless, we consider using both tests to improve the sensitivity and specificity for prediction of severe dysplasia or worse.

Association of specific diplotypes defined by common rs1800682 and rare rs34995925 single nucleotide polymorphisms within the STAT1 transcription binding site of the FAS gene promoter with preeclampsia.

The tolerance of fetal antigens by intradecidual T-cell involving the Fas-mediated apoptosis plays an important role in the physiological course of pregnancy. Objective of this study is to determine the association of diplotypes of common rs1800682G and rare rs34995925C alleles within the STAT1 transcription binding site of the FAS promoter region with preeclampsia. There were 116 preeclamptic women and 123 healthy control subjects from Hungary and Slovakia enrolled in the study. The presence of the GG or GA genotypes on rs1800682 was confirmed in 91 patients and 85 controls (OR = 1.628, 95%CI 0.907-2.92). The rare rs34995925 C allele laying 7 bp further from rs1800682 within STAT1 transcription binding site was detected in 3 preeclamptic cases and none healthy subjects. Haplotypes GT and AC were defined by common rs1800682G and rare rs34995925C alleles, respectively, and were considered as "low" FAS-producing. The combinations of GT or AC with normal FAS-producing haplotypes AT were considered as "low" FAS-producing diplotypes in dominant model. The "low" FAS -producing diplotype group of GT/GT, GT/AT, and AC/AT compared to the normal FAS-producing diplotype group of AT/AT showed OR = 1.91 (95%CI 1.04-3.48) and p = 0.03 for the association with preeclampsia.