Project description:Noninvasive prenatal diagnosis currently used does not achieve desirable levels of sensitivity and specificity. Recently, fetal methylated DNA biomarkers in maternal whole blood have been explored for noninvasive prenatal detection. However, such efforts cover only chromosomal aneuploidy; fetal methylated DNA biomarkers for detecting single-gene disease remain to be discovered. To address this issue, we systematically screened significantly hypermethylated genes in fetal tissues compared with maternal blood for noninvasive prenatal diagnosis of various inherited diseases. First, Methylated-CpG island recovery assay combined with CpG island array was performed in four maternal peripheral bloods and their corresponding placental tissues. Subsequently, direct bisulfite sequencing and combined bisulfite restriction analysis (COBRA) were carried out to validate the reliability of methylation microarray analysis. As results, 310 significantly hypermethylated genes in fetal tissues were detected by microarray. Two of five randomly selected hypermethylated genes detected by microarray were confirmed to be hypermethylated in fetal tissue samples by direct bisulfite sequencing. All four randomly selected hypermethylated genes detected by microarray were confirmed to be hypermethylated in five independent amniotic fluid samples and five independent chorionic villus samples from 10 pregnant women by CORBA. In conclusions, We found a lot of hypermethylated genes and methylation sites in fetal tissues, some of which have great potential to be developed into molecular markers for noninvasive prenatal diagnosis of monogenic disorders. Further clinical study is warranted to confirm these findings. Paired experiments, placental tissues vs. maternal peripheral bloods. Biological replicates: 4 placental tissues and 4 correspoding maternal peripheral bloods.
Project description:The discovery of fetal mRNA transcripts in maternal circulation holds great promise for noninvasive prenatal diagnosis. To identify potential fetal biomarkers, we studied whole blood and plasma transcripts common to term pregnant women and their newborns but reduced or absent in the postpartum mothers. In whole blood, 157 potentially-fetal transcripts were identified. RT-PCR confirmed the presence of specific transcripts, SNP analysis confirmed the presence of fetal transcripts in maternal circulation. Comparison of whole blood and plasma samples from the same women suggested that placental genes are more easily detected in plasma. We conclude that fetal and placental mRNA circulates in the blood of pregnant women.
Project description:Noninvasive prenatal diagnosis currently used does not achieve desirable levels of sensitivity and specificity. Recently, fetal methylated DNA biomarkers in maternal whole blood have been explored for noninvasive prenatal detection. However, such efforts cover only chromosomal aneuploidy; fetal methylated DNA biomarkers for detecting single-gene disease remain to be discovered. To address this issue, we systematically screened significantly hypermethylated genes in fetal tissues compared with maternal blood for noninvasive prenatal diagnosis of various inherited diseases. First, Methylated-CpG island recovery assay combined with CpG island array was performed in four maternal peripheral bloods and their corresponding placental tissues. Subsequently, direct bisulfite sequencing and combined bisulfite restriction analysis (COBRA) were carried out to validate the reliability of methylation microarray analysis. As results, 310 significantly hypermethylated genes in fetal tissues were detected by microarray. Two of five randomly selected hypermethylated genes detected by microarray were confirmed to be hypermethylated in fetal tissue samples by direct bisulfite sequencing. All four randomly selected hypermethylated genes detected by microarray were confirmed to be hypermethylated in five independent amniotic fluid samples and five independent chorionic villus samples from 10 pregnant women by CORBA. In conclusions, We found a lot of hypermethylated genes and methylation sites in fetal tissues, some of which have great potential to be developed into molecular markers for noninvasive prenatal diagnosis of monogenic disorders. Further clinical study is warranted to confirm these findings.
Project description:The discovery of fetal mRNA transcripts in maternal circulation holds great promise for noninvasive prenatal diagnosis. To identify potential fetal biomarkers, we studied whole blood and plasma transcripts common to term pregnant women and their newborns but reduced or absent in the postpartum mothers. In whole blood, 157 potentially-fetal transcripts were identified. RT-PCR confirmed the presence of specific transcripts, SNP analysis confirmed the presence of fetal transcripts in maternal circulation. Comparison of whole blood and plasma samples from the same women suggested that placental genes are more easily detected in plasma. We conclude that fetal and placental mRNA circulates in the blood of pregnant women. [I] We profiled whole antepartum (A), postpartum (P), and umbilical cord (U) blood samples from each of 9 mothers and their 10 newborns (1 set of twins, denoted as a and b after the sample names). [II] We also profiled plasma samples (A, P, and U) from three of those mothers to allow for a direct comparison between blood and plasma.
Project description:Genome wide DNA methylation profiling of normal and trisomic placentas, and maternal blood cell DNA. The aim of this study was to search for methylation differences between maternal and fetal(placenta) cell free DNA, and between normal and trisomic placentas for an optimized methylation based noninvasive prenatal diagnosis of fetal chromosomal aberations. The Illumina Infinium 450k Human DNA methylation Beadchip was used to obtain DNA methylation profiles across approximately 450,000 CpGs in DNA samples from Chorionic villus samples(CVS) and DNA samples from whole blood. Samples included 12 Maternal blood cell samples from normal pregnancies, 12 normal CVS, 12 Trisomy 21 CVS, 12 trisomy 18 CVS and 6 trisomy 13 CVS samples. Bisulphite converted DNA from the 54 samples were hybridized to the Illumina Infinium 450k Human Methylation Beadchip.
Project description:The uploaded results of two samples were SNParray results in our research of which fetal CNVs were detected by noninvasive prenatal test (NIPT) and confirmed by microarray results. Sample ZNY162 received prenatal diagnosis because at 17 gestational week the pregnant woman received NIPT showing 23Mb microdeletion in Chr18. Later ultrasound examination showed developmental anomalies of feet and the 13th ribs. The pregnant woman received amniocentesis and SNParray at the 21st gestational week, which confirmed the existence of the microdeletion in Chr18. DNA was extracted from 10ml amniotic fluid and tested by Affymetrix CytoScan HD array to detect CNVs in whole genome, showing arr 18q22.3q23(69,461,933-78,014,123) Ã1. Sample LMQ155 received prenatal diagnosis because of advanced maternal age and NIPT result of a 2.29Mb microduplication in Chr13 at 15 gestational week. Amniocentesis was performed at the 17th gestational week. Affymetrix CytoScan HD array were used to detect fetal CNVs in whole genome, which showed arr 13q21.2(60,399,612-61,730,194) Ã3 that was consistent with NIPT result.