Project description:Preterm labor resulting in the delivery of a premature child is a complex problem with an enormous impact on individuals, families and society. An estimated 500,000 children are born prematurely in the U.S. each year, and 5 million worldwide die annually of prematurity and its complications. Prematurity is also the single largest contributor to disability-adjusted life years, a measure of the lifetime impact of a disease. Despite the importance of the problem and its disproportionate occurrence in poor and minority populations, its underlying etiology (or etiologies) remains unknown; the single best predictor for preterm delivery is a previous preterm birth. The largest single cause of prematurity is spontaneous preterm labor, and suspected triggers for this include infection, stress, poor nutrition and genetic factors. Family and twin studies provide strong evidence that genetic factors underlie about 40% of the risk for prematurity. A major challenge in studying genetic factors in prematurity is maternal/uterine factors, fetal/placental factors, or both may influence risk. Thus, any approach to studying preterm birth should account for both infant and maternal risk, environmental covariates and interactions. The Danish National Birth Cohort (DNBC) is a well-established, prospective cohort that enrolled women early in pregnancy, prior to any adverse pregnancy outcomes, to minimize bias in data collection and sampling. See details at: <a href="http://www.ssi.dk/English" target="_blank">http://www.ssi.dk/English</a>. The DNBC followed over 100,000 pregnancies beginning in the first trimester and has extensive biological material and epidemiologic data on health outcomes in both mother and child. The current study posted on dbGaP contains data from a genome-wide case/control study using approximately 1,000 preterm mother-child pairs from the DNBC most with spontaneous onset of labor or preterm premature rupture of membranes (PPROM), along with 1,000 control pairs where the child was born at ~40 weeks' gestation. After data cleaning some small changes in case/control status and other variables resulted in minor changes in numbers of cases or controls in certain categories. Environmental variables are being used as covariates in the analysis. To replicate positive findings, we are using additional mother-child pairs from the DNBC and from the general Danish population, as well as 2200 samples coming primarily from an African-American population known to have high rates of preterm labor and delivery. This group includes over 1000 mostly very low birthweight infants, over 500 infant term controls, 326 term mother/baby pairs and 180 preterm mother/baby pairs. The data from these additional cohorts will be available in separate dbGaP postings. The study is expected to yield a better understanding of the biology of parturition, identify common genetic factors that play a role in preterm birth and its complications and suggest environmental modifications that can prolong gestation, with the goal of improving both neonatal and adult outcomes. This study is part of the Gene Environment Association Studies initiative (GENEVA, <a href="http://www.genevastudy.org" target="_blank">http://www.genevastudy.org</a>) funded by the trans-NIH Genes, Environment, and Health Initiative (GEI). The overarching goal is to identify novel genetic factors that contribute to prematurity and its complications through large-scale genome-wide association studies of a well-characterized cohort of Danish mothers and babies. Genotyping was performed at the Johns Hopkins University Center for Inherited Disease Research (CIDR). Data cleaning and harmonization were done at the GEI-funded GENEVA Coordinating Center at the University of Washington.

Project description:Preterm delivery resulting in the birth of a premature infant is a complex problem with a devastating impact on individuals, families and society. The prevalence of preterm birth has increased steadily in developed countries over the last 20 years and more than three million children die of preterm birth worldwide each year. Despite the importance of the problem and its disproportionate occurrence in poor and minority populations, the underlying causes have been difficult to identify. Spontaneous preterm labor has as its suspected triggers infection, stress, poor nutrition and inherited factors. The single best predictor for preterm delivery is a previous preterm birth. Studies of twins and of recurrences within families provide evidence that genetic factors underlie a substantive component of the risk for prematurity. One major challenge in studying genetic factors in prematurity is that the risk case is not truly established. The genetic risk could reside either in the mother and her uterus or in the infant/placenta. Identification of genetic factors in the mother and/or infant could provide insights into identifying relevant environmental covariates that may be more amenable to rapid interventions but difficult to find using standard epidemiology alone. A comprehensive genome-wide association study (GWAS) is the ideal way to identify those genes that would not be suspected based on our current understanding of the biology of parturition. We are using 2200 African American samples with term or preterm labor. A subset of these (~800) are infant samples recruited by the Neonatal Research Network as part of a study on cytokines and infection in extremely low birth weight infants (Schelonka RL, et al., 2011. PMID: <a href="http://www.ncbi.nlm.nih.gov/pubmed/21145756" target="_blank">21145756</a>). Therefore, this group consists of infants <1,000 grams with clinical outcome data for the infant allowing study of the genetic contributors for not only preterm birth but also the complications that often accompany preterm birth. The result will enable a better understanding of the biology of parturition and suggest environmental modifications that can prolong gestations to improve neonatal and adult outcomes. This study is part of the Gene Environment Association Studies initiative (GENEVA, <a href="http://www.genevastudy.org" target="_blank">http://www.genevastudy.org</a>) funded by the trans-NIH Genes, Environment, and Health Initiative (GEI). The overarching goal is to identify novel genetic factors that contribute to preterm birth through large-scale genome-wide association studies of African-American cases and controls from multiple sites in the United States. Genotyping was performed at the Johns Hopkins University Center for Inherited Disease Research (CIDR). Data cleaning and harmonization were done at the GEI-funded GENEVA Coordinating Center at the University of Washington.

Project description:Preterm labor resulting in the delivery of a premature child is a complex problem with an enormous impact on individuals, families and society. An estimated 500,000 children are born prematurely in the U.S. each year, and 5 million worldwide die annually of prematurity and its complications. Prematurity is also the single largest contributor to disability-adjusted life years, a measure of the lifetime impact of a disease. Despite the importance of the problem and its disproportionate occurrence in poor and minority populations, its underlying etiology (or etiologies) remains unknown; the single best predictor for preterm delivery is a previous preterm birth. The largest single cause of prematurity is spontaneous preterm labor, and suspected triggers for this include infection, stress, poor nutrition and genetic factors. Family and twin studies provide strong evidence that genetic factors underlie about 40% of the risk for prematurity. A major challenge in studying genetic factors in prematurity is maternal/uterine factors, fetal/placental factors, or both may influence risk. Thus, any approach to studying preterm birth should account for both infant and maternal risk, environmental covariates and interactions. The Danish National Birth Cohort (DNBC) is a well-established, prospective cohort that enrolled women early in pregnancy, prior to any adverse pregnancy outcomes, to minimize bias in data collection and sampling. See details at: <a href="http://www.ssi.dk/English" target="_blank">http://www.ssi.dk/English</a>. The DNBC followed over 100,000 pregnancies beginning in the first trimester and has extensive biological material and epidemiologic data on health outcomes in both mother and child. The current study posted on dbGaP contains data from a genome-wide case/control study using approximately 1,000 preterm mother-child pairs from the DNBC most with spontaneous onset of labor or preterm premature rupture of membranes (PPROM), along with 1,000 control pairs where the child was born at ~40 weeks' gestation. After data cleaning some small changes in case/control status and other variables resulted in minor changes in numbers of cases or controls in certain categories. Environmental variables are being used as covariates in the analysis. To replicate positive findings, we are using additional mother-child pairs from the DNBC and from the general Danish population, as well as 2200 samples coming primarily from an African-American population known to have high rates of preterm labor and delivery. This group includes over 1000 mostly very low birthweight infants, over 500 infant term controls, 326 term mother/baby pairs and 180 preterm mother/baby pairs. The data from these additional cohorts will be available in separate dbGaP postings. The study is expected to yield a better understanding of the biology of parturition, identify common genetic factors that play a role in preterm birth and its complications and suggest environmental modifications that can prolong gestation, with the goal of improving both neonatal and adult outcomes. This study is part of the Gene Environment Association Studies initiative (GENEVA, <a href="http://www.genevastudy.org" target="_blank">http://www.genevastudy.org</a>) funded by the trans-NIH Genes, Environment, and Health Initiative (GEI). The overarching goal is to identify novel genetic factors that contribute to prematurity and its complications through large-scale genome-wide association studies of a well-characterized cohort of Danish mothers and babies. Genotyping was performed at the Johns Hopkins University Center for Inherited Disease Research (CIDR). Data cleaning and harmonization were done at the GEI-funded GENEVA Coordinating Center at the University of Washington.

Project description:Preterm birth is a main determinant of neonatal mortality and morbidity and a major contributor to the overall mortality and burden of disease. However, precise phenotyping of the preterm birth is hampered by the imprecise definition of the clinical phenotype and complexity of the molecular phenotype due to multiple pregnancy tissue types and molecular processes that may contribute to the preterm birth. The studyâ??s aim was to comprehensively evaluate the mRNA transcriptome that characterizes preterm and term labor using precisely phenotyped samples. Expression profiles of 73 genes and non-coding RNA sequences uniquely identified the four groups of patients: delivering preterm with (PL) and without labor (PNL), term with (TL) and without labor (TNL). The largest differences in gene expression among the four groups occurred in decidua, chorion and amnion. The gene expression profiles showed suppression of chemokines expression in TNL, withdrawal of this suppression in TL, activation of multiple pathways of inflammation in PL, and an immune rejection profile in PNL. The genes constituting expression signatures showed over-representation of three putative regulatory elements in their 5â?? and 3â??UTR regions. The results suggest that pregnancy is maintained by downregulation of chemokines at the maternal-fetal interface. Withdrawal of this downregulation results in the term birth and its overriding by the activation of multiple pathways of the immune system in the preterm birth. Complications of the pregnancy associated with impairment of placental function, which necessitated premature delivery of the fetus in the absence of labor, show gene expression patterns associated with immune rejection. 183 total RNA samples from 8 tissue types collected from 35 women grouped into six categories of pregnancy outcome. One microarray replicate per sample. Other Contributors: Radek Bukowski, Sam Parry and the NICHD Genomic and Proteomic Network for Preterm Birth Research

			Action	DRS
	GapExchange_phs000353.v1.p1.xml	Xml
	dbGaPEx2.1.5.xsd	Other
	phs000353.v1-Documents.zip	Other
	Study_Report.phs000353.GEI_PretermBirth_AA_Murray.v1.p1.MULTI.pdf	Pdf
	manifest_phs000353.GEI_PretermBirth_AA_Murray.v1.p1.c1.PTB.pdf	Pdf

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GENEVA Study of Preterm Delivery (African-American)

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