Maternal and fetal genetic associations of PTGER3 and PON1 with preterm birth.

Objective: The purpose of this study was to identify associations between maternal and fetal genetic variants in candidate genes and spontaneous preterm birth (PTB) in a Norwegian population and to determine the effect size of those associations that corroborate a previous study of PTB.

Methods: DNA from 434 mother-baby dyads (214 cases and 220 controls) collected from the Norwegian Mother and Child Cohort (MoBa) was examined for association between 1,430 single nucleotide polymorphisms in 143 genes and PTB. These results were compared to a previous study on European Americans (EA) from Centennial Women's Hospital in Nashville, TN, USA.

Geographic ancestry and markers of preterm birth.

Several biomarkers associated with spontaneous preterm birth (PTB) have been discovered over the last decade. Many of these markers, such as cytokines, are associated with infection and inflammation. As such, these biomarkers represent biologically plausible candidates for assessing those at risk of PTB.

Variants in toll-like receptors 2 and 9 influence susceptibility to pulmonary tuberculosis in Caucasians, African-Americans, and West Africans.

Tuberculosis (TB) is a global public health problem and a source of preventable deaths each year, with 8.8 million new cases of TB and 1.6 million deaths worldwide in 2005.

NOS2A, TLR4, and IFNGR1 interactions influence pulmonary tuberculosis susceptibility in African-Americans.

Tuberculosis (TB) has substantial mortality worldwide with 5-10% of those exposed progressing to active TB disease. Studies in mice and humans indicate that the inducible nitric oxide synthase (iNOS) molecule plays an important role in immune response to TB. A mixed case-control association study of individuals with TB, relatives, or close contact controls was performed in 726 individuals (279 case and 166 control African-Americans; 198 case and 123 control Caucasians).

Racial disparity in pathophysiologic pathways of preterm birth based on genetic variants.

Objective: To study pathophysiologic pathways in spontaneous preterm birth and possibly the racial disparity associating with maternal and fetal genetic variations, using bioinformatics tools.

Methods: A large scale candidate gene association study was performed on 1442 SNPs in 130 genes in a case (preterm birth < 36 weeks) control study (term birth > 37 weeks). Both maternal and fetal DNA from Caucasians (172 cases and 198 controls) and 279 African-Americans (82 cases and 197 controls) were used.

CLCNKB-T481S and essential hypertension in a Ghanaian population.

Objective: Prior to the discovery of chloride channel Kb with a variant threonine change to serine at position 481 (CLCNKB-T481S) there were no variants or clinical disorders associated with gain-of-function defects in thick ascending limb of the kidney channels or transporters. CLCNKB-T481S is a novel gain-of-function variant that has been associated with essential hypertension. This finding has not been replicated until our current study.

Exploring the performance of Multifactor Dimensionality Reduction in large scale SNP studies and in the presence of genetic heterogeneity among epistatic disease models.

Background/aims: In genetic studies of complex disease a consideration for the investigator is detection of joint effects. The Multifactor Dimensionality Reduction (MDR) algorithm searches for these effects with an exhaustive approach. Previously unknown aspects of MDR performance were the power to detect interactive effects given large numbers of non-model loci or varying degrees of heterogeneity among multiple epistatic disease models.

Spontaneous preterm birth in African Americans is associated with infection and inflammatory response gene variants.

Objective: The objective of the study was to study the genetic risk factors of spontaneous preterm birth (PTB) in African Americans.

Study Design: Case-control analyses were performed using maternal and fetal deoxyribonucleic acid from 279 African American birth events (82 PTB and 197 term) and 1432 single-nucleotide polymorphisms from 130 candidate genes. Single-locus association and haplotype analyses were performed.

Preterm birth in Caucasians is associated with coagulation and inflammation pathway gene variants.

Spontaneous preterm birth (<37 weeks gestation-PTB) occurs in approximately 12% of pregnancies in the United States, and is the largest contributor to neonatal morbidity and mortality. PTB is a complex disease, potentially induced by several etiologic factors from multiple pathophysiologic pathways. To dissect the genetic risk factors of PTB a large-scale high-throughput candidate gene association study was performed examining 1536 SNP in 130 candidate genes from hypothesized PTB pathways.

Genetic regulation of amniotic fluid TNF-alpha and soluble TNF receptor concentrations affected by race and preterm birth.

Racial disparity in spontaneous preterm birth (PTB) between African Americans and Caucasians in the US is unexplained, but is probably related to differences in amniotic fluid (AF) inflammatory cytokine profiles. Therefore, this study analyzed the association of 34 single nucleotide polymorphisms (SNPs) in TNF-alpha and its receptor genes (TNFR1 and TNFR2) with AF TNF-alpha and soluble TNF receptor (R1 and R2) concentrations in PTB. Samples consisted of African American and Caucasian cases (PTB), and controls (term birth) for which both cytokine, and maternal and fetal genotype data were available.

Racial disparity in maternal-fetal genetic epistasis in spontaneous preterm birth.

Objective: To understand the differences in genetic interactions among tumor necrosis factor-alpha, interleukin-6 and their receptor gene variants between black and white patients in spontaneous preterm birth.

Study Design: Maternal and fetal DNA (n = 1195) were collected from cases (preterm birth < 36 weeks' gestation; n = 448), controls (> 37 weeks' gestation; n = 747), and genotyped for single nucleotide polymorphisms in tumor necrosis factor-alpha, tumor necrosis factor receptor 1, and tumor necrosis factor receptor 2, interleukin-6, and interleukin-6 receptor loci. Multifactor dimensionality reduction analysis was used to test all single and multilocus combinations for the ability to predict pregnancy outcome.

Patterns of cytokine profiles differ with pregnancy outcome and ethnicity.

Background: Preterm birth (PTB) is hypothesized to be an inflammatory response disease. However, no single factor alone is likely to explain PTB risk. It is more probable that coordinated networks of cytokines affect risk.

Interleukin-6 (IL-6) and receptor (IL6-R) gene haplotypes associate with amniotic fluid protein concentrations in preterm birth.

Spontaneous preterm birth (PTB-gestational age <37 weeks) occurs in approximately 450 000 births annually in the United States and is one of the leading causes of neonatal morbidity and mortality. Risk of PTB is affected by complex gene-environment interactions that are not well understood. We examined the PTB candidate gene, Interleukin 6 (IL-6) and its receptor (IL6-R) in both Caucasian (145 PTB and 194 term maternal; 140 PTB and 179 term fetal) and African-American (76 PTB and 191 term maternal; 66 PTB and 183 term fetal) DNA.

Mitochondrial DNA variant A4917G, smoking and spontaneous preterm birth.

Spontaneous preterm birth (PTB; <37 weeks gestation) is a major risk factor for neonatal morbidity and mortality. The exact cause of PTB is unknown but oxidative stress may play an important role. Genetic studies have recently begun to elucidate the role of genetic variation in PTB but these studies have overlooked the mitochondrial genome/gene(s) as a plausible PTB candidate.

Functional BSND variants in essential hypertension.

Background: Defects in the handling of renal salt reabsorption may contribute to interindividual differences in blood-pressure regulation and susceptibility to hypertension. Sodium chloride reabsorption in the thick ascending limb (TAL) is dependent in part on the chloride channel, ClC-Kb (encoded by CLCNKB), and its accessory subunit, barttin (encoded by BSND).

Methods: We investigated genetic variations in BSND in a screening population, and genotyped a homogenous cohort of normotensive and hypertensive Ghanaian subjects, in addition to four ethnically defined control populations.

Haplotype diversity in four genes (CLCNKA, CLCNKB, BSND, NEDD4L) involved in renal salt reabsorption.

Objective: Differences exist among various populations with regards to hypertension prevalence, severity, progression and response to therapy. Such differences may be due to genetic or environmental factors. We characterized the genetic variation and haplotype diversity of four hypertension candidate genes (CLCNKA, CLCNKB, BSND, NEDD4L) in four different ethnic groups (Caucasian Americans, African-Americans, Han Chinese, and Mexican-Americans).

A balanced accuracy function for epistasis modeling in imbalanced datasets using multifactor dimensionality reduction.

Multifactor dimensionality reduction (MDR) was developed as a method for detecting statistical patterns of epistasis. The overall goal of MDR is to change the representation space of the data to make interactions easier to detect. It is well known that machine learning methods may not provide robust models when the class variable (e.

Angiotensinogen promoter sequence variants in essential hypertension.

Background: Essential hypertension is a complex multifactorial disease caused by ill-defined genetic factors. The angiotensinogen (AGT) gene has been implicated as a risk factor in essential hypertension.

Methods: To assess the role of AGT in hypertension, we evaluated two polymorphisms (A-6G and C-20A) in the 5' region of the gene that have been shown to have a role in transcriptional regulation.

Data simulation software for whole-genome association and other studies in human genetics.

Genome-wide association studies have become a reality in the study of the genetics of complex disease. This technology provides a wealth of genomic information on patient samples, from which we hope to learn novel biology and detect important genetic and environmental factors for disease processes. Because strategies for analyzing these data have not kept pace with the laboratory methods that generate the data it is unlikely that these advances will immediately lead to an improved understanding of the genetic contribution to common human disease and drug response.

Ethnic differences in key candidate genes for spontaneous preterm birth: TNF-alpha and its receptors.

Objectives: Spontaneous preterm birth (PTB) has a significant ethnic disparity with people of African descent having an almost 2-fold higher incidence than those of European descent in the United States. This disparity may be caused by differences in the distribution of genetic risk factors. The objective of this study is to examine genetic differences between African-Americans and European Americans for single nucleotide polymorphisms (SNPs) in candidate genes for PTB.

Multilocus interactions at maternal tumor necrosis factor-alpha, tumor necrosis factor receptors, interleukin-6 and interleukin-6 receptor genes predict spontaneous preterm labor in European-American women.

Objective: We hypothesize that genetic variations (single nucleotide polymorphisms-SNPs) in the tumor necrosis factor-alpha (TNF-alpha), TNF receptors (TNFRI and TNFRII), interleukin-6 (IL-6) and IL-6 receptor (IL-6R) genes predict high-risk status for spontaneous preterm birth (sPTB) in European-American women. In this study we examine the allelic and genotypic variations and the gene-gene interactions in the TNF-alpha, TNFRs, IL-6, and IL-6R genes in maternal DNA samples by using a case-control model.

Study Design: Maternal DNA from cases of sPTB after preterm labor (n = 101) and controls (normal term labor and delivery) (n = 321) were genotyped for SNPs in the TNF-alpha (6), TNFRI (6), TNFRII (7), IL-6 (5), and IL-6R (3) loci.