Alphatorquevirus is the most prevalent virus identified in blood from a matched maternal-infant preterm cohort.

OBJECTIVE: To determine the prevalence of virus in a previously uncharacterized matched maternal-infant preterm cohort and test if viral presence or viral load correlate with histologic chorioamnionitis, spontaneous preterm labor or pre-eclampsia. STUDY DESIGN: Using qRT-PCR/qPCR we tested plasma or whole blood samples from 56 matched maternal and premature infant dyads for: adenovirus, anellovirus (alphatorquevirus and betatorquevirus), cytomegalovirus (CMV), Epstein-Barr virus (EBV), enterovirus, human herpesvirus 6 (HHV6), parechovirus, and parvovirus B19. RESULT: Viral detection was more common in maternal samples 29/56 (52%) than in cord blood from their infants (4/56 (7%)) (p ≤ .0001). No significant difference in viral load or viral prevalence was identified between pregnancies with and without histologic chorioamnionitis, spontaneous preterm labor or pre-eclampsia. CONCLUSION: Despite frequent detection of virus in maternal samples, virus was less frequently detected in the infants. Additionally, there was no association of presence or quantity of virus in maternal blood with histologic chorioamnionitis, spontaneous preterm labor or pre-eclampsia in this small, but well-defined cohort. Future studies are necessary to further characterize the role of virus in placental inflammatory states and pregnancy outcomes.

Machine learning guided postnatal gestational age assessment using new-born screening metabolomic data in South Asia and sub-Saharan Africa.

BACKGROUND: Babies born early and/or small for gestational age in Low and Middle-income countries (LMICs) contribute substantially to global neonatal and infant mortality. Tracking this metric is critical at a population level for informed policy, advocacy, resources allocation and program evaluation and at an individual level for targeted care. Early prenatal ultrasound examination is not available in these settings, gestational age (GA) is estimated using new-born assessment, last menstrual period (LMP) recalls and birth weight, which are unreliable. Algorithms in developed settings, using metabolic screen data, provided GA estimates within 1-2 weeks of ultrasonography-based GA. We sought to leverage machine learning algorithms to improve accuracy and applicability of this approach to LMICs settings. METHODS: This study uses data from AMANHI-ACT, a prospective pregnancy cohorts in Asia and Africa where early pregnancy ultrasonography estimated GA and birth weight are available and metabolite screening data in a subset of 1318 new-borns were also available. We utilized this opportunity to develop machine learning (ML) algorithms. Random Forest Regressor was used where data was randomly split into model-building and model-testing dataset. Mean absolute error (MAE) and root mean square error (RMSE) were used to evaluate performance. Bootstrap procedures were used to estimate confidence intervals (CI) for RMSE and MAE. For pre-term birth identification ROC analysis with bootstrap and exact estimation of CI for area under curve (AUC) were performed. RESULTS: Overall model estimated GA had MAE of 5.2 days (95% CI 4.6-6.8), which was similar to performance in SGA, MAE 5.3 days (95% CI 4.6-6.2). GA was correctly estimated to within 1 week for 85.21% (95% CI 72.31-94.65). For preterm birth classification, AUC in ROC analysis was 98.1% (95% CI 96.0-99.0; p < 0.001). This model performed better than Iowa regression, AUC Difference 14.4% (95% CI 5-23.7; p = 0.002). CONCLUSIONS: Machine learning algorithms and models applied to metabolomic gestational age dating offer a ladder of opportunity for providing accurate population-level gestational age estimates in LMICs settings. These findings also point to an opportunity for investigation of region-specific models, more focused feasible analyte models, and broad untargeted metabolome investigation.

Using AMANHI-ACT cohorts for external validation of Iowa new-born metabolic profiles based models for postnatal gestational age estimation.

BACKGROUND: Globally, 15 million infants are born preterm and another 23.2 million infants are born small for gestational age (SGA). Determining burden of preterm and SGA births, is essential for effective planning, modification of health policies and targeting interventions for reducing these outcomes for which accurate estimation of gestational age (GA) is crucial. Early pregnancy ultrasound measurements, last menstrual period and post-natal neonatal examinations have proven to be not feasible or inaccurate. Proposed algorithms for GA estimation in western populations, based on routine new-born screening, though promising, lack validation in developing country settings. We evaluated the hypothesis that models developed in USA, also predicted GA in cohorts of South Asia (575) and Sub-Saharan Africa (736) with same precision. METHODS: Dried heel prick blood spots collected 24-72 hours after birth from 1311 new-borns, were analysed for standard metabolic screen. Regression algorithm based, GA estimates were computed from metabolic data and compared to first trimester ultrasound validated, GA estimates (gold standard). RESULTS: Overall Algorithm (metabolites + birthweight) estimated GA to within an average deviation of 1.5 weeks. The estimated GA was within the gold standard estimate by 1 and 2 weeks for 70.5% and 90.1% new-borns respectively. Inclusion of birthweight in the metabolites model improved discriminatory ability of this method, and showed promise in identifying preterm births. Receiver operating characteristic (ROC) curve analysis estimated an area under curve of 0.86 (conservative bootstrap 95% confidence interval (CI) = 0.83 to 0.89); P < 0.001) and Youden Index of 0.58 (95% CI = 0.51 to 0.64) with a corresponding sensitivity of 80.7% and specificity of 77.6%. CONCLUSION: Metabolic gestational age dating offers a novel means for accurate population-level gestational age estimates in LMIC settings and help preterm birth surveillance initiatives. Further research should focus on use of machine learning and newer analytic methods broader than conventional metabolic screen analytes, enabling incorporation of region-specific analytes and cord blood metabolic profiles models predicting gestational age accurately.

Variants in the fetal genome near pro-inflammatory cytokine genes on 2q13 associate with gestational duration.

The duration of pregnancy is influenced by fetal and maternal genetic and non-genetic factors. Here we report a fetal genome-wide association meta-analysis of gestational duration, and early preterm, preterm, and postterm birth in 84,689 infants. One locus on chromosome 2q13 is associated with gestational duration; the association is replicated in 9,291 additional infants (combined P = 3.96 × 10-14). Analysis of 15,588 mother-child pairs shows that the association is driven by fetal rather than maternal genotype. Functional experiments show that the lead SNP, rs7594852, alters the binding of the HIC1 transcriptional repressor. Genes at the locus include several interleukin 1 family members with roles in pro-inflammatory pathways that are central to the process of parturition. Further understanding of the underlying mechanisms will be of great public health importance, since giving birth either before or after the window of term gestation is associated with increased morbidity and mortality.

The Association of Polymorphisms in Circadian Clock and Lipid Metabolism Genes With 2nd Trimester Lipid Levels and Preterm Birth.

Deregulation of the circadian system in humans and animals can lead to various adverse reproductive outcomes due to genetic mutations and environmental factors. In addition to the clock, lipid metabolism may also play an important role in influencing reproductive outcomes. Despite the importance of the circadian clock and lipid metabolism in regulating birth timing few studies have examined the relationship between circadian genetics with lipid levels during pregnancy and their relationship with preterm birth (PTB). In this study we aimed to determine if single nucleotide polymorphisms (SNPs) in genes from the circadian clock and lipid metabolism influence 2nd trimester maternal lipid levels and if this is associated with an increased risk for PTB. We genotyped 72 SNPs across 40 genes previously associated with various metabolic abnormalities on 930 women with 2nd trimester serum lipid measurements. SNPs were analyzed for their relationship to levels of total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL) and triglycerides (TG) using linear regression. SNPs were also evaluated for their relationship to PTB using logistic regression. Five SNPs in four genes met statistical significance after Bonferroni correction (p < 1.8 × 10-4) with one or more lipid levels. Of these, four SNPs were in lipid related metabolism genes: rs7412 in APOE with total cholesterol, HDL and LDL, rs646776 and rs599839 in CELSR2-PSRC1-SORT1 gene cluster with total cholesterol, HDL and LDL and rs738409 in PNPLA3 with HDL and TG and one was in a circadian clock gene: rs228669 in PER3 with TG. Of these SNPs only PER3 rs228669 was marginally associated with PTB (p = 0.02). In addition, PER3 rs228669 acts as an effect modifier on the relationship between TG and PTB.

Correction: Whole exome sequencing reveals HSPA1L as a genetic risk factor for spontaneous preterm birth.

[This corrects the article DOI: 10.1371/journal.pgen.1007394.].

Whole exome sequencing reveals HSPA1L as a genetic risk factor for spontaneous preterm birth.

Preterm birth is a leading cause of morbidity and mortality in infants. Genetic and environmental factors play a role in the susceptibility to preterm birth, but despite many investigations, the genetic basis for preterm birth remain largely unknown. Our objective was to identify rare, possibly damaging, nucleotide variants in mothers from families with recurrent spontaneous preterm births (SPTB). DNA samples from 17 Finnish mothers who delivered at least one infant preterm were subjected to whole exome sequencing. All mothers were of northern Finnish origin and were from seven multiplex families. Additional replication samples of European origin consisted of 93 Danish sister pairs (and two sister triads), all with a history of a preterm delivery. Rare exonic variants (frequency <1%) were analyzed to identify genes and pathways likely to affect SPTB susceptibility. We identified rare, possibly damaging, variants in genes that were common to multiple affected individuals. The glucocorticoid receptor signaling pathway was the most significant (p<1.7e-8) with genes containing these variants in a subgroup of ten Finnish mothers, each having had 2-4 SPTBs. This pathway was replicated among the Danish sister pairs. A gene in this pathway, heat shock protein family A (Hsp70) member 1 like (HSPA1L), contains two likely damaging missense alleles that were found in four different Finnish families. One of the variants (rs34620296) had a higher frequency in cases compared to controls (0.0025 vs. 0.0010, p = 0.002) in a large preterm birth genome-wide association study (GWAS) consisting of mothers of general European ancestry. Sister pairs in replication samples also shared rare, likely damaging HSPA1L variants. Furthermore, in silico analysis predicted an additional phosphorylation site generated by rs34620296 that could potentially affect chaperone activity or HSPA1L protein stability. Finally, in vitro functional experiment showed a link between HSPA1L activity and decidualization. In conclusion, rare, likely damaging, variants in HSPA1L were observed in multiple families with recurrent SPTB.

Correction: Prediction of preterm birth with and without preeclampsia using mid-pregnancy immune and growth-related molecular factors and maternal characteristics.

This Article was originally published under Nature Research's License to Publish, but has nowbeen made available under a [CC BY 4.0] license. The PDF and HTML versions of the Articlehave been modified accordingly.

Mutations in the Epithelial Cadherin-p120-Catenin Complex Cause Mendelian Non-Syndromic Cleft Lip with or without Cleft Palate.

Non-syndromic cleft lip with or without cleft palate (NS-CL/P) is one of the most common human birth defects and is generally considered a complex trait. Despite numerous loci identified by genome-wide association studies, the effect sizes of common variants are relatively small, with much of the presumed genetic contribution remaining elusive. We report exome-sequencing results in 209 people from 72 multi-affected families with pedigree structures consistent with autosomal-dominant inheritance and variable penetrance. Herein, pathogenic variants are described in four genes encoding components of the p120-catenin complex (CTNND1, PLEKHA7, PLEKHA5) and an epithelial splicing regulator (ESRP2), in addition to the known CL/P-associated gene, CDH1, which encodes E-cadherin. The findings were also validated in a second cohort of 497 people with NS-CL/P, comprising small families and singletons with pathogenic variants in these genes identified in 14% of multi-affected families and 2% of the replication cohort of smaller families. Enriched expression of each gene/protein in human and mouse embryonic oro-palatal epithelia, demonstration of functional impact of CTNND1 and ESRP2 variants, and recapitulation of the CL/P spectrum in Ctnnd1 knockout mice support a causative role in CL/P pathogenesis. These data show that primary defects in regulators of epithelial cell adhesion are the most significant contributors to NS-CL/P identified to date and that inherited and de novo single gene variants explain a substantial proportion of NS-CL/P.

Prediction of preterm birth with and without preeclampsia using mid-pregnancy immune and growth-related molecular factors and maternal characteristics.

OBJECTIVE: To evaluate if mid-pregnancy immune and growth-related molecular factors predict preterm birth (PTB) with and without (±) preeclampsia. STUDY DESIGN: Included were 400 women with singleton deliveries in California in 2009-2010 (200 PTB and 200 term) divided into training and testing samples at a 2:1 ratio. Sixty-three markers were tested in 15-20 serum samples using multiplex technology. Linear discriminate analysis was used to create a discriminate function. Model performance was assessed using area under the receiver operating characteristic curve (AUC). RESULTS: Twenty-five serum biomarkers along with maternal age <34 years and poverty status identified >80% of women with PTB ± preeclampsia with best performance in women with preterm preeclampsia (AUC = 0.889, 95% confidence interval (0.822-0.959) training; 0.883 (0.804-0.963) testing). CONCLUSION: Together with maternal age and poverty status, mid-pregnancy immune and growth factors reliably identified most women who went on to have a PTB ± preeclampsia.

Genetic Associations with Gestational Duration and Spontaneous Preterm Birth.

BACKGROUND: Despite evidence that genetic factors contribute to the duration of gestation and the risk of preterm birth, robust associations with genetic variants have not been identified. We used large data sets that included the gestational duration to determine possible genetic associations. METHODS: We performed a genomewide association study in a discovery set of samples obtained from 43,568 women of European ancestry using gestational duration as a continuous trait and term or preterm (<37 weeks) birth as a dichotomous outcome. We used samples from three Nordic data sets (involving a total of 8643 women) to test for replication of genomic loci that had significant genomewide association (P<5.0×10-8) or an association with suggestive significance (P<1.0×10-6) in the discovery set. RESULTS: In the discovery and replication data sets, four loci (EBF1, EEFSEC, AGTR2, and WNT4) were significantly associated with gestational duration. Functional analysis showed that an implicated variant in WNT4 alters the binding of the estrogen receptor. The association between variants in ADCY5 and RAP2C and gestational duration had suggestive significance in the discovery set and significant evidence of association in the replication sets; these variants also showed genomewide significance in a joint analysis. Common variants in EBF1, EEFSEC, and AGTR2 showed association with preterm birth with genomewide significance. An analysis of mother-infant dyads suggested that these variants act at the level of the maternal genome. CONCLUSIONS: In this genomewide association study, we found that variants at the EBF1, EEFSEC, AGTR2, WNT4, ADCY5, and RAP2C loci were associated with gestational duration and variants at the EBF1, EEFSEC, and AGTR2 loci with preterm birth. Previously established roles of these genes in uterine development, maternal nutrition, and vascular control support their mechanistic involvement. (Funded by the March of Dimes and others.).

Pregnancy-Related Changes of Amino Acid and Acylcarnitine Concentrations: The Impact of Obesity.

Objective Our primary objective was to assess the difference in amino and fatty acid biomarkers throughout pregnancy in women with and without obesity. Interactions between biomarkers and obesity status for associations with maternal and fetal metabolic measures were secondarily analyzed. Methods Overall 39 women (15 cases, 24 controls) were enrolled in this study during their 15- to 20-weeks' visit at the University of Iowa Hospitals and Clinics. We analyzed 32 amino acid and acylcarnitine concentrations with tandem mass spectrometry for differences throughout pregnancy as well as among women with and without obesity (body mass index [BMI] ≥ 35, BMI < 25). Results There were substantial changes in amino acids and acylcarnitine metabolites between the second and third trimesters (nonfasting state) of pregnancy that were significant after correcting for multiple testing (p < 0.002). Examining differences by maternal obesity, C8:1 (second trimester) and C2, C4-OH, C18:1 (third trimester) were higher in women with obesity compared with women without obesity. Several metabolites were marginally (0.002 < p < 0.05) correlated with birth weight, maternal glucose, and maternal weight gain stratified by obesity status and trimester. Conclusions Understanding maternal metabolism throughout pregnancy and the influence of obesity is a critical step in identifying potential mechanisms that may contribute to adverse outcomes in pregnancies complicated by obesity.

Combined elevated midpregnancy tumor necrosis factor alpha and hyperlipidemia in pregnancies resulting in early preterm birth.

OBJECTIVE: The objective of the study was to determine whether pregnancies resulting in early preterm birth (PTB) (<30 weeks) were more likely than term pregnancies to have elevated midtrimester serum tumor necrosis factor alpha (TNF-α) levels combined with lipid patterns suggestive of hyperlipidemia. STUDY DESIGN: In 2 nested case-control samples drawn from California and Iowa cohorts, we examined the frequency of elevated midpregnancy serum TNF-α levels (in the fourth quartile [4Q]) and lipid patterns suggestive of hyperlipidemia (eg, total cholesterol, low-density-lipoproteins, or triglycerides in the 4Q, high-density lipoproteins in the first quartile) (considered independently and by co-occurrence) in pregnancies resulting in early PTB compared with those resulting in term birth (n = 108 in California and n = 734 in Iowa). Odds ratios (ORs) and 95% confidence intervals (CIs) estimated in logistic regression models were used for comparisons. RESULTS: Early preterm pregnancies were 2-4 times more likely than term pregnancies to have a TNF-α level in the 4Q co-occurring with indicators of hyperlipidemia (37.5% vs 13.9% in the California sample (adjusted OR, 4.0; 95% CI, 1.1-16.3) and 26.3% vs 14.9% in the Iowa sample (adjusted OR, 2.7; 95% CI, 1.1-6.3). No differences between early preterm and term pregnancies were observed when TNF-α or target lipid abnormalities occurred in isolation. Observed differences were not explicable to any maternal or infant characteristics. CONCLUSION: Pregnancies resulting in early PTB were more likely than term pregnancies to have elevated midpregnancy TNF-α levels in combination with lipid patterns suggestive of hyperlipidemia.

Plasma lipids, genetic variants near APOA1, and the risk of infantile hypertrophic pyloric stenosis.

IMPORTANCE: Infantile hypertrophic pyloric stenosis (IHPS) is a serious condition in which hypertrophy of the pyloric sphincter muscle layer leads to gastric outlet obstruction. Infantile hypertrophic pyloric stenosis shows strong familial aggregation and heritability, but knowledge about specific genetic risk variants is limited. OBJECTIVES: To search the genome comprehensively for genetic associations with IHPS and validate findings in 3 independent sample sets. DESIGN, SETTING, AND PARTICIPANTS: During stage 1, we used reference data from the 1000 Genomes Project for imputation into a genome-wide data set of 1001 Danish surgery-confirmed samples (cases diagnosed 1987-2008) and 2371 disease-free controls. In stage 2, the 5 most significantly associated loci were tested in independent case-control sample sets from Denmark (cases diagnosed 1983-2010), Sweden (cases diagnosed 1958-2011), and the United States (cases diagnosed 1998-2005), with a total of 1663 cases and 2315 controls. MAIN OUTCOMES AND MEASURES: Association of genetic variation with the presence of infantile hypertrophic pyloric stenosis. RESULTS: We found a new genome-wide significant locus for IHPS at chromosome 11q23.3. The single-nucleotide polymorphism (SNP) with the lowest P value at the locus, rs12721025 (odds ratio [OR], 1.59; 95% CI, 1.38-1.83; P = 1.9 × 10(-10)), is located 301 bases downstream of the apolipoprotein A-I (APOA1) gene and is correlated (r2 between 0.46 and 0.80) with SNPs previously found to be associated with levels of circulating cholesterol. For these SNPs, the cholesterol-lowering allele consistently was associated with increased risk of IHPS. CONCLUSIONS AND RELEVANCE: This study identified a new genome-wide significant locus for IHPS. Characteristics of this locus suggest the possibility of an inverse relationship between levels of circulating cholesterol in neonates and IHPS risk, which warrants further investigation.

A proposed method to predict preterm birth using clinical data, standard maternal serum screening, and cholesterol.

OBJECTIVE: The objective of the study was to create a predictive model for preterm birth (PTB) from available clinical data and serum analytes. STUDY DESIGN: Serum analytes and routine pregnancy screening plus cholesterol and corresponding health information were linked to birth certificate data for a cohort of 2699 Iowa women with serum sampled in the first and second trimester. Stepwise logistic regression was used to select the best predictive model for PTB. RESULTS: Serum screening markers remained significant predictors of PTB, even after controlling for maternal characteristics. The best predictive model included maternal characteristics, first-trimester total cholesterol, total cholesterol change between trimesters, and second-trimester alpha-fetoprotein and inhibin A. The model showed better discriminatory ability than PTB history alone and performed similarly in subgroups of women without past PTB. CONCLUSION: Using clinical and serum screening data, a potentially useful predictor of PTB was constructed. Validation and replication in other populations, and incorporation of other measures that identify PTB risk, like cervical length, can be a step toward identifying additional women who may benefit from new or currently available interventions.

Elevated procalcitonin and C-reactive protein as potential biomarkers of sepsis in a subpopulation of thrombotic microangiopathy patients.

Thrombotic microangiopathy (TMA) comprises a group of microvascular thrombosis syndromes associated with multiple pathogenic factors. Deficient activity of ADAMTS13 is a pathogenic factor in a subset of TMA patients that provides a strong rationale for plasma exchange treatment. However, the subset of TMA patients with normal ADAMTS13 activity remains a heterogeneous group of patients in which the appropriate treatment is not well understood. In addition to the common forms of TMA thrombotic thrombocytopenic purpura and the hemolytic uremic syndrome, the differential diagnosis of TMA may include sepsis, autoimmune disorders, and disseminated intravascular coagulation. Optimal treatment of TMA depends on timely recognition of treatable pathogenic factors. We hypothesized that sepsis is a rapidly identifiable pathogenic factor in a subset of TMA patients. To test this hypothesis, we retrospectively measured the rapid biomarkers of sepsis C-reactive protein (CRP) and procalcitonin (PCT), in a repository of pretreatment plasma samples from 61 TMA patients treated with plasma exchange. Levels were analyzed in 31 severely ADAMTS13-deficient and 30 ADAMTS13-normal patients. None of the 31 patients with severe deficiency of ADAMTS13 had elevated PCT. However, 11 of 30 (37%) non-ADAMTS13-deficient patient samples were strongly positive for PCT. These patient samples also had a >10-fold higher median CRP level than patients with normal PCT. We conclude that rapid assays may help identify sepsis in a subset of TMA patients.

Leukocyte proteases cleave von Willebrand factor at or near the ADAMTS13 cleavage site.

The function of von Willebrand factor (VWF) is regulated by proteolysis, which limits its multimeric size and ability to tether platelets. The importance of ADAMTS13 metalloprotease in VWF regulation is demonstrated by the association between severe deficiency of ADAMTS13 and thrombotic thrombocytopenic purpura (TTP). However, ADAMTS13 activity levels do not always correlate with the clinical course of TTP, suggesting that other proteases could be important in regulating VWF. We identified 4 leukocyte proteases that cleave the synthetic VWF substrate FRETS-VWF73 and multimeric VWF. Elastase and proteinase 3 (PR3) cleave multimeric VWF and FRETS-VWF73 at the V(1607)-T(1608) peptide bond; cathepsin G and matrix metalloprotease 9 cleave VWF substrates at the Y(1605)-M(1606) and M(1606)-V(1607) bonds, respectively. Isolated intact human neutrophils cleave FRETS-VWF73 at the V(1607)-T(1608) peptide bond, suggesting that elastase or PR3 expressed on leukocyte surfaces might cleave VWF. In the presence of normal or ADAMTS13-deficient plasma, cleavage of FRETS-VWF73 by resting neutrophils is abolished. However, activated neutrophils retain proteolytic activity toward FRETS-VWF73 in the presence of plasma. Although the in vivo relevance remains to be established, these studies suggest the existence of a "hot spot" of VWF proteolysis in the VWF A2 domain, and support the possibility that activated leukocytes may participate in the proteolytic regulation of VWF.

Role of elastin polymorphisms in panic disorder.

Panic disorder (PD) is a complex neuropsychiatric disorder that has been associated with an increased frequency of mitral valve prolapse. Elastin is a prominent component of mitral valves and, in a genome screen of 23 pedigrees with PD, we found evidence of linkage to the region of chromosome 7 that contains the elastin gene (ELN). Therefore, we examined the minimal essential promoter and coding regions of ELN in 23 independent probands from the families in our linkage studies using single strand conformational polymorphism analysis. We found three polymorphisms including one that coded for a non-conservative amino acid change. However, none of these polymorphisms were associated with panic disorder in a case-control analysis or linked to it in multiplex pedigrees. In our pedigrees, exonic polymorphisms in ELN do not play a major role in the genetic vulnerability to PD.