Periconceptional nutrient intakes and risks of orofacial clefts in California

DNA methylation and its potential roles in common oral diseases

Oral diseases are among the most common diseases worldwide and are associated with systemic illnesses, and the rising occurrence of oral diseases significantly impacts the quality of life for many individuals. It is crucial to detect and treat these conditions early to prevent them from advancing. DNA methylation is a fundamental epigenetic process that contributes to a variety of diseases including various oral diseases. Taking advantage of its reversibility, DNA methylation becomes a viable therapeutic target by regulating various cellular processes. Understanding the potential role of this DNA alteration in oral diseases can provide significant advances and more opportunities for diagnosis and therapy. This article will review the biology of DNA methylation, and then mainly discuss the key findings on DNA methylation in oral cancer, periodontitis, endodontic disease, oral mucosal disease, and clefts of the lip and/or palate in the background of studies on global DNA methylation and gene-specific DNA methylation.

A Systematic Literature Review on the Association Between Toxic and Essential Trace Elements and the Risk of Orofacial Clefts in Infants

Orofacial clefts (OFCs) have been linked to various toxic and essential trace elements (TETEs) worldwide. However, review estimation is absent. Therefore, addressing the hypothesis that TETEs are associated with OFCs is the main area of this review. A systematic literature search was conducted using electronic databases through PubMed, Web of Science, Scopus, Science Direct, and Google Scholar between 2004 and August 2022. The "AND" and "OR" operators were used to make our search results inclusive and restrictive as follows: ("Toxic element*" OR "Heavy metal*") AND ("Toxic element*" OR "Lead OR Arsenic OR Mercury*")) AND ("Essential trace element*" OR "Zinc OR Selenium OR Copper*")) AND ("Orofacial cleft*" OR "Cleft lip*" OR "Cleft palate*") AND ("Infant*" OR "Newborn*" OR "Neonate*")). The presence of toxic elements was linked to the development of OFCs. The results showed that higher levels of toxic elements in various biological sample types were related to increased risks for OFCs. Increased concentrations of essential trace elements (ETEs) lowered the risk of OFCs. Maternal consumption of diets rich in ETEs, including zinc (Zn), selenium (Se), copper (Cu), cobalt (Co), and molybdenum (Mo), was linked to a more pronounced reduction in the risk of OFCs. Based on the findings, it is acceptable to infer that maternal exposure to toxic elements, whether through environmental contaminants or dietary sources, was associated with an elevated risk of OFCs. Furthermore, the study revealed that ETEs exhibited a potential protective role in reducing the incidence of OFCs. This observation highlights the importance of reducing exposure to toxic elements during pregnancy and suggests that optimizing maternal intake of ETEs could be an effective preventive strategy.

Scientific opinion on the tolerable upper intake level for preformed vitamin A and β-carotene

Following two requests from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the revision of the tolerable upper intake level (UL) for preformed vitamin A and β-carotene. Systematic reviews of the literature were conducted for priority adverse health effects of excess vitamin A intake, namely teratogenicity, hepatotoxicity and endpoints related to bone health. Available data did not allow to address whether β-carotene could potentiate preformed vitamin A toxicity. Teratogenicity was selected as the critical effect on which to base the UL for preformed vitamin A. The Panel proposes to retain the UL for preformed vitamin A of 3000 μg RE/day for adults. This UL applies to men and women, including women of child-bearing age, pregnant and lactating women and post-menopausal women. This value was scaled down to other population groups using allometric scaling (body weight0.75), leading to ULs between 600 μg RE/day (infants 4-11 months) and 2600 μg RE/day (adolescents 15-17 years). Based on available intake data, European populations are unlikely to exceed the UL for preformed vitamin A if consumption of liver, offal and products thereof is limited to once per month or less. Women who are planning to become pregnant or who are pregnant are advised not to consume liver products. Lung cancer risk was selected as the critical effect of excess supplemental β-carotene. The available data were not sufficient and suitable to characterise a dose-response relationship and identify a reference point; therefore, no UL could be established. There is no indication that β-carotene intake from the background diet is associated with adverse health effects. Smokers should avoid consuming food supplements containing β-carotene. The use of supplemental β-carotene by the general population should be limited to the purpose of meeting vitamin A requirements.

Contextualizing sociocultural beliefs about cleft, knowledge of the treatments, and factors associated with delay of treatment in Eastern Indonesia

INTRODUCTION

Indonesia is a multicultural Asian country with a high incidence of cleft. This study contextualizes how patients' sociocultural backgrounds hinder cleft management in a diverse nation.

MATERIAL AND METHODS

This study involved 202 families of cleft patients attending six tertiary care hospitals in South Sulawesi between 2021 and 2022. A mixed-methods, descriptive cross-sectional study employed semi-structured interviews and focus group discussions. Thematic content analysis was done using Murdock's causal attribution of illness. Knowledge of the treatments and surgery expectations used open coding. We held medical team focus group discussions to validate education on treatments. Cleft management education was thematically analyzed based on Indonesia's Minister of Health Decree.

RESULTS

Two hundred-two families and ten medical teams participated. Thematic content analysis revealed common beliefs and factors that hinder medical treatments. The participants were 109 Buginese, 57 Makassarese, 16 Durinese, 8 Luwunese, 8 Torajanese, and 4 Mandarese. 22.3 % were unaware of causation, while 29.2 % attributed it to natural causes. About half of the interviewees believed in supernatural attribution. Even though 40 % of participants knew little about the surgery, they agreed that surgery improves appearance and speech. Medical treatments are delayed due to a lack of treatment knowledge, parents' concerns about surgical safety, and beliefs about causes.

DISCUSSION

Indigenous societies in South Sulawesi believe in supernatural causes of cleft. Most had incomplete surgical treatment information. An intensive educational health program about causes, treatments, medical specialists, and treatment goals is warranted to enhance patient compliance with medical treatment, ultimately leading to improved health outcomes.

Disruption of DNA methylation-mediated cranial neural crest proliferation and differentiation causes orofacial clefts in mice

Orofacial clefts of the lip and palate are widely recognized to result from complex gene-environment interactions, but inadequate understanding of environmental risk factors has stymied development of prevention strategies. We interrogated the role of DNA methylation, an environmentally malleable epigenetic mechanism, in orofacial development. Expression of the key DNA methyltransferase enzyme DNMT1 was detected throughout palate morphogenesis in the epithelium and underlying cranial neural crest cell (cNCC) mesenchyme, a highly proliferative multipotent stem cell population that forms orofacial connective tissue. Genetic and pharmacologic manipulations of DNMT activity were then applied to define the tissue- and timing-dependent requirement of DNA methylation in orofacial development. cNCC-specific Dnmt1 inactivation targeting initial palate outgrowth resulted in OFCs, while later targeting during palatal shelf elevation and elongation did not. Conditional Dnmt1 deletion reduced cNCC proliferation and subsequent differentiation trajectory, resulting in attenuated outgrowth of the palatal shelves and altered development of cNCC-derived skeletal elements. Finally, we found that the cellular mechanisms of cleft pathogenesis observed in vivo can be recapitulated by pharmacologically reducing DNA methylation in multipotent cNCCs cultured in vitro. These findings demonstrate that DNA methylation is a crucial epigenetic regulator of cNCC biology, define a critical period of development in which its disruption directly causes OFCs, and provide opportunities to identify environmental influences that contribute to OFC risk.

Periconceptional use of vitamin A and the risk of giving birth to a child with nonsyndromic orofacial clefts-A meta-analysis

BACKGROUND

We conducted a meta-analysis of observational epidemiological studies to evaluate the association between periconceptional use of vitamin A and the risk of giving birth to a child with nonsyndromic orofacial clefts (NSOFCs).

METHODS

We carried out a systematic literature search of Embase, PubMed, Web of Science, Google Scholar, and OpenGrey from inception to June 30, 2021. Two reviewers independently evaluated the studies that met the inclusion criteria and filled out an abstraction form for each study. Study quality was assessed using the Newcastle-Ottawa Assessment Scale (NOS). Adjusted estimates were pooled with an inverse variance weighting using a random-effects model. Heterogeneity and publication bias were assessed using the Cochran's Q test and funnel plot, respectively.

RESULTS

A total of six case-control studies with moderate risk of bias were included. The pooled OR showed a 20% reduction in the risk of NSOFCs for periconceptional use of vitamin A which was not statistically significant (OR = .80; 95% CI .54-1.17, p = .25). For nonsyndromic cleft lip with or without cleft palate (NSCL/P), the studies were homogenous, and the pooled estimate showed a 13% risk reduction, which was significant (OR = .87; 95% CI .77-.99, p = .03). For nonsyndromic cleft palate only (NSCPO), the pooled estimate showed a 33% lower likelihood, which was not statistically significant (OR = .67; 95% CI .42-1.08, p = .10).

CONCLUSION

Our results suggest a possible protective effect for the periconceptional use of vitamin A on the risk of NSCL/P. This finding should be investigated further in prospective studies across multiple populations.

Environmental factors in non-syndromic orofacial clefts: A review based on meta-analyses results

Non-syndromic orofacial clefts (NSOFCs) are prevalent birth defects with a complex etiology where several interacting genetic and environmental factors have been observed. This narrative review describes maternal exposures that have been significantly associated with protective effects or risk factors. The statistically significant information reported here was found in meta-analysis studies, taking advantage of their precision in defining intervention effects and their management of heterogeneity between studies. In addition, I propose a hypothesis explaining the biological basis for the results of the meta-analyses. This review aims to improve the evidence available in parent counseling, to prevent the occurrence of orofacial clefts by suggesting lifestyle changes.

Effect of maternal dietary niacin intake on congenital anomalies: a systematic review and meta-analysis

PURPOSE

The significance of niacin in embryonic development has clinical implications in the counseling of pregnant women and may be used to inform nutrition recommendations. This study, therefore, aims to review the associations between maternal periconceptional niacin intake and congenital anomalies.

METHODS

A systematic search of Ovid MEDLINE, ClinicalTrials.gov, AMED, CENTRAL, Emcare, EMBASE, Maternity & Infant Care and Google Scholar was conducted between inception and 30 September 2020. Medical subject heading terms included "nicotinic acids" and related metabolites, "congenital anomalies" and specific types of congenital anomalies. Included studies reported the association between maternal niacin intake and congenital anomalies in their offspring and reported the measure of association. Studies involved solely the women with co-morbidities, animal, in vitro and qualitative studies were excluded. The risk of bias of included studies was assessed using the Newcastle-Ottawa Scale (NOS). A random effects-restricted maximum likelihood model was used to obtain summary estimates, and multivariable meta-regression model was used to adjust study-level covariates.

RESULTS

Of 21,908 retrieved citations, 14 case-control studies including 35,743 women met the inclusion criteria. Ten studies were conducted in the U.S, three in Netherlands and one in South Africa. The meta-analysis showed that expectant mothers with an insufficient niacin intake were significantly more likely to have babies with congenital abnormalities (odds ratio 1.13, 95% confidence interval 1.02-1.24) compared to mothers with adequate niacin intake. A similar association between niacin deficiency and congenital anomalies was observed (OR 1.15, 95% CI 1.03-1.26) when sensitivity analysis was conducted by quality of the included studies. Meta-regression showed neither statistically significant impact of study size (p = 0.859) nor time of niacin assessment (p = 0.127). The overall quality of evidence used is high-thirteen studies achieved a rating of six or seven stars out of a possible nine based on the NOS.

CONCLUSION

Inadequate maternal niacin intake is associated with an increased risk of congenital anomalies in the offspring. These findings may have implications in dietary counseling and use of niacin supplementation during pregnancy.

DNA Methylation Variation Is Identified in Monozygotic Twins Discordant for Non-syndromic Cleft Lip and Palate

Non-syndromic cleft lip with or without cleft palate (NSCLP) is the most common craniofacial birth defect. The etiology of NSCLP is complex with multiple genes and environmental factors playing causal roles. Although studies have identified numerous genetic markers associated with NSCLP, the role of epigenetic variation remains relatively unexplored. Because of their identical DNA sequences, monozygotic (MZ) twins discordant for NSCLP are an ideal model for examining the potential contribution of DNA methylation to non-syndromic orofacial clefting. In this study, we compared the patterns of whole genome DNA methylation in six MZ twin pairs discordant for NSCLP. Differentially methylated positions (DMPs) and regions (DMRs) were identified in NSCLP candidate genes, including differential methylation in MAFB and ZEB2 in two independent MZ twin pairs. In addition to DNA methylation differences in NSCLP candidate genes, we found common differential methylation in genes belonging to the Hippo signaling pathway, implicating this mechanosensory pathway in the etiology of NSCLP. The results of this novel approach using MZ twins discordant for NSCLP suggests that differential methylation is one mechanism contributing to NSCLP, meriting future studies on the role of DNA methylation in familial and sporadic NSCLP.

Maternal Vitamin B12 Status and Risk of Cleft Lip and Cleft Palate Birth Defects in Tamil Nadu State, India

BACKGROUND AND OBJECTIVE

The causal role of maternal nutrition in orofacial clefts is uncertain. We tested hypotheses that low maternal vitamin B₁₂ and low folate status are each associated with an increased risk of isolated cleft lip with or without cleft palate (CL±P) in a case-control study in Tamil Nadu state, India.

METHODS

Case-mothers of CL±P children (n = 47) and control-mothers of unaffected children (n = 50) were recruited an average of 1.4 years after birth of the index child and plasma vitamin B₁₂, methylmalonic acid (MMA), total homocysteine (tHcy), and folate were measured at that time. Logistic regression analyses estimated associations between nutrient biomarkers and case-control status.

RESULTS

Odds ratios (ORs) contrasting biomarker levels showed associations between case-mothers and low versus high plasma vitamin B₁₂ (OR = 2.48, 95% CI, 1.02-6.01) and high versus low plasma MMA, an indicator of poor B₁₂ status (OR = 3.65 95% CI, 1.21-11.05). Case-control status was not consistently associated with folate or tHcy levels. Low vitamin B₁₂ status, when defined by a combination of both plasma vitamin B₁₂ and MMA levels, had an even stronger association with case-mothers (OR = 6.54, 95% CI, 1.33-32.09).

CONCLUSIONS

Mothers of CL±P children in southern India were 6.5 times more likely to have poor vitamin B₁₂ status, defined by multiple biomarkers, compared to control-mothers. Further studies in populations with diverse nutritional backgrounds are required to determine whether poor maternal vitamin B₁₂ or folate levels or their interactions are causally related to CL±P.

Genetic variants in S-adenosyl-methionine synthesis pathway and nonsyndromic cleft lip with or without cleft palate in Chile

BACKGROUND

The S-adenosyl-methionine (SAM) availability is crucial for DNA methylation, an epigenetic mechanism involved in nonsyndromic cleft lip with or without cleft palate (NSCL/P) expression. The aim of this study was to assess the association between single-nucleotide polymorphisms (SNPs) of genes involved in SAM synthesis and NSCL/P in a Chilean population.

METHODS

In 234 cases and 309 controls, 18 SNPs in AHCY, MTR, MTRR, and MAT2A were genotyped, and the association between them and the phenotype was evaluated based on additive (allele), dominant, recessive and haplotype models, by odds ratio (OR) computing.

RESULTS

Three deep intronic SNPs of MTR showed a protective effect on NSCL/P expression: rs10925239 (OR 0.68; p = 0.0032; q = 0.0192), rs10925254 (OR 0.66; p = 0.0018; q = 0.0162), and rs3768142 (OR 0.66; p = 0.0015; q = 0.0162). Annotations in expression database demonstrate that the protective allele of the three SNPs is associated with a reduction of MTR expression summed to the prediction by bioinformatic tools of its potentiality to modify splicing sites.

CONCLUSIONS

The protective effect against NSCL/P of these intronic MTR SNPs seems to be related to a decrease in MTR enzyme expression, modulating the SAM availability for proper substrate methylation. However, functional analyses are necessary to confirm our findings.

IMPACT

SAM synthesis pathway genetic variants are factors associated to NSCL/P. This article adds new evidence for folate related genes in NSCL/P in Chile. Its impact is to contribute with potential new markers for genetic counseling.

Association between selected alkaline earth elements concentrations in umbilical cord and risk for cleft lip with or without cleft palate

The relationship between alkaline earth elements in utero exposure and the risk of cleft lip with or without cleft palate (CL ± P) remains unclear. We aimed to investigate the associations between the concentration of alkaline earth elements in umbilical cord and risk for CL ± P. A case-control study was carried out in this study, including 78 cases and 142 controls. Association between each metals and the risk of CL ± P were evaluated with conventional logistic regression, bayesian kernel machine regression and weighted quantile sum regression models. Logistic regression model indicated that in utero exposure to higher levels of Barium was associated with increasing risk for CL ± P (odds ratio = 2.79, 95% confidence interval, 1.22-6.38) and for cleft lip with cleft palate (odds ratio = 3.94, 95% confidence interval, 1.45-10.72). Bayesian kernel machine regression model showed the statistical association between the metals mixture and risk difference of CL ± P, and barium was associated with CL ± P risk when all other metals were held fixed at the 25th percentiles (risk difference = 1.07, 95% confidence interval, 1.01-1.14). In weighted quantile sum model, barium accounted for most of the weight index in the combined effect of the metals mixture. The weighted quantile sum index showed that a quartile increase in the index resulted in an increase odds of 1.69 (95% confidence interval, 1.16-2.46) for CL ± P and of 2.11 (95% confidence interval, 1.34-3.35) for CLP. No associations were found in the three statistical models between Calcium, Magnesium and Strontium and the risks of CL ± P. In conclusion, in utero exposure to mixtures of alkaline earth elements was associated with an increased risk for CL ± P, of which barium was likely to be important factors in the development.

Rare earth elements in umbilical cord and risk for orofacial clefts

Questions remain about the effects of rare earth elements (REEs) on reproductive health, and no study has explored in utero exposure to REEs and risk of orofacial clefts (OFCs). We recruited subjects from a case-control study conducted in Shanxi Province, China. Concentrations of fifteen REEs were quantified in umbilical cord samples by means of Inductively Coupled Plasma Mass Spectrometry measurements. We employed logistic regression and weighted quantile sum (WQS) regression models to estimate the association between REEs exposures and OFCs. Of 226 subjects included in our study, 34 were cleft lip only, 44 were cleft lip with cleft palate and 6 were cleft palate only. In the logistic regression model, concentrations above the median of all subjects were associated with an increased OFCs risk of 2.35-fold (95% CI: 1.22, 4.53) for Lanthanum and 2.12-fold for Neodymium (95% CI: 1.10, 4.10) adjusting for maternal age, BMI, gestational weeks, sex of infants and passive smoking. In WQS model, a quartile increase in the index resulting in an increase of 3.10 (95% CI: 1.38, 6.96) in the odds of OFC. Lanthanum and Neodymium were suggested to be important factors. The results were largely consistent for OFC subtypes. In conclusion, in utero exposure to mixtures of REEs increased the risk of OFCs. Lanthanum and Neodymium were likely to be important factors in the development of OFCs.

Folate intake, markers of folate status and oral clefts: An updated set of systematic reviews and meta-analyses

BACKGROUND

There has been a longstanding debate about the role of folate in the etiology of orofacial clefts (OFCs). Studies of different measures of nutritional intake or folate status have been done to investigate the possible role of folate in the prevention of OFC. Only one knowledge synthesis has attempted to bring together different types of evidence. The aim of the present work was to update it.

METHODS

Evidence for associations between OFC and dietary folate, supplement use, folic acid fortification, biomarkers of folate status, and variants of MTHFR (C677T and A1298C) were included. Potentially eligible articles were systematically identified from PubMed, Medline, Embase, and Web of Science (2007-2020) and combined using random-effects meta-analysis when appropriate. Quality assessments were conducted using the Newcastle-Ottawa scale and Cochrane's risk of bias tool.

RESULTS

Sixty-four studies published since the previous knowledge synthesis were identified, with eight of these identified through a supplementary search from October, 2018 to August, 2020. There was an inverse association between folic acid-containing supplement use before or during pregnancy and cleft lip with or without cleft palate (CL/P) (OR 0.60, 95% CI 0.51-0.69), with considerable between-study heterogeneity. The prevalence of CL/P showed a small decline post-folic acid fortification in seven studies (OR 0.94, 95% CI 0.86-1.02). No association was found between OFC and genetic markers of folate status. The coronavirus-19 pandemic has threatened food availability globally and therefore there is a need to maintain and even enhance surveillance concerning maternal intake of folate and related vitamins.

CONCLUSIONS

The risk of non-syndromic OFC was reduced among pregnant women with folic acid-containing supplements during the etiologically relevant period. However, high heterogeneity between included studies, incomplete reporting of population characteristics and variation in timing of exposure and supplement types mean that conclusions should be drawn with caution.

Maternal Folic Acid Intake and Risk of Nonsyndromic Orofacial Clefts: A Hospital-Based Case–Control Study in Bangalore, India

Background:

Orofacial clefts are the most common congenital anomaly worldwide. Cleft etiology appears to be multifactorial, with genetic and environmental components. Although periconceptional folic acid supplementation has been shown to be protective for neural tube defects, current evidence for its role in cleft prevention is mixed with few studies from low- and middle-income countries.

Aim:

To investigate the association between periconceptional folic acid intake and incidence of nonsyndromic orofacial clefts among infants in Bangalore, India.

Methods:

A hospital-based case–control study (106 cases, 212 controls) utilizing a questionnaire to collect data on prenatal supplements, dietary folate, and potentially confounding factors. Multivariate logistic regression analysis was used to assess relationships between folic acid supplementation and all nonsyndromic clefts, and in separate analyses for cleft lip and/or palate (CL/P) and cleft palate (CP), adjusting for statistically significant variables.

Results:

A statistically significant protective association was found for separate folic acid supplements (not combined with iron or multivitamins) taken in the periconceptional period and all clefts combined (adjusted odds ratio [OR]: 0.62, 95% confidence interval [CI], 0.45-0.86) and CL/P (adjusted OR: 0.57; 95% CI, 0.38-0.86). Higher levels of dietary folate were found to be associated with a reduced risk for all clefts (adjusted OR: 0.98, 95% CI, 0.96-0.99), CL/P (adjusted OR: 0.98, 95% CI, 0.96-0.99), and CP (adjusted OR: 0.96, 95% CI, 0.93-0.99).

Conclusion:

This study provides limited evidence for a protective association of periconceptional folic acid supplementation with nonsyndromic orofacial clefts. The low proportion of mothers taking folic acid supplements in the periconceptional period highlights the need for increased education and awareness regarding prenatal nutrition.

Epigenomic profiling of newborns with isolated orofacial clefts reveals widespread DNA methylation changes and implicates metastable epiallele regions in disease risk

Cleft lip with or without cleft palate (CL/P) is a common human birth defect whose etiologies remain largely unknown. Several studies have demonstrated that periconceptional supplementation of folic acid can reduce risk of CL/P in offspring. In this study, we tested the hypothesis that the preventive effect of folic acid is manifested through epigenetic modifications by determining whether DNA methylation changes are associated with CL/P. To more readily observe the potential effects of maternal folate on the offspring epigenome, we focused on births prior to mandatory dietary folate fortification in the United States (i.e. birth year 1997 or earlier). Genomic DNA methylation levels were assessed from archived newborn bloodspots in a 182-member case-control study using the Illumina® Human Beadchip 450K array. CL/P cases displayed striking epigenome-wide hypomethylation relative to controls: 63% of CpGs interrogated had lower methylation levels in case newborns, a trend which held up in racially stratified sub-groups. 28 CpG sites reached epigenome-wide significance and all were case-hypomethylated. The most significant CL/P-associated differentially methylated region encompassed the VTRNA2-1 gene, which was also hypomethylated in cases (FWER p = 0.014). This region has been previously characterized as a nutritionally-responsive, metastable epiallele and CL/P-associated methylation changes, in general, were greater at or near putative metastable epiallelic regions. Gene Set Enrichment Analysis of CL/P-associated DMRs showed an over-representation of genes involved in palate development such as WNT9B, MIR140 and LHX8. CL/P-associated DNA methylation changes may partly explain the mechanism by which orofacial clefts are responsive to maternal folate levels.

A discriminant analysis prediction model of non-syndromic cleft lip with or without cleft palate based on risk factors

BACKGROUND

A risk prediction model of non-syndromic cleft lip with or without cleft palate (NSCL/P) was established by a discriminant analysis to predict the individual risk of NSCL/P in pregnant women.

METHODS

A hospital-based case-control study was conducted with 113 cases of NSCL/P and 226 controls without NSCL/P. The cases and the controls were obtained from 52 birth defects' surveillance hospitals in Hunan Province, China. A questionnaire was administered in person to collect the variables relevant to NSCL/P by face to face interviews. Logistic regression models were used to analyze the influencing factors of NSCL/P, and a stepwise Fisher discriminant analysis was subsequently used to construct the prediction model.

RESULTS

In the univariate analysis, 13 influencing factors were related to NSCL/P, of which the following 8 influencing factors as predictors determined the discriminant prediction model: family income, maternal occupational hazards exposure, premarital medical examination, housing renovation, milk/soymilk intake in the first trimester of pregnancy, paternal occupational hazards exposure, paternal strong tea drinking, and family history of NSCL/P. The model had statistical significance (lambda = 0.772, chi-square = 86.044, df = 8, P < 0.001). Self-verification showed that 83.8 % of the participants were correctly predicted to be NSCL/P cases or controls with a sensitivity of 74.3 % and a specificity of 88.5 %. The area under the receiver operating characteristic curve (AUC) was 0.846.

CONCLUSIONS

The prediction model that was established using the risk factors of NSCL/P can be useful for predicting the risk of NSCL/P. Further research is needed to improve the model, and confirm the validity and reliability of the model.

Sequence variation in folate pathway genes and risks of human cleft lip with or without cleft palate

In an effort to comprehensively interrogate genetic variation in the folate pathway for risk of cleft lip with or without cleft palate (CLP), we evaluated 504 common and rare variants in 35 folate-related genes in a panel of 330 infants with CLP and 367 non-malformed controls. Odds ratios (OR) with 95% confidence intervals were computed for common genotypes. A Case-Control Difference metric was calculated for rare variants to highlight differentially occurring alleles. Interactions between variants and a maternal folate intake variable were also evaluated. In gene-only results, significant odds ratios were observed for multiple variants in the BHMT/BHMT2/DMGDH gene cluster, particularly in Hispanic infants. Also in this cluster, rare variant analysis highlighted a substantial case-control difference in BHMT rs60340837 (synonymous Y284Y). In Hispanics, the ALDH1L1 I812V variant (rs4646750) was the most significant risk allele: OR = 3.8 (95%CI = 1.6-9.2) when heterozygous. In non-Hispanic white infants, we observed significant risk for AHCYL2 rs1095423 (homozygous OR = 3.0, 95%CI 1.1-7.8) and the 68 bp CBS insertion (c.844ins68; heterozygous OR = 2.4, 95%CI = 1.1-5.3). Rare variant analysis in this group revealed case-control differences in MTRR and several other methionine cycle genes, a process implicated previously in clefting risk. In women with low folate intake specifically, increased risks were observed for CBS rs2851391 (OR = 3.6, 95%CI = 1.3-9.6) and the R259P nonsynonymous variant of TCN2 (rs1801198; OR = 2.8, 95%CI = 1.2-6.3). This comprehensive study provides further direction on candidate loci to help disentangle the folate-related developmental phenomena in human clefting risk. © 2016 Wiley Periodicals, Inc.

Genetic variation of FOXE1 and risk for orofacial clefts in a California population

We investigated whether orofacial clefts are associated with polymorphic variation within and around FOXE1. This California population-based case control study focused on white Hispanic and white nonHispanic infants among which there were 262 infants with cleft lip with or without cleft palate (CL/P), 103 with cleft palate only (CPO), and 382 unaffected controls. These cases and controls were genotyped for 13 SNPs across 220 Kb at the FOXE1 Locus. We observed associations with multiple FOXE1 SNPs for CL/P and for CPO, especially for the Hispanic study population. Increased risks were associated with the more common allele for all SNPs tested. Our results implicate FOXE1 as an important locus whose polymorphic variation increases risks for all types of isolated clefts, and opens a new biological pathway to investigate in efforts to understand genetic factors underlying human clefting. © 2016 Wiley Periodicals, Inc.

Validation of a Metallomics Analysis of Placenta Tissue by Inductively-Coupled Plasma Mass Spectrometry

Trace elements can play an important role in maternal health and fetal development, and deficiencies in some essential minerals including zinc and copper have been correlated in some individuals to the development of birth defects and adverse health outcomes later in life. The exact etiology of conditions like preeclampsia and the effects of fetal exposure to toxic metals has not been determined, making the assessment of trace element levels crucial to the elucidation of the causes of conditions like preeclampsia. Previous studies analyzing serum and placenta tissue have produced conflicting findings, suggesting the need for a robust, validated sample preparation and analysis method for the determination of trace elements in placenta. In this report, an acid digestion method and analysis by ICP-MS for a broad metallomics/mineralomics panel of trace elements is developed and validated over three experimental days for inter- and intraday precision and accuracy, linear range, matrix impact, and dilution verification. Spike recovery experiments were performed for the essential elements chromium (Cr), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), and zinc (Zn), and the toxic elements arsenic (As), cadmium (Cd), and lead (Pb) at levels equal to and in excess of native concentrations in control placenta tissue. The validated method will be essential for the development of scientific studies of maternal health and toxic metal exposure effects in childhood.