The role of the folic acid to the prevention of orofacial cleft: an epidemiological study

Investigation of exposure to heavy metals (Hg, Pb, Cd, Co, and Cr) as the cause of congenital anomaly cases (orofacial cleft) in infants

Orofacial cleft (OFC) is one of the most common congenital defects, with worldwide cases occurring in approximately 1:700 to 1:1000 births. This incidence is among the highest birth defects in Indonesia, and the incidence rate in Bandung Regency (14.69%) is the second-highest in West Java province. The purpose of this study was to analyze the association of heavy metal factors that accumulate in infants to the risk of OFC in Bandung Regency. The method was used by testing heavy metals Hg, Pb, Cd, Co, and Cr in infant blood. The total sample were 54 samples, where the case respondent of 32 and 22 respondents as the control group. Blood samples were analyzed using ICP-MS Agilent 7900. The correlation using statistic analyze namely chi-square analysis (bivariate) and multiple logistic regression (multivariate). The results showed that there was a significant difference in the concentration of heavy metals Hg, Pb, and Cd as well as an increase in Pb and Cd in the infant's blood which was thought to be significantly associated with the risk of OFC.

Maternal periconceptional folic acid supplementation reduced risks of non-syndromic oral clefts in offspring

Maternal periconceptional folic acid supplementation (FAS) has been documented to be associated with decreased risk of nonsyndromic oral clefts (NsOC). However, the results remain inconclusive. In this population-based case–control study of 807 singletons affected by NsOC and 8070 healthy neonates who were born between October 2010 and September 2015 in Chengdu, China, we examined the association of maternal FAS with the risk of nonsyndromic cleft lip with or without cleft palate (NsCL/P), and cleft palate (NsCP). Unconditional logistic regression analysis was used to estimate the crude and adjusted odds ratios (ORs) and 95% confidential intervals (CI). Significant associations were found between maternal periconceptional FAS and decreased risk of NsCL/P (aOR = 0.41, 95% CI 0.33–0.51). This protective effect was also detected for NsCL (aOR = 0.42, 95% CI 0.30–0.58) and NsCLP (aOR = 0.41, 95% CI 0.31–0.54). Both maternal FAS started before and after the last menstrual period (LMP) were inversely associated with NsCL/P (before LMP, aOR = 0.43, 95% CI 0.33–0.56; after LMP, aOR = 0.41, 95% CI 0.33–0.51). The association between NsCP and maternal FAS initiating before LMP was also found (aOR = 0.52, 95% CI 0.30–0.90). The findings suggest that maternal periconceptional FAS can reduce the risk of each subtype of NsCL/P in offspring, while the potential effect on NsCP needs further investigations.

Gestational folate deficiency alters embryonic gene expression and cell function

Folic acid is a nutrient essential for embryonic development. Folate deficiency can cause embryonic lethality or neural tube defects and orofacial anomalies. Folate receptor 1 (Folr1) is a folate binding protein that facilitates the cellular uptake of dietary folate. To better understand the biological processes affected by folate deficiency, gene expression profiles of gestational day 9.5 (gd9.5) Folr1^-/- embryos were compared to those of gd9.5 Folr1^+/+ embryos. The expression of 837 genes/ESTs was found to be differentially altered in Folr1^-/- embryos, relative to those observed in wild-type embryos. The 837 differentially expressed genes were subjected to Ingenuity Pathway Analysis. Among the major biological functions affected in Folr1^-/- mice were those related to 'digestive system development/function', 'cardiovascular system development/function', 'tissue development', 'cellular development', and 'cell growth and differentiation', while the major canonical pathways affected were those associated with blood coagulation, embryonic stem cell transcription and cardiomyocyte differentiation (via BMP receptors). Cellular proliferation, apoptosis and migration were all significantly affected in the Folr1^-/- embryos. Cranial neural crest cells (NCCs) and neural tube explants, grown under folate-deficient conditions, exhibited marked reduction in directed migration that can be attributed, in part, to an altered cytoskeleton caused by perturbations in F-actin formation and/or assembly. The present study revealed that several developmentally relevant biological processes were compromised in Folr1^-/- embryos.

Environmental mechanisms of orofacial clefts

Orofacial clefts (OFCs) are among the most common birth defects and impart a significant burden on afflicted individuals and their families. It is increasingly understood that many nonsyndromic OFCs are a consequence of extrinsic factors, genetic susceptibilities, and interactions of the two. Therefore, understanding the environmental mechanisms of OFCs is important in the prevention of future cases. This review examines the molecular mechanisms associated with environmental factors that either protect against or increase the risk of OFCs. We focus on essential metabolic pathways, environmental signaling mechanisms, detoxification pathways, behavioral risk factors, and biological hazards that may disrupt orofacial development.

[Environmental factors of non-syndromic cleft lip and palate]

Though the mechanism of non-syndromic cleft lip and palate is not completely clear, the disease is affected by the combination of environment and genetics. Special environmental factors have the affect on the incidence of cleft palate. In this paper, the environmental factors related to the occurrence of non-syndromic cleft lip and palate were summarize from three aspects: poor living habits, chemical factors, age and health status of pregnant women during pregnancy. Based on the analysis of this paper, it will help to improve the health and living environment of pregnant women, so as to reduce the incidence of cleft palate.

Maternal periconceptional consumption of sprouted potato and risks of neural tube defects and orofacial clefts

BACKGROUND

The association between maternal consumption of sprouted potato during periconceptional period on the development of neural tube defects (NTDs) or orofacial clefts (OFCs) remains unclear. We aimed to examine the association between maternal consumption of sprouted potatoes during periconceptional period and risks of NTDs or OFCs.

METHODS

Subjects included 622 NTD cases, 135 OFC cases and 858 nonmalformed controls, were recruited from a case-control study in Shanxi Province of northern China between 2002 and 2007. Information on demographics, maternal sprouted potato consumption, lifestyle behaviors and folic acid supplementation was collected.

RESULTS

Consumption of sprouted potatoes was associated with elevated odds of total NTDs (OR = 2.20; 95% CI, 1.12-4.32) and anencephaly (OR = 2.48; 95% CI, 1.10-5.58); no association for spina bifida or encephalocele. Sprouted potato consumption increased the risk of total OFCs (OR = 3.49; 95% CI, 1.29-9.49) and cleft lip with or without cleft palate (CL ± P) (OR = 4.03; 95% CI, 1.44-11.28).

CONCLUSION

Maternal consumption of sprouted potatoes during periconceptional period may increase the risks of NTDs and OFCs. Given that potato is commonly consumed around the world, improper preservation and use should be a matter of concern in respect of the potential teratogenicity.

Folate transporter expression in placenta from pregnancies complicated with birth defects

BACKGROUND

Folate plays a fundamental role for fetal development, participating in cell division, embryogenesis, and fetal growth. The fetus depends on maternal supply of folate across the placenta. The objective of this study was to compare the expression of Folate Receptor-α (FR-α), Reduced Folate Carrier (RFC), and Proton Coupled Folate Transporter (PCFT) in placentas from pregnancies complicated with birth defects (BD) and controls.

METHODS

Case-control study, including placentas of BD-complicated pregnancies (n = 25) and a control group (n = 25). We determined the placental expression of FR-α, RFC, and PCFT by immunohistochemistry. Optical density was measured to obtain a relative quantification of the expression.

RESULTS

The expression of PCFT was greater in placentas from pregnancies complicated with BD than in those from the control group (p < .01). The expression of FR-α and RFC was not different between groups.

CONCLUSION

The expression of PCFT in placentas from BD-complicated pregnancies is increased, possibly as an adaptive response to increase the folate flux at the maternal-fetal interface.

Risk factors and comorbidities in Brazilian patients with orofacial clefts

Considering that environmental risk factors substantially contribute to the etiology of orofacial clefts and that knowledge about the characteristics and comorbidities associated with oral clefts is fundamental to promoting better quality of life, this study aimed to describe the risk factors, main characteristics, and comorbidities of a group of patients with cleft lip and/or cleft palate (CL/P) from Rio Grande do Norte (RN), Brazil. Data were obtained from 173 patients with CL/P using a form from the Brazilian database on Orofacial Clefts. Most patients were male with cleft lip and palate and had a normal size and weight at birth; presented few neonatal intercurrent events; and had anemia and respiratory and cardiovascular diseases as main associated comorbidities. They also required timely surgical rehabilitation and multidisciplinary care to stimulate their neuropsychomotor development. In addition, a high frequency of familial recurrence and of parental consanguinity was evidenced in the studied population, especially for the cleft lip and cleft palate type. Other relevant findings were the considerable maternal exposure to alcohol, infections, smoking, and hypertension, as well as low supplementation with vitamins and minerals and deliberate consumption of analgesics, antibiotics, and antihypertensives during pregnancy. Characterization of the CL/P patient profile is essential for the planning of health services and integration among the health professionals involved in the diagnosis and treatment of these malformations. Our results reinforce the need for additional research to confirm the association between environmental factors and the development of orofacial clefts.

Alterations in DNA methyltransferases and methyl-CpG binding domain proteins during cleft palate formation as induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in mice

Maternal exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces cleft palate formation in mice. This TCDD treatment, which may be considered an environmental factor in cleft palate formation, is associated with alterations in DNA methylation. However, the underlying molecular mechanisms of DNA methylation produced by TCDD in mouse embryos are poorly understood. DNA methyltransferases (DNMTs) and methyl‑CpG binding domain proteins (MBDs) are thought to be closely associated with the actions of DNA methylation. Therefore, the present study tested the hypothesis that this cleft palate inducing effect of TCDD will alter the expression levels of DNMTs and various MBDs in palate tissue of fetal mice. Pregnant C57BL/6J mice were treated with either TCDD (64 µg/kg) or corn oil (control) at embryonic day 10.5 (E10.5) and fetal palates were harvested for structural and molecular analyses at E13.5, E14.5, E15.5 and E17.5. Expression levels of DNMTs and MBDs were assayed using reverse transcription‑quantitative polymerase chain reaction and western blotting. The incidence of cleft palates in the TCDD group was 98.24%, whereas no cases of cleft palate were observed in the control group. Expression levels of DNMTs and MBDs were significantly increased in the TCDD group compared with the control. The results demonstrate clear alterations in DNMTs and MBDs, as induced by TCDD, and suggest that such alterations are important in cleft palate formation in fetal mice.

Individual deprivation, regional deprivation, and risk for oral clefts in Argentina

Objective. The aim of this study was to analyze the effects of individual low socioeconomic status (SES) and deprived geographical area (GA) on the occurrence of isolated cleft lip with or without cleft palate (CL±P) in Argentina.

Methods. This case-control study included 577 newborns with isolated CL±P and 13 344 healthy controls, born between 1992 and 2001, from a total population of 546 129 births in 39 hospitals in Argentina. Census data on unsatisfied basic needs were used to establish the degree of geographical area deprivation. An SES index for each individual was established, using maternal age, gravidity, low paternal and maternal education, and low-level paternal occupation. Logistic regression was used to assess the effects of low SES and of deprived GA on CL±P.

Results. A slightly increased risk of CL±P was observed in mothers with a low SES, while a deprived GA showed no effect. Native ancestry, acute maternal illnesses, and poor prenatal care were significant risk factors for CL±P for the mothers with low SES, after using propensity scores to adjust for the demographic characteristics in cases and controls.

Conclusions. Low individual SES slightly increased the risk for CL±P, but a deprived GA did not have that effect. There was no interaction between individual SES and deprived GA. Factors related to low individual SES—including poor prenatal care, low parental education, lack of information, and lifestyle factors—should be primarily targeted as risk factors for CL±P rather than factors related to a deprived place of residence.

Risk factors for orofacial clefts in India: A case-control study

Background

Orofacial clefts (OFC) are linked with several genetic and environmental factors. The aim of this study was to explore the association of potential risk factors with OFCs in India.

Methods

This was a hospital‐based, matched case–control (1:4 ratio; matching done for parity) study conducted in Hyderabad, Bengaluru, and Delhi‐National Capital Region. Cases (nonsyndromic clefts) were recruited from treatment centers, while controls (live births) were recruited from maternity centers. Information on exposures was collected during personal interviews. Exposures of interest included folic acid supplementation during the peri‐conceptional period, consanguineous marriage, exposure to drugs, infections during pregnancy, family history of OFC, and dietary factors.

Results

A total of 785 participants were included in the study: 157 cases and 628 controls. A family history of cleft lip/palate (adjusted odds ratio [AOR], 15.48; 95% confidence interval [CI], 4.36–54.96; p value = 0.001), exclusive vegetarianism (AOR, 4.47; 95% CI, 1.83–10.98; p value = 0.001), and delayed first conception (AOR, 2.55, 95% CI, 1.25–5.21, p = 0.01) were found to be strongly associated with higher risk of OFCs. Supplementation with folic acid during first 3 months of pregnancy was not found to be protective against OFCs (AOR, 1.24; 95% CI, 0.59–2.58; p value = 0.56).

Conclusion

Our study confirmed the importance of family history as a risk factor for OFC. Our study did not show an association with folic acid supplementation but was underpowered to detect small effects. Our finding of higher risk among vegetarians requires replication. Birth Defects Research 109:1284–1291, 2017. © 2017 Wiley Periodicals, Inc.

Effects of folic acid fortification on orofacial clefts prevalence: a meta-analysis

OBJECTIVE

Orofacial clefts (OFC) are the most prevalent craniofacial birth defect. Folic acid (FA) supplementation has been demonstrated as an effective intervention to reduce risk of OFC occurrence. However, the effect of mandatory FA fortification of wheat and/or maize flour on OFC prevalence has shown controversial results among countries adopting this policy. Thus, we performed a meta-analysis to synthesize the available evidence evaluating the global impact of this mandatory policy on OFC occurrence.

DESIGN

Literature search in conventional and grey medical/scientific databases showed fifteen studies considering OFC prevalence in pre- and post-fortification periods with FA. The effect of this policy was evaluated by computing relative risk (RR) and separating samples into total OFC, non-syndromic forms, cleft lip with or without cleft palate (CL/P) and cleft palate only (CPO).

RESULTS

We found a significant effect of FA fortification only on non-syndromic CL/P (RR=0·88; 95 % CI 0·81, 0·96), whereas neutral effects were detected for total OFC (syndromic plus non-syndromic) and CPO.

CONCLUSIONS

Our results may reflect the different aetiology of syndromic OFC with respect to non-syndromic forms and the CL/P related to CPO. Although the number of non-syndromic CL/P samples was lower than that for total OFC, the absence of both between-study heterogeneity and publication bias leads us to conclude that FA fortification may have beneficial effects on non-syndromic CL/P.

Neighborhood-Based Socioeconomic Position and Risk of Oral Clefts Among Offspring

OBJECTIVES

We determined the association between maternal neighborhood socioeconomic position (SEP) and the risk of cleft lip with or without cleft palate (CL±P) or cleft palate alone (CP) in offspring.

METHODS

We obtained information on CL±P (n = 2555) and CP (n = 1112) cases and unaffected controls (n = 14 735) among infants delivered during 1999 to 2008 from the Texas Birth Defects Registry. Neighborhood SEP variables, drawn from the 2000 US Census, included census tract-level poverty, education, unemployment, occupation, housing, and crowding, from which we created a composite neighborhood deprivation index (NDI). We used mixed-effects logistic regression to evaluate neighborhood SEP and oral clefts.

RESULTS

Mothers with CL±P-affected offspring were more likely to live in high-NDI (adverse) areas than mothers with unaffected offspring (odds ratio [OR] = 1.20, 95% confidence interval [CI] = 1.05, 1.37). This association was strongest among Hispanic mothers (OR = 1.32, 95% CI = 1.07, 1.62). No associations were observed with CP.

CONCLUSIONS

Using data from one of the world's largest active surveillance birth defects registries, we found that adverse neighborhood SEP is modestly associated with CL±P, especially among Hispanics. These findings may have important implications for health disparities prevention.