Genetics of nonsyndromic orofacial clefts

Pattern of Cleft Lip and Palate Clefts at a Tertiary Care Hospital in Saudi Arabia

BACKGROUND

Clefts of the lip and palate (CL/P) and cleft palate (CP) are the most common craniofacial congenital anomalies. Clefts are classified as syndromic and nonsyndromic. Nonsyndromic clefts have no known genetic causes.

OBJECTIVES

This study combines prospective and retrospective studies to review the patterns of CL/P and CP and associated syndromes and conditions in patients registered for CL/P surgery at a tertiary care pediatric center in our tertiary care hospital in Saudi Arabia.

METHODS

It included patient data from May 2015 through April 2023. Patient record forms and SPSS (IBM version 20.0) were used to collect and analyze data. A significance level of 5% was used, with p ≤ 0.05 considered statistically significant.

RESULTS

Of the 319 patients who met our inclusion criteria, 175 were male. Of the total, 99 had a left unilateral isolated cleft lip, 61 had a right unilateral isolated cleft lip, 69 had a bilateral cleft lip, and 90 had an isolated CP. Of the total, 140 had CL/P. Around 242 were nonsyndromic. The Chi-square test revealed a significant association between the prevalence of isolated CP and CLP and gender. The prevalence of left unilateral isolated cleft lip and bilateral and isolated CP was significantly associated with syndromic and nonsyndromic cases.

CONCLUSION

Males are more likely to be affected by orofacial clefts, which is consistent with the global trend. Isolated CP was the most common orofacial cleft. Within the sample, syndromes' association with orofacial clefts was significantly weaker than that of isolated and bilateral clefts.

Orofacial clefts in Costa Rica, 1996-2021: Analysis of surveillance data

BACKGROUND

Orofacial clefts (OFCs) are among the most common birth defects (BD). In 2008, a series of improvements began in the Costa Rican Birth Defect Register Center (CREC). We aim to explore trends between 1996 and 2021.

METHODS

A trend analysis of OFCs from 1996 to 2021 and a descriptive analysis of OFCs from 2010 to 2021 were performed based on data from the CREC, the national BD surveillance system. Prevalence at birth was calculated according to the type: cleft palate (CP), cleft lip with or without CP (CL ± P), and presentation (isolated, multiple non-syndromic, or syndromes). We used joinpoint regression to identify if a significant change in trend occurred; the average annual percent change (AAPC) was determined. Marginal means and prevalence ratios by subperiod (1996-2009 as referent and 2010-2021) were estimated using Poisson regression and compared using Wald's chi-square tests (α ≤.05).

RESULTS

We found a significant AAPC for OFCs prevalence of +1.4: +0.6 for isolated, +2.9 for multiple non-syndromic, and +7.7 for syndromes (p < .05). When comparing the OFC's prevalence of the subperiod 2010-2021 (11.86 per 10,000) with 1996-2009 (9.36 per 10,000) the prevalence ratio was 1.3 (p < .01): 1.1 (p < .05) for isolated, 1.6 (p < .01) for multiple non-syndromic, and 3.3 (p < .01) for syndromes. The prevalence of OFCs from 2010 to 2021 was 9.1 for CL ± P and 2.8 for CP. Seventy-one percent of the OFCs were isolated, 22% multiple non-syndromic, and 7% syndromes.

CONCLUSION

The trend in OFCs' prevalence is toward increasing, mainly due to improvements in the surveillance system.

Ground-truth validation of the "earbuds method" for measuring acoustic nasalance

Among the variety of methodological tools available for quantifying the degree of nasalization, nasometry has remained a popular choice for both academic and clinical research on speech due to its relatively low cost, portability, ease of use, and interpretability. In its simplest form, nasometry involves two microphones that independently capture the acoustic radiation from the mouth and nose. Recently, a method was proposed by Stewart and Kohlberger [(2017). Lang. Doc. Conserv. 11, 49-80] of using earbuds to achieve a similar result. Although the method has been widely used since, most notably in the context of linguistic fieldwork, it has yet to be tested against ground-truth measurements of acoustic nasalance from a commercially established device; the current study attempts to provide this ground-truth comparison. A wide variety of characteristics of the relationship between nasalance measurements created using acoustic data co-registered from a commercial nasometer, silicone earbuds, and flat earbuds are thoroughly examined. The results suggest that the "earbuds method" may provide reliable estimates of nasality when assessed at a global level (i.e., overall averages, relatively high/low nasalance scores coinciding with the presence/absence of nasalization), but that the accuracy of these estimates may decline at more fine-grained levels in different ways that are outlined in the discussion.

Single-Nucleotide Polymorphisms in WNT Genes in Patients with Non-Syndromic Orofacial Clefts in a Polish Population

Non-syndromic orofacial cleft (OFC) is the most common facial developmental defect in the global population. The etiology of these birth defects is complex and multifactorial, involving both genetic and environmental factors. This study aimed to determine if SNPs in the WNT gene family (rs1533767, rs708111, rs3809857, rs7207916, rs12452064) are associated with OFCs in a Polish population. The study included 627 individuals: 209 children with OFCs and 418 healthy controls. DNA was extracted from saliva for the study group and from umbilical cord blood for the control group. Polymorphism genotyping was conducted using quantitative PCR. No statistically significant association was found between four variants and clefts, with odds ratios for rs708111 being 1.13 (CC genotype) and 0.99 (CT genotype), for rs3809857 being 1.05 (GT genotype) and 0.95 (TT genotype), for rs7207916 being 0.86 (AA genotype) and 1.29 (AG genotype) and for rs12452064 being 0.97 (AA genotype) and 1.24 (AG genotype). However, the rs1533767 polymorphism in WNT showed a statistically significant increase in OFC risk for the GG genotype (OR = 1.76, p < 0.001). This research shows that the rs1533767 polymorphism in the WNT gene is an important risk marker for OFC in the Polish population.

Maternal factors in the origin of cleft lip/cleft palate: A population-based case-control study

OBJECTIVES

Orofacial clefts are among the most common birth defects, with an estimated worldwide incidence of around 1.5-1.7 per 1000 live-born babies. The most frequent form of orofacial clefts is cleft lip with or without cleft palate (CL ± CP). The role of environmental factors in the development of clefts is unclear in most patients, thus the aim of this study was to estimate possible maternal risk factors in the origin of CL ± CP.

MATERIALS AND METHODS

1648 CL ± CP cases, 2654 matched controls and 57 231 population controls were evaluated from The Hungarian Case-Control Surveillance of Congenital Abnormalities. Maternal factors during the critical period in cases and controls were compared. Adjusted odds ratios (OR) with 95% confidence intervals (CI) were estimated in a multivariable conditional logistic regression model.

RESULTS

Among socio-demographic data, we have found significant differences between maternal employment. The proportion of unskilled mothers (6.5%) were higher in the CL ± CP group than in controls (3.5%). Medically recorded maternal anaemia, excessive vomiting and threatened abortion were associated with a higher risk of CL ± CP. An elevated risk was also found in various acute illnesses such as influenza (OR: 2.4, 95% CI: 3.0-5.8), acute bronchitis (OR: 4.5, 95% CI: 1.6-12.6) and urinary tract infections (OR: 3.5, 95% CI: 2.0-6.0). Maternal migraine and essential hypertension occurred more frequently in the mothers of cases than in controls.

CONCLUSION

The findings of this study suggest that maternal diseases and lifestyle factors during the first trimester play a significant role in the development of CL ± CP.

Shared genetic risk between major orofacial cleft phenotypes in an African population

Nonsyndromic orofacial clefts (NSOFCs) represent a large proportion (70%-80%) of all OFCs. They can be broadly categorized into nonsyndromic cleft lip with or without cleft palate (NSCL/P) and nonsyndromic cleft palate only (NSCPO). Although NSCL/P and NSCPO are considered etiologically distinct, recent evidence suggests the presence of shared genetic risks. Thus, we investigated the genetic overlap between NSCL/P and NSCPO using African genome-wide association study (GWAS) data on NSOFCs. These data consist of 814 NSCL/P, 205 NSCPO cases, and 2159 unrelated controls. We generated common single-nucleotide variants (SNVs) association summary statistics separately for each phenotype (NSCL/P and NSCPO) under an additive genetic model. Subsequently, we employed the pleiotropic analysis under the composite null (PLACO) method to test for genetic overlap. Our analysis identified two loci with genome-wide significance (rs181737795 [p = 2.58E-08] and rs2221169 [p = 4.5E-08]) and one locus with marginal significance (rs187523265 [p = 5.22E-08]). Using mouse transcriptomics data and information from genetic phenotype databases, we identified MDN1, MAP3k7, KMT2A, ARCN1, and VADC2 as top candidate genes for the associated SNVs. These findings enhance our understanding of genetic variants associated with NSOFCs and identify potential candidate genes for further exploration.

Genetic association and functional validation of ZFP36L2 in non-syndromic orofacial cleft subtypes

BACKGROUND

Non-syndromic orofacial cleft (NSOC) is one of the most common craniofacial malformations with complex etiology. This study aimed to explore the role of specific SNPs in ZFP36L2 and its functional relevance in zebrafish models.

METHODS

We analyzed genetic data of the Chinese Han population from two previous GWAS, comprising of 2512 cases and 2255 controls. Based on the Hardy-Weinberg Equilibrium (HWE) and minor allele frequency (MAF), SNPs in the ZFP36L2 were selected for association analysis. In addition, zebrafish models were used to clarify the in-situ expression pattern of zfp36l2 and the impact of its Morpholino-induced knockdown.

RESULTS

Via association analysis, rs7933 in ZFP36L2 was significantly associated with various non-syndromic cleft lip-only subtypes, potentially conferring a protective effect. Zebrafish embryos showed elevated expression of zfp36l2 in the craniofacial region during critical stages of oral cavity formation. Furthermore, Morpholino-induced knockdown of zfp36l2 led to craniofacial abnormalities, including cleft lip, which was partially rescued by the addition of zfp36l2 mRNA.

CONCLUSION

Our findings highlight the significance of ZFP36L2 in the etiology of NSOC, supported by both human genetic association data and functional studies in zebrafish. These results pave the way for further exploration of targeted interventions for craniofacial malformations.

Damaging Mutations in Contribute to Risk of Nonsyndromic Cleft Lip With or Without Cleft Palate

Novel or rare damaging mutations have been implicated in the developmental pathogenesis of nonsyndromic cleft lip with or without cleft palate (nsCL ± P). Thus, we investigated the human genome for high-impact mutations that could explain the risk of nsCL ± P in our cohorts.

We conducted next-generation sequencing (NGS) analysis of 130 nsCL ± P case-parent African trios to identify pathogenic variants that contribute to the risk of clefting. We replicated this analysis using whole-exome sequence data from a Brazilian nsCL ± P cohort. Computational analyses were then used to predict the mechanism by which these variants could result in increased risks for nsCL ± P.

We discovered damaging mutations within the AFDN gene, a cell adhesion molecule (CAMs) that was previously shown to contribute to cleft palate in mice. These mutations include p.Met1164Ile, p.Thr453Asn, p.Pro1638Ala, p.Arg669Gln, p.Ala1717Val, and p.Arg1596His. We also discovered a novel splicing p.Leu1588Leu mutation in this protein. Computational analysis suggests that these amino acid changes affect the interactions with other cleft-associated genes including nectins (PVRL1, PVRL2, PVRL3, and PVRL4) CDH1, CTNNA1, and CTNND1.

This is the first report on the contribution of AFDN to the risk for nsCL ± P in humans. AFDN encodes AFADIN, an important CAM that forms calcium-independent complexes with nectins 1 and 4 (encoded by the genes PVRL1 and PVRL4). This discovery shows the power of NGS analysis of multiethnic cleft samples in combination with a computational approach in the understanding of the pathogenesis of nsCL ± P.

Care of an infant born with a cleft palate: a case study

Orofacial clefts are the most common facial congenital abnormalities in humans. Their management is complex due to a range of immediate and ongoing challenges. These include breathing, feeding, speech, hearing and dental issues. This article uses a case study approach to outline these challenges for a patient who was born with a cleft palate. The case is followed by a discussion of contemporary evidence-based care. The article focuses on family-centred care and multidisciplinary teamwork, and the author also details the central role of the children's nurse.

Evaluating Dental Arch Relationships in Indonesian Patients with Operated Bilateral Cleft Lip and Palate Using Modified Huddart/Bodenham Index and Bauru-bilateral cleft lip and palate (BCLP) Yardstick

Background

Patients with complete bilateral cleft lip and palate (CBCLP) have the most complex orofacial abnormalities despite its lowest incidence among cleft lip and palate (CLP) types. Impaired maxillary growth can result from surgical procedures in patients with CBCLP. This study evaluates dental arch relationships in Indonesian patients with CBCLP after undergoing CLP repair at Harapan Kita Children and Mother Hospital in Jakarta.

Material and Methods

Using the modified Huddart and Bodenham (MHB) index and Bauru bilateral cleft lip and palate (BCLP) yardstick, three examiners assessed 17 study models in the 9-year age group and 13 study models in the 12-year age group, as well as two intraoral clinical photographs of two patients with CBCLP. The assessments were repeated three times within two weeks of each assessment time.

Results

Patients with operated CBCLP (aged 9 and 12 years) had edge-to-edge tooth relations, which were categorized as a mild crossbite or mild deviation, and only required orthodontic treatment according to the two specified indicators.

Conclusions

The CLP repair protocol used at the Harapan Kita Hospital effectively manages CBCLP cases with satisfactory results, suggesting the effectiveness of the MHB index and Bauru-BCLP yardstick in assessing dental arch relationships in patients with operated CBCLP. Key words:Bilateral, cleft lip and palate, dental arch relationship, lip repair, palate repair.

A comprehensive consolidation of data on the relationship between IRF6 polymorphisms and non-syndromic cleft lip/palate susceptibility: From 79 case-control studies

BACKGROUND

Non-syndromic cleft lip with or without cleft palate (NSCL/P) is a prevalent craniofacial birth defect on a global scale. A number of candidate genes have been identified as having an impact on NSCL/P. However, the association between interferon regulatory factor 6 (IRF6) polymorphisms and NSCL/P has yielded inconsistent results, prompting the need for a meta-analysis to obtain more accurate estimates.

METHODS

We conducted a thorough screening of all relevant articles published up until November 15, 2023, in online bibliographic databases. The statistical analysis of the collected data was performed using the Comprehensive Meta-Analysis (Version 4.0) software.

RESULTS

A total of 79 case-control studies, comprising 14,003 cases and 19,905 controls, were included in our analysis. The combined data indicated that the IRF6 rs642961 and rs2235371 polymorphisms were associated with an increased risk of NSCL/P in the overall population. However, no significant association was found between the rs2013162 and rs2235375 polymorphisms and the risk of NSCL/P in the overall population. Furthermore, subgroup analyses revealed significant correlations between the IRF6 rs642961, rs2235371, and rs2235375 polymorphisms and the risk of NSCL/P based on ethnic background and country of origin. Nevertheless, the rs2013162 polymorphism plays a protective role in Caucasians and mixed populations.

CONCLUSIONS

Our collective data indicates a significant association between the rs642961 and rs2235371 polymorphisms and the risk of NSCL/P in the overall population. The rs2235375 polymorphism could influence the susceptibility to NSCL/P based on ethnic background. Meanwhile, the rs2013162 polymorphism provides protective effects in Caucasian, mixed populations, and the Brazilian population.

A screen of mutants generated and imaged by the International Mouse Phenotyping Consortium identifies 39 novel genes regulating the development of the secondary palate

The International Mouse Phenotyping Consortium (IMPC) has generated thousands of knockout mouse lines, of which a large proportion is embryonic or early neonatal lethal. The IMPC has generated and imaged embryos from lethal lines and made the three-dimensional image data sets publicly available. In this study, we used this resource to screen homozygous null mutants for defects in the development of the secondary palate. Altogether, we analyzed optical sections from 3216 embryos isolated at embryonic day (E) 15.5 and E18.5 from 478 homozygous mutant lines. Through this analysis, we discovered 39 novel genes important for palatal development. These studies provide new insights into the molecular regulation of palatogenesis and craniofacial disease and offer a useful resource for future exploration.

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.

Posttraumatic Growth and its Correlates Among Parents of Children With Cleft Lip and/or Palate

This study examined the posttraumatic growth (PTG) about parents of children with cleft lip and/or palate (CL/P) and the correlates of PTG.

A cross-sectional study.

Parents (N = 388) of children with isolated CL/P (ages 3 months-18 years) who had at least one cleft surgery within an oral and maxillofacial surgery department of a university-affiliated tertiary hospital in a provincial capital in southwest China.

Demographic information questionnaire, The Posttraumatic Growth Inventory, Simplified Coping Style Questionnaire, and Social Support Rating Scale were used for data collection.

Parents' mean PTG score was in the moderate range (M = 65.7, SD = 13.73). PTG differed regarding the participants' sex, ethnicity, and educational background. Pearson's correlation analysis revealed that positive coping (r = 0.43, P < .01), negative coping (r = 0.13, P < .01), and social support (r = 0.26, P < .01) were positively correlated with PTG. Multiple regression model showed that 20.6% (P < .001) of the variance in PTG was explained by higher positive coping (β = 0.35, P < .001), greater social support (β = 0.13, P = .01), and for cleft lip compared to cleft palate (β = -0.14, P ≤ .01), with no variance difference for cleft lip and palate.

Parents of children with CL/P had moderate PTG. Potentially modifiable correlates of PTG suggest interventions to enhance parental positive coping and social support may increase PTG. Further studies are needed to confirm the PTG level and its affecting factors of parents of children with CL/P.

Sociodemographic Factors Associated with Knowledge About Management of Cleft Lip and Palate Patients in Peruvian Dental Students: A Logistic Regression Analysis

Background

Cleft lip and palate are relatively frequent craniofacial alterations caused by the lack of union of the frontonasal processes with the maxillary processes during the first weeks of intrauterine life. This study evaluated the sociodemographic factors associated with the level of knowledge about management of cleft lip and palate (CLP) patients in Peruvian dental students.

Methods

This analytical, observational, cross-sectional and prospective study evaluated 191 dental students belonging to two branches of a private Peruvian university (one branch in the capital city and the other in a province), from September to November 2022. A validated questionnaire of 14 closed multiple-choice questions was used. A logit model was used to evaluate the influence of the variables: sex, age, academic year of study, marital status, relationship with CLP persons, place of origin and area of residence, on the level of knowledge of the students considering a significance level of p<0.05.

Results

Of the total, 77%, 22.5% and 0.5% presented a poor, fair and good level of knowledge, respectively, on the dental management of the patient with cleft lip and palate. In addition, those who lived in urban areas were 2.8 times more likely to have poor knowledge about the dental management of patients with CLP, compared to those who lived in non-urban areas (OR = 2.83; 95% CI: 1.26-6.33). Finally, sex, age, marital status, place of origin, academic year of studies and relationship with CLP persons were not considered influential factors (p>0.05).

Conclusion

Most of the students showed a poor level of knowledge about the dental management of patients with cleft lip and palate, a risk factor being that the students live in an urban area. It is recommended that educational authorities include selected topics on CLP in subjects related to infant, child and adolescent care.

Longitudinal Three-Dimensional Stereophotogrammetric Growth Analysis in Infants with Unilateral Cleft Lip and Palate from 3 to 12 Months of Age

This longitudinal study aimed to evaluate facial growth and soft tissue changes in infants with complete unilateral cleft lip, alveolus, and palate (CUCLAP) at ages 3, 9, and 12 months. Using 3D images of 22 CUCLAP infants, average faces and distance maps for the entire face and specific regions were created. Color-coded maps highlighted more significant soft tissue changes from 3 to 9 months than from 9 to 12 months. The first interval showed substantial growth in the entire face, particularly in the forehead, eyes, lower lip, chin, and cheeks (p < 0.001), while the second interval exhibited no significant growth. This study provides insights into facial soft tissue growth in CUCLAP infants during critical developmental stages, emphasizing substantial improvements between 3 and 9 months, mainly in the chin, lower lip, and forehead. However, uneven growth occurred in the upper lip, philtrum, and nostrils throughout both intervals, with an overall decline in growth from 9 to 12 months. These findings underscore the dynamic nature of soft tissue growth in CUCLAP patients, highlighting the need to consider these patterns in treatment planning. Future research should explore the underlying factors and develop customized treatment interventions for enhanced facial aesthetics and function in this population.

Genetic Inheritance Models of Non-Syndromic Cleft Lip with or without Palate: From Monogenic to Polygenic

Non-syndromic cleft lip with or without palate (NSCL/P) is a prevalent birth defect that affects 1/500-1/1400 live births globally. The genetic basis of NSCL/P is intricate and involves both genetic and environmental factors. In the past few years, various genetic inheritance models have been proposed to elucidate the underlying mechanisms of NSCL/P. These models range from simple monogenic inheritance to more complex polygenic inheritance. Here, we present a comprehensive overview of the genetic inheritance model of NSCL/P exemplified by representative genes and regions from both monogenic and polygenic perspectives. We also summarize existing association studies and corresponding loci of NSCL/P within the Chinese population and highlight the potential of utilizing polygenic risk scores for risk stratification of NSCL/P. The potential application of polygenic models offers promising avenues for improved risk assessment and personalized approaches in the prevention and management of NSCL/P individuals.

Identification of a Novel Variant of PDGFC Associated with Nonsyndromic Cleft Lip and Palate in a Chinese Family

Nonsyndromic cleft lip with or without cleft palate (NSCL/P) accounts for 70% of the total number of patients with cleft lip with or without cleft palate (CL/P) and is the most common type of congenital deformity of the craniomaxillofacial region. In this study, whole exome sequencing (WES) and Sanger sequencing were performed on affected members of a Han Chinese family, and a missense variant in the platelet-derived growth factor C (PDGFC) gene (NM_016205: c.G93T: p.Q31H) was identified to be associated with NSCL/P. Bioinformatic studies demonstrated that the amino acid corresponding to this variation is highly conserved in many mammals and leads to a glutamine-to-histidine substitution in an evolutionarily conserved DNA-binding domain. It was found that the expression of PDGFC was significantly decreased in the dental pulp stem cells (DPSCs) of NSCL/P cases, compared to the controls, and that the variant (NM_016205: c.G93T) reduced the expression of PDGFC. In addition, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that Pdgfc deficiency disrupted NSCL/P-related signaling pathways such as the MAPK signaling pathway and cell adhesion molecules. In conclusion, our study identified a missense variant (NM_016205: c.G93T) in exon 1 of PDGFC potentially associated with susceptibility to NSCL/P.

Neural crest E-cadherin loss drives cleft lip/palate by epigenetic modulation via pro-inflammatory gene-environment interaction

Gene-environment interactions are believed to play a role in multifactorial phenotypes, although poorly described mechanistically. Cleft lip/palate (CLP), the most common craniofacial malformation, has been associated with both genetic and environmental factors, with little gene-environment interaction experimentally demonstrated. Here, we study CLP families harbouring CDH1/E-Cadherin variants with incomplete penetrance and we explore the association of pro-inflammatory conditions to CLP. By studying neural crest (NC) from mouse, Xenopus and humans, we show that CLP can be explained by a 2-hit model, where NC migration is impaired by a combination of genetic (CDH1 loss-of-function) and environmental (pro-inflammatory activation) factors, leading to CLP. Finally, using in vivo targeted methylation assays, we demonstrate that CDH1 hypermethylation is the major target of the pro-inflammatory response, and a direct regulator of E-cadherin levels and NC migration. These results unveil a gene-environment interaction during craniofacial development and provide a 2-hit mechanism to explain cleft lip/palate aetiology.

Genetic Variants in Mammalian STE20-like Protein Kinase 2 were associated with risk of NSCL/P

AIM

Mammalian STE20-like protein kinase 2 (MST2) plays an important role in apoptosis and the development of many disorders. Here, we aim to explore if genetic variants in MST2 are associated with the risk of non-syndromic cleft lip with or without palate (NSCL/P).

MATERIALS AND METHODS

The association study was performed in a two-stage study of 1,069 cases and 1,724 controls to evaluate the association between genetic variants in the MST2 and NSCL/P risk. The potential function of the candidate single nucleotide polymorphism (SNP) was predicted using HaploReg, RegulomeDB, and public craniofacial histone chromatin immunoprecipitation sequencing (ChIP-seq) data. Haploview was used to perform the haplotype of risk alleles. The expression quantitative trait loci (eQTL) effect was assessed using the Genotype-Tissue Expression (GTEx) project. Gene expression in mouse embryo tissue was performed using data downloaded from GSE67985. The potential role of candidate gene in the development of NSCL/P was assessed by correlation and enrichment analysis.

RESULTS

Among SNPs in MST2, rs2922070 C allele (P_meta = 2.93E-04) and rs6988087 T allele (P_meta = 1.57E-03) were linked with significantly increased risk of NSCL/P. Rs2922070, rs6988087 and their high linkage disequilibrium (LD) SNPs constituted a risk haplotype of NSCL/P. Individuals carrying 3-4 risk alleles had an elevated risk of NSCL/P compared to those who carried less risk alleles (P = 2.00E-04). The eQTL analysis revealed a significant association between these two variants and MST2 in muscle tissue of the body. The MST2 expressed during mouse craniofacial development and over-expressed in the human orbicularis oris muscle (OOM) of NSCL/P patients compared to controls. MST2 was involved in the development of NSCL/P by regulating the mRNA surveillance pathway, the MAPK signaling pathway, the neurotrophin signaling pathway, the FoxO signaling pathway and the VEGF signaling pathway.

CONCLUSION

MST2 was associated with the development of NSCL/P.

LncRNA-NONMMUT100923.1 regulates mouse embryonic palatal shelf adhesion by sponging miR-200a-3p to modulate medial epithelial cell desmosome junction during palatogenesis

Cleft palate (CP) is a common neonatal craniofacial defect caused by the adhesion and fusion dysfunction of bilateral embryonic palatal shelf structures. Long non-coding RNA (lncRNA) is involved in CP formation with regulatory mechanism unknown. In this study, all-trans retinoic acid (ATRA) was used to induced cleft palate in embryonic mice as model group. The RNA-sequencing was performed to screen differentially expressed genes between the normal and model group on embryonic day 16.5, and the expression of LncRNA-NONMMUT100923.1 and miR-200a-3p, Cdsn was confirmed by RT-PCR and western blotting. Colony formation, CCK-8 and EDU assays were performed to measure cell proliferation and apoptosis on mouse embryonic palatal shelf (MEPS) epithelial cells in vitro. Fluorescence in situ hybridization (FISH) and dual luciferase activity assays was used to investigate the regulatory effect of LncRNA-NONMMUT100923.1 on miRNA and its target genes. Up-regulation of LncRNA-NONMMUT100923.1 and Cdsn while downregulation of miR-200a-3p was found in the model group. The sponging effects of LncRNA-NONMMUT100923 on miR-200a-3p and the target gene relations between Cdsn and miR-200a-3p was confirmed. Low expression of miR-200a-3p was related to the increased expressed levels of Cdsn and the proliferation of MEPS epithelial cells. Thus, a potential ceRNA regulatory network in which LncRNA-NONMMUT100923.1 regulates Cdsn expression by competitively binding to endogenous miR-200a-3p during palatogenesis, which may inhibit MEPS adhesion by preventing the disintegration of the desmosome junction in medial edge epithelium cells. These findings indicate the regulatory role of lncRNA and provides a potential direction for target gene therapy of CP.

Evidence of the folate-mediated one-carbon metabolism pathway genes in controlling the non-syndromic oral clefts risks

The folate-mediated one-carbon metabolism pathway is thought to play an important role in the etiology of non-syndromic oral clefts (NSOFC), although none of the genes in this pathway has shown significant signals in genome-wide association studies (GWAS). Recent evidence indicated that enhanced understanding could be gained by aggregating multiple SNPs effect simultaneously into polygenic risk score (PRS) to assess its association with disease risks. This study is aimed to assess the association between the genetic effect of folate-mediated one-carbon metabolism pathway and NSOFC risks using PRS based on a case-parent trio design. A total of 297 SNPs mapped from 18 genes in the folate-mediated one-carbon metabolism pathway were aggregated from a GWAS of 2458 case-parent trios recruited from an international consortium. We found a PRS based on the folate-mediated one-carbon metabolism pathway was significant among all NSOFC trios (OR = 1.95, 95% CI: 1.66-2.28, p = 2.39 × 10^-16 ), as well as two major subtypes, non-syndromic cleft lip with or without cleft palate (NSCL/P) trios (OR = 1.71, 95% CI: 1.50-1.96, p = 7.66 × 10^-15 ) and non-syndromic cleft palate only (NSCPO) trios (OR = 1.51, 95% CI: 1.36-1.68, p = 2.1 × 10^-14 ). Similar results were also observed in further subgroup analyses stratified into Asian and European trios. The averaged PRS of the folate-mediated one-carbon metabolism pathway varied between the NSOFC case group and its comparison group (p < 0.05) with higher average PRS in the cases. Moreover, the top 5% pathway PRS group had 2.25 (95% CI: 1.85-2.73) times increased NSOFC risk, also 3.09 (95% CI: 2.50-3.81) and 2.06 (95% CI: 1.39-3.02) times increased risk of NSCL/P and NSCPO compared to the remainder of the distribution. The results of our study confirmed the folate-mediated one-carbon metabolism pathway was important in controlling risk to NSOFC and this study enhanced evidence towards understanding the genetic risks of NSOFC.

Single visit rehabilitation of 12-day neonate with cleft palate using modified feeding spoon impression technique: A case report

The rehabilitation of the cleft requires a multidisciplinary approach involving a pediatrician, surgeon, otolaryngologist, speech therapist, orthodontist, prosthodontist, and psychologist. The present case report illustrates the rehabilitation of a 12-day-old neonate with a cleft palate. Since the palatal arch of the neonate was very small, a feeding spoon was innovatively modified to obtain the impression. The obturator was fabricated on the same day and delivered in one appointment.

Expression and function of patatin-like phospholipase domain-containing 2 in cleft palate induced by retinoic acid

Cleft palate is a common maxillofacial congenital malformation, and its mechanism still has not been fully illustrated. Recently, lipid metabolic defects have been observed in cleft palate. Patatin-like phospholipase domain-containing 2 (Pnpla2) is an important lipolytic gene. However, its effect on the formation of cleft palate remains unknown. In this research, we explored the expression of Pnpla2 in the palatal shelves of control mice. We also studied mice with cleft palates induced by retinoic acid and its effect on the embryonic palatal mesenchyme (EPM) cells phenotype. We found that Pnpla2 was expressed in the palatal shelves of both the cleft palate and control mice. Pnpla2 expression was lower in cleft palate mice than in the control mice. Experiments with EPM cells showed that knockdown of Pnpla2 inhibited cell proliferation and migration. In conclusion, Pnpla2 is linked to palatal development. We have indicated that low expression of Pnpla2 affects palatogenesis by inhibiting the proliferation and migration of EPM cells.

A Comprehensive Genetic Analysis of Slovenian Families with Multiple Cases of Orofacial Clefts Reveals Novel Variants in the Genes IRF6, GRHL3, and TBX22

Although the aetiology of non-syndromic orofacial clefts (nsOFCs) is usually multifactorial, syndromic OFCs (syOFCs) are often caused by single mutations in known genes. Some syndromes, e.g., Van der Woude syndrome (VWS1; VWS2) and X-linked cleft palate with or without ankyloglossia (CPX), show only minor clinical signs in addition to OFC and are sometimes difficult to differentiate from nsOFCs. We recruited 34 Slovenian multi-case families with apparent nsOFCs (isolated OFCs or OFCs with minor additional facial signs). First, we examined IRF6, GRHL3, and TBX22 by Sanger or whole exome sequencing to identify VWS and CPX families. Next, we examined 72 additional nsOFC genes in the remaining families. Variant validation and co-segregation analysis were performed for each identified variant using Sanger sequencing, real-time quantitative PCR and microarray-based comparative genomic hybridization. We identified six disease-causing variants (three novel) in IRF6, GRHL3, and TBX22 in 21% of families with apparent nsOFCs, suggesting that our sequencing approach is useful for distinguishing syOFCs from nsOFCs. The novel variants, a frameshift variant in exon 7 of IRF6, a splice-altering variant in GRHL3, and a deletion of the coding exons of TBX22, indicate VWS1, VWS2, and CPX, respectively. We also identified five rare variants in nsOFC genes in families without VWS or CPX, but they could not be conclusively linked to nsOFC.

Elevated concentrations of chromium in maternal serum, umbilical cord serum, and cord tissue are associated with an increased risk for orofacial clefts

Chromium (Cr) exposure during gestation causes malformations in animal experiments. In this multicenter case-control study, we initially involved 130 orofacial clefts (OFCs) and 260 controls to assess the association between Cr concentration and risk for OFCs. Then, umbilical cord serum (49 vs. 119) and cord tissue (84 vs. 142) were used to validate the association between Cr and OFCs. We found that maternal serum Cr concentrations in OFC cases were significantly higher than those in controls. Compared with the lowest tertile of maternal serum Cr concentration, the highest tertile of Cr increased the risk for OFCs [OR = 2.14 (1.14-4.05)]. In the validation cohort of umbilical cord serum and tissue, higher concentrations of Cr were associated with increased risks for OFCs in a dose-dependent manner (all Ps for trends <0.05). Cr concentrations in maternal serum and cord serum showed a positive correlation. The Cr concentration in cord serum was inversely correlated with egg and milk consumption frequencies, and the Cr concentration in cord tissue was positively associated with indoor coal burning. In conclusion, prenatal Cr exposure is a risk factor for OFCs, and indoor coal burning during pregnancy may be one of the sources of Cr exposure.

Variant analyses of candidate genes in orofacial clefts in multi-ethnic populations

OBJECTIVES

Cleft lip with/without cleft palate and cleft palate only is congenital birth defects where the upper lip and/or palate fail to fuse properly during embryonic facial development. Affecting ~1.2/1000 live births worldwide, these orofacial clefts impose significant social and financial burdens on affected individuals and their families. Orofacial clefts have a complex etiology resulting from genetic variants combined with environmental covariates. Recent genome-wide association studies and whole-exome sequencing for orofacial clefts identified significant genetic associations and variants in several genes. Of these, we investigated the role of common/rare variants in SHH, RORA, MRPL53, ACVR1, and GDF11.

MATERIALS AND METHODS

We sequenced these five genes in 1255 multi-ethnic cleft lip with/without palate and cleft palate only samples in order to find variants that may provide potential explanations for the missing heritability of orofacial clefts. Rare and novel variants were further analyzed using in silico predictive tools.

RESULTS

Ninteen total variants of interest were found, with variant types including stop-gain, missense, synonymous, intronic, and splice-site variants. Of these, 3 novel missense variants were found, one in SHH, one in RORA, and one in GDF11.

CONCLUSION

This study provides evidence that variants in SHH, RORA, MRPL53, ACVR1, and GDF11 may contribute to risk of orofacial clefts in various populations.

Targeted re-sequencing on 1p22 among non-syndromic orofacial clefts from Han Chinese population

Rs560426 at 1p22 was proved to be associated with NSCL/P (non-syndromic cleft lip with or without the palate) in several populations, including Han Chinese population. Here, we conducted a deep sequencing around rs560426 to locate more susceptibility variants in this region. In total, 2,293 NSCL/P cases and 3,235 normal controls were recruited. After sequencing, association analysis was performed. Western blot, RT-qPCR, HE, immunofluorescence staining, and RNA sequencing were conducted for functional analyses of the selected variants. Association analysis indicated that rs77179923 was the only SNP associated with NSCLP specifically (p = 4.70E-04, OR = 1.84), and rs12071152 was uniquely associated with LCLO (p = 4.00E-04, OR = 1.30, 95%CI: 1.12–1.51). Moreover, de novo harmful rare variant NM_004815.3, NP_004806.3; c.1652G>C, p.R551T in ARHGAP29 resulted in a decreased expression level of ARHGAP29, which in turn affected NSCL/P-related biological processes; however, no overt cleft palate (CP) phenotype was observed. In conclusion, rs12071152 was a new susceptible variant, which is specifically associated with LCLO among the Han Chinese population. Allele A of it could increase the risk of having a cleft baby. Rs77179923 and rare variant NM_004815.3, NP_004806.3; c.1652G>C, p.R551T at 1p22 were both associated with NSCLP among the Han Chinese population. However, this missense variation contributes to no overt CP phenotype due to dosage insufficiency or compensation from other genes.

Whole-genome sequencing reveals de-novo mutations associated with nonsyndromic cleft lip/palate

The majority (85%) of nonsyndromic cleft lip with or without cleft palate (nsCL/P) cases occur sporadically, suggesting a role for de novo mutations (DNMs) in the etiology of nsCL/P. To identify high impact protein-altering DNMs that contribute to the risk of nsCL/P, we conducted whole-genome sequencing (WGS) analyses in 130 African case-parent trios (affected probands and unaffected parents). We identified 162 high confidence protein-altering DNMs some of which are based on available evidence, contribute to the risk of nsCL/P. These include novel protein-truncating DNMs in the ACTL6A, ARHGAP10, MINK1, TMEM5 and TTN genes; as well as missense variants in ACAN, DHRS3, DLX6, EPHB2, FKBP10, KMT2D, RECQL4, SEMA3C, SEMA4D, SHH, TP63, and TULP4. Many of these protein-altering DNMs were predicted to be pathogenic. Analysis using mouse transcriptomics data showed that some of these genes are expressed during the development of primary and secondary palate. Gene-set enrichment analysis of the protein-altering DNMs identified palatal development and neural crest migration among the few processes that were significantly enriched. These processes are directly involved in the etiopathogenesis of clefting. The analysis of the coding sequence in the WGS data provides more evidence of the opportunity for novel findings in the African genome.

Nasolabial Appearance in 5-Year-Old Patients with Repaired Complete Unilateral Cleft Lip and Palate: A Comparison of Two Different Techniques of Lip Repair

Different surgical techniques are available to adequately correct the primary cleft lip deformity; however, when compared, none of these techniques have proven superior with regard to achieving optimal aesthetic results. Thus, the aim of this retrospective study was to assess the nasolabial appearance in patients with unilateral cleft lip and palate (UCLP) at age five with reference to two techniques for primary cleft lip repair used in our service: Pfeifer’s wave-line procedure and Randall’s technique. A modified Asher–McDade Aesthetic Index was applied to appraise the nasolabial area by means of 2D photographs of non-syndromic five-year-old patients with a UCLP. In this context, three parameters were assessed: 1. nasal frontal view; 2. shape of the vermilion border and philtrum length; and 3. the nasolabial profile. Five professionals experienced in cleft care were asked to rate the photographs on two occasions. Overall, 53 patients were included in the final analysis, 28 of whom underwent lip repair according to Pfeifer; 25 were treated employing Randall’s technique. Statistically significant differences between the two techniques regarding philtrum length and vermilion border were found (p = 0.046). With reference to the other parameters assessed, no significant differences were determined. The results suggest that Randall’s cleft lip repair may allow for more accurate alignment of the vermilion border and more adequate correction of the cleft lip length discrepancy in comparison to Pfeifer’s wave-line technique.

Differences in specific concerns perceived by parents of children with cleft lip and/or palate based on the types of cleft

BACKGROUND

Parents of children with cleft lip and/or palate (CL/P) have concerns including guilt and worry. Differences in concerns by cleft type is, however, under-researched.

AIM

To compare differences in perceived concerns among parents of children with CL/P by cleft type, adjusting for children's gender and age.

DESIGN

Cross-sectional study conducted in an outpatient centre, assessing psychological status of 171 parents of children aged <12 with CL/P using 12 items.

RESULTS

Across cleft types, 'I am worried about whether the child's teeth will be straight' was the most strongly perceived concern (70.8%). After adjusting for gender and age, logistic regression showed significant differences in type of CL/P for (eg) 'I am worried that the child's appearance will not be beautiful', associated with CL over CP (OR = 0.07, 95% CI: 0.02-0.26) and CLP over CP (8.52, 3.23-22.50);' 'I am concerned about my child being able to speak well', associated with CP (3.12, 1.07-9.11) and CLP (5.69, 2.43-13.33) over CL, and 'I am worried that the child could suffer due to his/her appearance', associated with CL over CP (0.08, 0.02-0.29) and CLP over CP (10.07, 13.78-27.36).

CONCLUSIONS

Parents' concerns were influenced by cleft type.

The genetic factors contributing to the risk of cleft lip-cleft palate and their clinical utility

Cleft lip and cleft palate (CL/P) are among the most common congenital malformations in neonates and have syndromic or nonsyndromic forms. Nonsyndromic forms of malformation are being reported to be associated with chromosomal DNA modification by teratogenic exposure and to complex genetic contributions of multiple genes. Syndromic forms are shown to be related to chromosomal aberrations or monogenic diseases. There is a growing body of data illustrating the association of several genes with risk of developing this malformation, including genetic defects in T-box transcription factor-22 (TBX22), interferon regulatory factor-6 (IRF6), and poliovirus receptor-like-1 (PVRL1), responsible for X-linked cleft palate, cleft lip/palate-ectodermal dysplasia syndrome, and Van der Woude and popliteal pterygium syndromes, respectively. Genetic variants in MTR, PCYT1A, ASS1, SLC 25A13, GSTM1, GSTT1, SUMO1 BHMT1, and BHMT2 are being reported to be linked with CL/P risk. The etiology of nonsyndromic CLP is still remained to be unknown, although mutations in candidate genes have been found. Here, we provide an overview about the potential variants to be associated with CL/P for identification of the relative risk of CLP with respect to the basis of genetic background and environmental factors (e.g., dietary factors, alcohol use).

The Evaluation of FGFR1, FGFR2 and FOXO1 in Orofacial Cleft Tissue

Although cleft lip with or without cleft palate (CL/P) is one of the most common congenital anomalies worldwide, the morphopathogenesis of non-syndromic orofacial clefts is still unclear. Many candidate genes have been proposed to play a causal role; however, only a few have been confirmed, leaving many still to be assessed. Taking into account the significance of FGFR1, FGFR2 and FOXO1 in embryogenesis, the aim of this work was to detect and compare the three candidate genes in cleft-affected lip and palatine tissue. Ten soft tissue samples were taken during cheiloplasty and veloplasty. The signals of the candidate genes were visualized using chromogenic in situ hybridization and analyzed using a semi-quantitative method. No statistically important difference in the distribution of FGFR1, FGFR2 and FOXO1 between neither the patients’ lip and vomer mucosa nor the control group was observed. Statistically significant very strong and strong correlations were found between genes in the lip and palatine tissue. The expression of FGFR1, FGFR2 and FOXO1 in cleft-affected lip and palatine tissue seems to be highly individual. Numerous intercorrelations between the genes do not exclude their role in the possible complex morphopathogenesis of orofacial clefts.

Quantifying changes in ultrasound tongue-shape pre- and post-intervention in speakers with submucous cleft palate: an illustrative case study

Ultrasound Tongue Imaging is increasingly used during assessment and treatment of speech sound disorders. Recent literature has shown that ultrasound is also useful for the quantitative analysis of a wide range of speech errors. So far, the compensatory articulations of speakers with cleft palate have only been analysed qualitatively. This study provides a pilot quantitative ultrasound analysis, drawing on longitudinal intervention data from a child with submucous cleft palate. Two key ultrasound metrics were used: 1. articulatory t-tests were used to compare tongue-shapes for perceptually collapsed phonemes on a radial measurement grid and 2. the Mean Radial Difference was reported to quantify the extent to which the two tongue shapes differ, overall. This articulatory analysis supplemented impressionistic phonetic transcriptions and identified covert contrasts. Articulatory errors identified in this study using ultrasound were in line with errors identified in the speech of children with cleft palate in previous literature. While compensatory error patterns commonly found in speakers with cleft palate have been argued to facilitate functional phonological development, the nature of our findings suggest that the compensatory articulations uncovered are articulatory in nature.

Outcome of the 'waiting until spontaneous extrusion' strategy for long-term tympanostomy tube placement in children with cleft palate

BACKGROUND

Otitis media with effusion (OME) in children with cleft palate (CP) is known to be refractory to treatment and most of these patients undergo surgery for ventilation tube (VT) placement.

OBJECTIVES

To identify the outcomes of children with CP using long-term VT with a 'waiting until spontaneous extrusion' strategy.

MATERIAL AND METHODS

We retrospectively reviewed the medical records of all children with CP who visited our department from December 2016 to November 2017 and who received long-term VT placement in our department. Risk factors related to residual perforation and recurrence of OME were analyzed.

RESULTS

A total of 106 children were included in this study. Our statistical analysis of 94 ears followed for more than three months after VT loss revealed that longer VT placement was associated with residual perforation, and shorter VT placement was associated with OME recurrence. Although a longer duration of VT placement was associated with an increased rate, extremely long-term VT placement was not associated with residual perforation, as expected. Half of the VTs were spontaneously extruded at 40 months after insertion.

CONCLUSIONS AND SIGNIFICANCE

Long-term VT insertion using a waiting until spontaneous extrusion strategy is a potential option for children with CP.

Eating and swallowing disorders in children with cleft lip and/or palate

Introduction. Cleft lip and palate are complex congenital anomalies of the orofacial system of children. Feeding and swallowing problems occur with varying degrees in children with cleft lip and/or palate. Aim. The aim of this paper was to review the literature and available evidence regarding the types of eating and swallowing disorders that can be identified in children with cleft lip and/or palate, as well as a description and types of compensatory strategies and interventions to alleviate difficulties. Methods. Insight into the relevant literature was performed by specialized search engines on the internet and insight into the electronic database. Results. The extent of the cleft is related to the severity of eating and swallowing disorders, so the most common problems are decreased oral sensitivity, cough, choking, nasal regurgitation, difficulty in sucking, laryngotracheal aspiration due to inadequate airway protection during swallowing, which may result in pneumonia and lung damage. Feeding and swallowing difficulty is also a source of stress for parents. Conclusion. Choking, coughing, nasal regurgitation, laryngotracheal aspiration, excessive air intake can lead to dehydration, malnutrition, but also the need for alternative feeding methods Therefore, it is of great importance to identify the problems of feeding and swallowing in a timely manner, along with modifications of the feeding method.

Association Between SNPs in 1q32.2 and NSCL ± P in Han Chinese Population

OBJECTIVES

Non-syndromic cleft lip with or without cleft palate (NSCL ± P) is one of the most common birth malformations. Currently, numerous susceptibility SNPs have been reported by GWA studies, however, the replications of them among NSCL ± P from Han Chinese were very limited.

DESIGN

In this study, we selected 16 SNPs around 1q32.2 based on the published GWA studies and replicated them among 302 trios with NSCL ± P from Han Chinese Population. The genotypic data was analyzed with FBAT, PLINK and R package.

SETTING

The study was conducted in a tertiary medical center.

PATIENTS, PARTICIPANTS

302 patients with CL ± P and their parents.

MAIN OUTCOME MEASURES

To ascertain the genetic variants in 1q32.2 in patients with CL ± P in Han Chinese Population.

INTERVENTIONS

Blood samples were collected.

RESULTS

We found T allele (Z = 4.26, p = 0.00002) and T/T homozygotes (Z = 4.4, p = 0.000011) at rs12063989 was significantly over-transmitted among non-syndromic cleft lip with or without cleft palate (NSCL ± P).

CONCLUSIONS

We found rs12063989 exhibited significant association with the occurrence of NSCL ± P, which would provide new evidence for the future study in the etiology of NSCL ± P.

Genome-wide Gene-by-Sex Interaction Studies Identify Novel Nonsyndromic Orofacial Clefts Risk Locus

Risk loci identified through genome-wide association studies have explained about 25% of the phenotypic variations in nonsyndromic orofacial clefts (nsOFCs) on the liability scale. Despite the notable sex differences in the incidences of the different cleft types, investigation of loci for sex-specific effects has been understudied. To explore the sex-specific effects in genetic etiology of nsOFCs, we conducted a genome-wide gene × sex (GxSex) interaction study in a sub-Saharan African orofacial cleft cohort. The sample included 1,019 nonsyndromic orofacial cleft cases (814 cleft lip with or without cleft palate and 205 cleft palate only) and 2,159 controls recruited from 3 sites (Ethiopia, Ghana, and Nigeria). An additive logistic model was used to examine the joint effects of the genotype and GxSex interaction. Furthermore, we examined loci with suggestive significance (P < 1E-5) in the additive model for the effect of the GxSex interaction only. We identified a novel risk locus on chromosome 8p22 with genome-wide significant joint and GxSex interaction effects (rs2720555, p_2df = 1.16E-08, p_GxSex = 1.49E-09, odds ratio [OR] = 0.44, 95% CI = 0.34 to 0.57). For males, the risk of cleft lip with or without cleft palate at this locus decreases with additional copies of the minor allele (p < 0.0001, OR = 0.60, 95% CI = 0.48 to 0.74), but the effect is reversed for females (p = 0.0004, OR = 1.36, 95% CI = 1.15 to 1.60). We replicated the female-specific effect of this locus in an independent cohort (p = 0.037, OR = 1.30, 95% CI = 1.02 to 1.65), but no significant effect was found for the males (p = 0.29, OR = 0.86, 95% CI = 0.65 to 1.14). This locus is in topologically associating domain with craniofacially expressed and enriched genes during embryonic development. Rare coding mutations of some of these genes were identified in nsOFC cohorts through whole exome sequencing analysis. Our study is additional proof that genome-wide GxSex interaction analysis provides an opportunity for novel findings of loci and genes that contribute to the risk of nsOFCs.

Comparative clinical evaluation of modified and conventional Grayson's presurgical nasoalveolar molding technique in infants with complete unilateral cleft lip and palate

BACKGROUND

Presurgical nasoalveolar molding (PNAM) was introduced by Grayson et al., in 1993 to presurgically mold the alveolus, lip, and nose in infants with cleft lip and palate (CLP). The aim of this comparative clinical trial was to evaluate the efficacy and efficiency of Modified and Conventional Grayson's PNAM in patients concerning morphological and anatomical changes in maxillary alveolus, nasal symmetry, number of visits, and duration of treatment.

MATERIALS AND METHODS

In this comparative clinical trial study, 16 infants with unilateral complete CLP were equally divided into two groups: Group I (modified PNAM technique using titanium molybdenum alloy [TMA] wire nasal stent) and Group II (conventional PNAM technique using stainless steel wire nasal stent). Patient photographic evaluation of nasal symmetry and maxillary study model CAD-CAM analysis, pre- and post-operatively in both groups, were compared using a paired t-test between the groups using the Chi-square test with P < 0.05 as statistically significant.

RESULTS

In both groups, on evaluating nasal measurements, statistically significant (P < 0.05) decrease in nasal width and increase in columella deviation angle, a decrease of nostril length, and an increase of columella length in Group I were observed. On maxillary study model evaluation, a statistically significant (P < 0.05) decrease in width of the alveolar cleft was noticed in both groups and lateral deviation of the incisal point in Group I and width of the palatal cleft in Group II was noticed.

CONCLUSION

This study showed a morphological improvement in nasal symmetry and maxillary alveolar morphology in complete unilateral CLP patients, treated with both Modified and Conventional PNAM techniques, with the Modified PNAM technique being more efficient for treatment duration and the number of adjustments as there are less number of visits.

Maternal exposure to sulfur dioxide and the risk of oral clefts in Liaoning Province, China: a population-based case-control study

There is limited and equivocal epidemiological evidence relating to the association between maternal sulfur dioxide (SO₂) exposure and the risk of oral clefts (OCs) in offspring. We performed a population-based case-control study in Liaoning province to evaluate aforementioned relationship during 3 months before conception, the first trimester of pregnancy, and their single months. The study involved 3086 patients with OCs and 7950 controls. Data relating to SO₂ concentration was acquired from air monitoring stations throughout the study period. We used a multivariable logistic regression model to evaluate the association between exposure to SO₂ and the risk of OCs during the exposure windows. Maternal SO₂ exposure was positively related to OCs during the 3 months before conception (odds ratio = 1.38, 95% confidence interval: 1.15-1.65; P for trend < 0.01). Positive relationships were obtained from the first and second months before conception and the first month of pregnancy. Thus, our research reflects a relationship between SO₂ exposure and the risk of OCs. Future studies are now required to verify the association between SO₂ exposure and OCs during pregnancy and indicate the most relevant vulnerable exposure time windows.

Pleiotropy method reveals genetic overlap between orofacial clefts at multiple novel loci from GWAS of multi-ethnic trios

Based on epidemiologic and embryologic patterns, nonsyndromic orofacial clefts- the most common craniofacial birth defects in humans- are commonly categorized into cleft lip with or without cleft palate (CL/P) and cleft palate alone (CP), which are traditionally considered to be etiologically distinct. However, some evidence of shared genetic risk in IRF6, GRHL3 and ARHGAP29 regions exists; only FOXE1 has been recognized as significantly associated with both CL/P and CP in genome-wide association studies (GWAS). We used a new statistical approach, PLACO (pleiotropic analysis under composite null), on a combined multi-ethnic GWAS of 2,771 CL/P and 611 CP case-parent trios. At the genome-wide significance threshold of 5 × 10-8, PLACO identified 1 locus in 1q32.2 (IRF6) that appears to increase risk for one OFC subgroup but decrease risk for the other. At a suggestive significance threshold of 10-6, we found 5 more loci with compelling candidate genes having opposite effects on CL/P and CP: 1p36.13 (PAX7), 3q29 (DLG1), 4p13 (LIMCH1), 4q21.1 (SHROOM3) and 17q22 (NOG). Additionally, we replicated the recognized shared locus 9q22.33 (FOXE1), and identified 2 loci in 19p13.12 (RAB8A) and 20q12 (MAFB) that appear to influence risk of both CL/P and CP in the same direction. We found locus-specific effects may vary by racial/ethnic group at these regions of genetic overlap, and failed to find evidence of sex-specific differences. We confirmed shared etiology of the two OFC subtypes comprising CL/P, and additionally found suggestive evidence of differences in their pathogenesis at 2 loci of genetic overlap. Our novel findings include 6 new loci of genetic overlap between CL/P and CP; 3 new loci between pairwise OFC subtypes; and 4 loci not previously implicated in OFCs. Our in-silico validation showed PLACO is robust to subtype-specific effects, and can achieve massive power gains over existing approaches for identifying genetic overlap between disease subtypes. In summary, we found suggestive evidence for new genetic regions and confirmed some recognized OFC genes either exerting shared risk or with opposite effects on risk to OFC subtypes.

Family history in non-syndromic orofacial clefts: Is there a pattern?

OBJECTIVE

To survey the frequency and pattern of family history for non-syndromic orofacial clefts (NSOFC). Initial hypothesis: more complex forms have a higher frequency of positive family history.

MATERIALS AND METHODS

A retrospective study was carried with 2,668 subjects with three different types of clefts (CL Group (cleft lip), CLP Group (cleft lip and palate), and CP group (cleft palate)); family history information was collected. The Chi-square (X² ) and Z-test were used.

RESULTS

A positive family history was found in 31% of the sample. The CLP Group had highest percentage and highest proportion of affected relatives, being these factors statistically significant when compared to the CP Group. Comparisons between the CLP Male and CL Male with CP Male were statistically significant. First-degree kinship was the most frequently found.

CONCLUSIONS

The initial hypothesis was confirmed, subjects with CLP had the highest percentage of positive family history, the highest proportion of affected relatives and had more affected relatives in comparison with CP. It is more common to find affected relatives in the CLP Male and CL Male groups when compared with CP Male. CLP and CP groups present a pattern of occurrence of the type of cleft in the family.

FAT4 identified as a potential modifier of orofacial cleft laterality

Orofacial clefts (OFCs) are common (1 in 700 births) congenital malformations that include a cleft lip (CL) and cleft lip and palate (CLP). These OFC subtypes are also heterogeneous themselves, with the CL occurring on the left, right, or both sides of the upper lip. Unilateral CL and CLP have a 2:1 bias towards left-sided clefts, suggesting a nonrandom process. Here, we performed a study of left- and right-sided clefts within the CL and CLP subtypes to better understand the genetic factors controlling cleft laterality. We conducted genome-wide modifier analyses by comparing cases that had right unilateral CL (RCL; N = 130), left unilateral CL (LCL; N = 216), right unilateral CLP (RCLP; N = 416), or left unilateral CLP (LCLP; N = 638), and identified a candidate region on 4q28, 400 kb downstream from FAT4, that approached genome-wide significance for LCL versus RCL (p = 8.4 × 10^-8 ). Consistent with its potential involvement as a genetic modifier of CL, we found that Fat4 exhibits a specific domain of expression in the mesenchyme of the medial nasal processes that form the median upper lip. Overall, these results suggest that the epidemiological similarities in left- to right-sided clefts in CL and CLP are not reflected in the genetic association results.

Wavelet Screening identifies regions highly enriched for differentially methylated loci for orofacial clefts

DNA methylation is the most widely studied epigenetic mark in humans and plays an essential role in normal biological processes as well as in disease development. More focus has recently been placed on understanding functional aspects of methylation, prompting the development of methods to investigate the relationship between heterogeneity in methylation patterns and disease risk. However, most of these methods are limited in that they use simplified models that may rely on arbitrarily chosen parameters, they can only detect differentially methylated regions (DMRs) one at a time, or they are computationally intensive. To address these shortcomings, we present a wavelet-based method called 'Wavelet Screening' (WS) that can perform an epigenome-wide association study (EWAS) of thousands of individuals on a single CPU in only a matter of hours. By detecting multiple DMRs located near each other, WS identifies more complex patterns that can differentiate between different methylation profiles. We performed an extensive set of simulations to demonstrate the robustness and high power of WS, before applying it to a previously published EWAS dataset of orofacial clefts (OFCs). WS identified 82 associated regions containing several known genes and loci for OFCs, while other findings are novel and warrant replication in other OFCs cohorts.

Craniofacial Growth Analysis of Individuals With and Without Cleft Lip and Palate in Colombia

INTRODUCTION

Craniofacial growth is a dynamic and unpredictable process influenced by genetic and environmental factors, presenting phenotypic and gender differences.

OBJECTIVE

Evaluate the differences in craniofacial growth and development in a group of Colombian individuals with complete unilateral and bilateral cleft lip and palate (CLP) and without CLP, classified by gender and age.

SETTING AND SAMPLE POPULATION

Five hundred forty-one profile radiographs of 126 patients with unilateral CLP, 126 with bilateral CLP, and 289 without CLP. All patients of affected groups had a history of CLP correction surgery without nasoalveolar molding with orthopedic and orthodontic treatments.

MATERIALS AND METHODS

This cross-sectional study was performed comparing 8 cephalometric measurements on radiographs, 5 linear/3 angular. Analysis was performed by median and interquartile range for all cephalometric measurements. Comparison between the groups was performed using Kruskal-Wallis and Mann-Whitney U, with a 95% confidence.

RESULTS

Significant differences between the groups of patients with and without CLP, between types of clefts and genders. The skeletal structures of patients with CLP were smaller than those of control but improved with growth. Patients with unilateral CLP presented flat profiles and predominant class III malocclusions, while patients with bilateral CLP, at early ages, were class II and in the prepubertal stage, the values were progressively negative until the end of the growth period, suggesting class III. Patients with CLP presented posteroinferior rotation of the mandible, vertical measurements increased, and deflection of the cranial base.

CONCLUSION

Given their growth alterations, patients with CLP benefit from orthopedic and orthodontic treatment.

Parental Risk Factors and Child Birth Data in a Matched Year and Sex Group Cleft Population: A Case-Control Study

(1) Background: The etiology of orofacial cleft (OC) is not completely known but several genetic and environmental risk factors have been identified. Moreover, a knowledge gap still persists regarding neonatal characteristics. This study evaluated the effect of parental age and mothers’ body mass index on the risk of having an OC child, in a matched year and sex group (cleft/healthy control). Additionally, birth data were analyzed between groups. (2) Methods: 266 individuals born between 1995 to 2015 were evaluated: 133 OC individuals (85 males/48 females) and 133 control (85 males/48 females). A logistic model was used for the independent variables. ANOVA or Kruskal-Wallis tests were used for comparison between the OC phenotypes. (3) Results: Regarding statistically significant parental related factors, the probability of having a cleft child decreases for each maternal year increase (odds ratio = 0.903) and increases for each body mass index unit (kg/m²) increase (odds ratio = 1.14). On the child data birth, for each mass unit (kg) increase, the probability of having a cleft child decrease (odds ratio = 0.435). (4) Conclusions: In this study, only maternal body mass index and maternal age found statistical differences in the risk of having a cleft child. In the children’s initial data, the cleft group found a higher risk of having a lower birth weight but no relation was found regarding length and head circumference.

Altered regulation of cell migration in IRF6-mutated orofacial cleft patients-derived primary cells reveals a novel role of Rho GTPases in cleft/lip palate development

Orofacial clefts are the most common congenital craniofacial birth defects. They occur from a failure in cell proliferation and fusion of neural crest cells of the lip buds and/or palatal shelves. In this study, we investigate the genetic basis and molecular mechanisms in primary cells derived from a cleft and lip palate patient presenting van der Woude syndrome (VWS). Since mutations in the integrin genes are widely correlated with VWS, Interferon Regulatory Factor 6 (IRF6) screening was conducted in a cohort of 200 participants presenting with orofacial anomalies. Primary fibroblastic cells derived from the upper right gingiva and palatal regions were isolated and two cellular populations from two participants were obtained: a control with no cleft phenotype and a patient with a cleft phenotype typical of van der Woude syndrome (VWS). IRF6 targeted sequencing revealed mutations in two distinct families. Our results showed no alteration in the viability of the CLP/VWS patient cells, suggesting the phenotype associate with the disease is not secondary to a defect in cell proliferation. We did however detect a significant decrease in the migratory ability of the CLP with Van der Woude syndrome (CLP/VWS) patient cells, which could account for the phenotype. When compared to normal cells, patient cells showed a lack of polarization, which would account for their lack of mobility. Patient cells showed protrusions all around the cells and a lack of defined leading edge. This was reflected with actin staining, WAVE2 and Arp2 around the cell, and correlated with an increase in Rac1 activation. Consistently with the increase in Rac1 activation, patient cells showed a loss in the maturation of focal adhesions needed for contractility, which also accounts for the lack in cell migration. Our findings give increased understanding of the molecular mechanisms of VWS and expands the knowledge of van der Woude syndrome (VWS) occurrence by providing a strong molecular evidence that CLP with Van der Woude syndrome (CLP/VWS) phenotype is caused by a defect in normal physiological processes of cells.