Nonsyndromic Cleft Research Articles

Quality of Life among Youths having Repaired Non-syndromic Cleft Lip and Palate in Karachi

Abstract
 Objective: To compare general quality of life of youths having repaired non-syndromic CLP with controls using a generic quality of life instrument, Youth Quality of Life – Research Version (YQOL-R).
 Methods: case control study was conducted from January, 2017 to December, 2018. Inclusion criteria was patients having repaired non syndromic Cleft Lip and Palate, age 15 to 29 years, of either gender while controls were healthy individuals of similar age. Quality of life was measured using validated YQOL-R instrument. Data of 62 cases and 107 healthy controls, consented for study was analysed using statistical software, SPSS version 20.
 Results:. Mean age was 22.09+5.04. Cronbach’s alpha for domains of sense of self was 0.630, relationship domain (0.795), environmental domain (0.826) and general quality of life domain was 0.688 and for YQOL-R was 0.866. Significant difference was observed for self care domain (63.10 vs. 73.50; p-value = 0.001), relationship domain (79.5 vs. 83.73; p-value = 0.013), environmental domain (70.89 vs. 84.60; p-value = 0.001), general quality of life domain (79.80 vs. 86.04; p-value = 0.012) and percent score of total perceptual score between cases and controls (73.32 vs. 81.97; p-value = 0.001). 
 Conclusion: Compared to cases healthy controls had a better quality of life as they have significantly better results in self care, relationship, environment and general quality of life domains along with mean perceptual percentage.

Genetic and epigenetic studies in non-syndromic oral clefts.

The etiology of non-syndromic oral clefts (NSOFC) is complex with genetics, genomics, epigenetics, and stochastics factors playing a role. Several approaches have been applied to understand the etiology of non-syndromic oral clefts. These include linkage, candidate gene association studies, genome-wide association studies, whole-genome sequencing, copy number variations, and epigenetics. In this review, we shared these approaches, genes, and loci reported in some studies.

IRF6 rs2235371 as a risk factor for non-syndromic cleft palate only among the Deutero-Malay race in Indonesia and its effect on the IRF6 mRNA expression level.

During the early embryological development of the face, complex orofacial failure results in a non-syndromic cleft lip and palate (NS CLP). The interferon regulatory factor 6 gene (IRF6) rs2235371 is a non-synonymous polymorphism that is one of the strong candidate genes associated with NS CLP. The purpose of this study was to determine IRF6 rs2235371 as a risk factor for NS CLP and its phenotypes, including complete unilateral cleft lip and palate (CUCLP), bilateral cleft lip and palate (BCLP), cleft lip only (CL), and cleft palate only (CP), as well as to examine the effect of the polymorphism on the IRF6 mRNA expression levels among the Deutero-Malay race in Indonesia. This study used a case-control design and enrolled 264 samples, including 158 NS CLP cases (42 NS CUCLP, 34 NS BCLP, 33 NS CL, and 49 NS CP) and 106 control subjects. DNA was extracted from venous blood, and then subjected to polymerase chain reaction (PCR) and sequencing. The odds ratio (OR) was used to determine the risk factor for NS CLP and its phenotypes. The Livak, KruskalWallis and Mann-Whitney U tests were used to determine mRNA expression levels in the oral epithelium, followed by real-time quantitative PCR (RT-qPCR). Among all of the NS CLP cases, in the NS CP phenotype, OR for the A mutant allele and the GA genotype was 2,492 (p = 0.017) and 2,114 (p = 0.048), respectively. The IRF6 mRNA expression level of the GA genotype was higher in the NS CP subjects as compared to the GG genotype (p = 0.031). The IRF6 rs2235371 polymorphism is associated with the NS CP phenotype in DeuteroMalay patients from Indonesia and it affects the IRF6 mRNA expression level.

Genome-wide association study of multiethnic nonsyndromic orofacial cleft families identifies novel loci specific to family and phenotypic subtypes.

Nonsyndromic orofacial clefts(OFCs) are among the most common craniofacial birth defects worldwide, and known to exhibit phenotypic and genetic heterogeneity. Cleft lip plus cleft palate (CLP) and cleft lip only (CL) are commonly combined together as one phenotype (CL/P), separately from cleft palate alone. In comparison, our study analyzes CL and CLP separately. A sample of 2218 CL and CLP cases, 4537 unaffected relatives of cases, and 2673 pure controls with no family history of OFC were selected from the Pittsburgh Orofacial Cleft (Pitt-OFC) multiethnic study.genome-wide association studieswere run for seven specific phenotypes created based on the cleft type(s) observed within these families, as well as the combined CL/P phenotype. Five novel genome-wide significant associations, 3q29 (rs62284390), 5p13.2 (rs609659), 7q22.1 (rs6465810), 19p13.3 (rs628271), and 20q13.33 (rs2427238), and nine associations (p ≤ 1.0E-05) within previously confirmed OFC loci-PAX7, IRF6, FAM49A, DCAF4L2, 8q24.21, ARID3B, NTN1, TANC2 and the WNT9B:WNT3 gene cluster-were observed. We also found that single nucleotide polymorphisms within a subset of the associated loci, both previously known and novel, differ substantially in terms of their effects across cleft- or family-specific phenotypes, indicating not only etiologic differences between CL and CLP, but also genetic heterogeneity within each of the two OFC subtypes.

Pathway analysis identified a significant association between cell-cell adherens junctions-related genes and non-syndromic cleft lip/palate in 895 Asian case-parent trios

ObjectivesTo study the association between the seven cell-cell adherens junctions (AJs) -related genes (CDH1, CTNND1, CTNNA1, ESRP1, ESRP2, PLEKHA5, and PLEKHA7) and non-syndromic cleft lip with or without cleft palate (NSCL/P) in the Asian population. DesignThe study included 895 NSCL/P case-parent trios of Asian ethnicity drawn from an international consortium established for a genome-wide association study. We performed association analysis by applying the genotypic transmission disequilibrium test for each of the 144 single nucleotide polymorphisms (SNPs), the versatile gene-based association study for the combined effects of all SNPs, all in or around the seven target genes, and the versatile pathway-based approach for the combined effects of these seven target genes, consecutively. ResultsIn our analysis, we found neither a significant SNP-based nor gene-based association with NSCL/P for any of the 144 relevant SNPs or the seven target genes. However, novel evidence of a significant association (P = 6.00 × 10−6) with NSCL/P was observed in the combined effects of these seven target genes in the versatile pathway-based analysis. ConclusionsOur results were consistent with the findings of previously published human sequencing studies and reinforced the role of these cell-cell AJs-related genes in the pathogenesis of NSCL/P that may be replicated using data from other genome-wide association studies. This pathway approach better reflects our current understanding of the biological mechanisms underlying the aetiology of NSCL/P.

The Public Health Importance of Flaviviruses as an Etiological Environmental Factor in Nonsyndromic Cleft Lip and/or Palate: In silico Study.

This in silico study aims to investigate flaviviruses as an environmental factor in the etiology of nonsyndromic cleft lip and/or palate (CL/P). A scoring method with 7 topics—disease, transplacental passage, tropism, cellular damage, reported case, analysis of genome similarity, and transcriptome between virus and host, was created based on literature and in silico experimentation. Viral genomes of NCBI virus were obtained and BLAST 2.12.0 was applied for the similarity analysis, adjusted to search for only human sequences related to CL/P with the statistical threshold defined for E-value ≤1. Flaviviruses with high potential to cause CL/P were: serotypes 2, 3, and 4 of the Dengue virus and lineage 2 of the West Nile virus, while the Yellow Fever virus, Japanese encephalitis virus, Tick-borne encephalitis virus, and Saint Louis encephalitis virus presented with medium potential to cause CL/P. As for the Zika virus, even strains associated with microcephaly showed only medium potential. Dengue virus and West Nile virus presented with high potential to act as environmental factors in the etiology of CL/P.

Polygenic risk impacts PDGFRA mutation penetrance in non-syndromic cleft lip and palate.

Non-syndromic cleft lip with or without cleft palate (NSCL/P) is a common, severe craniofacial malformation that imposes significant medical, psychosocial and financial burdens. NSCL/P is a multifactorial disorder with genetic and environmental factors playing etiologic roles. Currently, only 25% of the genetic variation underlying NSCL/P has been identified by linkage, candidate gene and genome-wide association studies. In this study, whole-genome sequencing and genome-wide genotyping followed by polygenic risk score (PRS) and linkage analyses were used to identify the genetic etiology of NSCL/P in a large three-generation family. We identified a rare missense variant in PDGFRA (c.C2740T; p.R914W) as potentially etiologic in a gene-based association test using pVAAST (P = 1.78×10-4) and showed decreased penetrance. PRS analysis suggested that variant penetrance was likely modified by common NSCL/P risk variants, with lower scores found among unaffected carriers. Linkage analysis provided additional support for PRS-modified penetrance, with a 7.4-fold increase in likelihood after conditioning on PRS. Functional characterization experiments showed that the putatively causal variant was null for signaling activity in vitro; further, perturbation of pdgfra in zebrafish embryos resulted in unilateral orofacial clefting. Our findings show that a rare PDGFRA variant, modified by additional common NSCL/P risk variants, have a profound effect on NSCL/P risk. These data provide compelling evidence for multifactorial inheritance long postulated to underlie NSCL/P and may explain some unusual familial patterns.

Genome-wide Interaction Study Implicates VGLL2 and Alcohol Exposure and PRL and Smoking in Orofacial Cleft Risk.

Non-syndromic cleft lip with or without cleft palate (NSCL/P) is a common birth defect, affecting approximately 1 in 700 births. NSCL/P has complex etiology including several known genes and environmental factors; however, known genetic risk variants only account for a small fraction of the heritability of NSCL/P. It is commonly suggested that gene-by-environment (G×E) interactions may help explain some of the “missing” heritability of NSCL/P. We conducted a genome-wide G×E interaction study in cases and controls of European ancestry with three common maternal exposures during pregnancy: alcohol, smoking, and vitamin use using a two-stage design. After selecting 127 loci with suggestive 2df tests for gene and G x E effects, 40 loci showed significant G x E effects after correcting for multiple tests. Notable interactions included SNPs of 6q22 near VGLL2 with alcohol and 6p22.3 near PRL with smoking. These interactions could provide new insights into the etiology of CL/P and new opportunities to modify risk through behavioral changes.

Targeted Re-Sequencing of the 2p21 Locus Identifies Non-Syndromic Cleft Lip Only Novel Susceptibility Gene ZFP36L2.

rs7590268 present on the 2p21 locus was identified to be associated with non-syndromic cleft lip with or without cleft palate (NSCL/P) in several populations, including the Chinese Han population, indicating that 2p21 was a susceptibility locus for NSCL/P. However, previous studies have only identified common single-nucleotide polymorphism (SNP) within the THADA gene, neglecting the rare variants and other genes in 2p21; thus, this study was designed to investigate additional variants and novel susceptibility genes in 2p21. A total of 159 NSCL/P patients and 542 controls were recruited in the discovery phase, whereas 1830 NSCL/P patients and 2,436 controls were recruited in the replication phase. After targeted region sequencing, we performed association and burden analyses for the common and rare variants, respectively. Furthermore, RNA-seq, proliferation assay and cell cycle analysis were performed to clarify the possible function of the candidate gene ZFP36L2. Association analysis showed that four SNPs were specifically associated with non-syndromic cleft lip only (NSCLO) and two SNPs were associated with both NSCLO and NSCL/P. Burden analysis indicated that ZFP36L2 was associated with NSCLO (p = .0489, OR = 2.41, 95% CI: 0.98–5.90). Moreover, SNPs in the ZFP36L2 targeted gene JUP were also associated with NSCLO. ZFP36L2 also inhibited cell proliferation and induced G2 phase arrest in the GMSM-K cell line. Therefore, we proposed that ZFP36L2 is a novel susceptibility gene of NSCLO in the 2p21 locus, which could lead to NSCLO by modulating cell proliferation and cycle.

Evaluation of genome-wide association signals for nonsyndromic cleft lip with or without cleft palate in a multiethnic Brazilian population

ObjectiveTo evaluate previous nonsyndromic cleft lip with or without cleft palate (NSCL±P) associated signals in 4p16.2, 8p11.23, 12q13.13, 12q13.2 and 17q21.32 in a multiethnic Brazilian cohort. DesignThe single nucleotide polymorphisms (SNPs) rs34246903 in 4p16.2, rs13317 in 8p11.23 (FGFR1, fibroblast growth factor receptor 1), rs3741442 in 12q13.13, rs705704 in 12q13.2 and rs4968247 in 17q21.32 were genotyped with TaqMan allelic discrimination assays in a case-control sample including 801 NSCL±P patients [233 nonsyndromic cleft lip (NSCLO) and 568 nonsyndromic cleft lip and palate (NSCLP)] and 881 healthy controls. Multiple logistic regression analyses, considering sex and genomic ancestry as covariates, were conducted, and the p value was adjusted with Bonferroni multiple correction testing (p ≤ 0.01). ResultsAlthough several associations were identified, those that resisted the multiple correction testing involved the alleles and genotypes of rs34246903 and rs13317. The NSCLO group had a lower frequency of the minor C allele of rs34246903 compared to controls, giving an odds ratio (OR) of 0.74 [95% confidence interval (CI): 0.59–0.93, p = 0.01]. The rs34246903 CC genotype (homozygous) and the recessive model revealed significant protective associations with NSCLO, yielding ORs of 0.50 (95% CI: 0.29–0.85, p = 0.005) and 0.55 (95% CI: 0.33–0.93, p = 0.01) respectively. The presence of C variant allele of rs13317 (OR: 0.81, 95% CI: 0.69–0.96, p = 0.01) as well the TC genotype (OR: 0.77, 95% CI: 0.62–0.94, p = 0.01) and the dominant model (OR: 0.77, 95% CI: 0.63–0.94, p = 0.009) showed significant associations with reduced risk of NSCL±P. ConclusionOur study is the first to support the association of rs34246903 (4p16.2) with NSCLO and rs13317 within FGFR1 with NSCL±P in the highly admixed Brazilian population. Further studies are needed to determine the functionality of those SNPs or to identify the causal markers in linkage disequilibrium with those susceptibility markers.

Allele-specific transcription factor binding in a cellular model of orofacial clefting

Non-syndromic cleft lip with/without cleft palate (nsCL/P) is a frequent congenital malformation with multifactorial etiology. While recent genome-wide association studies (GWAS) have identified several nsCL/P risk loci, the functional effects of the associated non-coding variants are largely unknown. Furthermore, additional risk loci remain undetected due to lack of power. As genetic variants might alter binding of transcription factors (TF), we here hypothesized that the integration of data from TF binding sites, expression analyses and nsCL/P GWAS might help to (i) identify functionally relevant variants at GWAS loci, and (ii) highlight novel risk variants that have been previously undetected. Analysing the craniofacial TF TFAP2A in human embryonic palatal mesenchyme (HEPM) cells, we identified 2845 TFAP2A ChIP-seq peaks, several of which were located near nsCL/P candidate genes (e.g. MSX1 and SPRY2). Comparison with independent data suggest that 802 of them might be specific to craniofacial development, and genes near these peaks are enriched in processes relevant to nsCL/P. Integration with nsCL/P GWAS data, however, did not show robust evidence for co-localization of common nsCL/P risk variants with TFAP2A ChIP-seq peaks. This data set represents a new resource for the analyses of craniofacial processes, and similar approaches with additional cell lines and TFs could be applied to generate further insights into nsCL/P etiology.

Random Network and Non-rich-club Organization Tendency in Children With Non-syndromic Cleft Lip and Palate After Articulation Rehabilitation: A Diffusion Study.

ObjectiveThe neuroimaging pattern in brain networks after articulation rehabilitation can be detected using graph theory and multivariate pattern analysis (MVPA). In this study, we hypothesized that the characteristics of the topology pattern of brain structural network in articulation-rehabilitated children with non-syndromic cleft lip and palate (NSCLP) were similar to that in healthy comparisons.MethodsA total of 28 children with NSCLP and 28 controls with typical development were scanned for diffusion tensor imaging on a 3T MRI scanner. Structural networks were constructed, and their topological properties were obtained. Besides, the Chinese language clear degree scale (CLCDS) scores were used for correlation analysis with topological features in patients with NSCLP.ResultsThe NSCLP group showed a similar rich-club connection pattern, but decreased small-world index, normalized rich-club coefficient, and increased connectivity strength of connections compared to controls. The univariate and multivariate patterns of the structural network in articulation-rehabilitated children were primarily in the feeder and local connections, covering sensorimotor, visual, frontoparietal, default mode, salience, and language networks, and orbitofrontal cortex. In addition, the connections that were significantly correlated with the CLCDS scores, as well as the weighted regions for classification, were chiefly distributed in the dorsal and ventral stream associated with the language networks of the non-dominant hemisphere.ConclusionThe average level rich-club connection pattern and the compensatory of the feeder and local connections mainly covering language networks may be related to the CLCDS in articulation-rehabilitated children with NSCLP. However, the patterns of small-world and rich-club structural organization in the articulation-rehabilitated children exhibited a random network and non-rich-club organization tendency. These findings enhanced the understanding of neuroimaging patterns in children with NSCLP after articulation rehabilitation.

Association of Single-Nucleotide Polymorphisms of MAFB Gene with Nonsyndromic Cleft Lip with or without Cleft Palate in Kinh Vietnamese Patients.

Background Cleft lip with or without palate (CL/P) is the most common orofacial birth defect. Single-nucleotide polymorphisms (SNPs) in MAFB gene (V-Maf avian musculoaponeurotic fibrosarcoma oncogene homolog B) were identified as susceptible to this defect in a genome-wide association study. To further evaluate its role in this birth defect, we conducted this study with the aim of identifying allele frequencies, genotype frequencies, and association of SNPs rs13041247, rs6065259, and rs6072081 of MAFB gene with nonsyndromic cleft lip/palate (NCL/P) in Kinh Vietnamese patients. Methods We performed case–control study involved 79 patients with NCL/P and 77 healthy controls. DNAs were extracted from participants' saliva and tetra-amplification refractory mutation system polymerase chain reaction (tetra-ARMS PCR) was used for genotyping SNPs. Results SNPs of MAFB gene were genotyped using the Tetra-ARMS PCR method. We found that genotype CT of rs13041247 was associated with an increased risk of NCL/P in Kinh Vietnamese (odds ratio TCTT [OR TC/TT ] = 1.63, 95% confidence interval [CI] = 0.83–3.19, p = 0.17). The G allele genotypes of SNP rs6072081 increase high risk for the malformation, statistically significant result (OR GG/AA = 7.06, 95% CI = 2.13–23.42, p < 0.001). There is no clear association between rs6065259 and CL/P (OR AA/GG = 0.75, 95% CI = 0.22–2.50, p = 0.32; OR AG/GG = 1.53, 95% CI = 0.79–2.97, p = 0.32). When the patients were divided into the phenotypic subgroups, there was a similar significant trend between the patients and controls for all SNPs. Conclusions Our study provides further evidence of role of MAFB gene variations with NCL/P defect in Kinh Vietnamese.

Genetic markers for non-syndromic orofacial clefts in populations of European ancestry: a meta-analysis

To date, the involvement of various genetic markers in the aetiopathogenesis of non-syndromic orofacial cleft (nsOFC) has been extensively studied. In the present study, we focused on studies performed on populations of European ancestry to systematically review the available literature to define relevant genetic risk factors for nsOFC. Eligible studies were obtained by searching Ovid Medline and Ovid Embase. We gathered the genetic markers from population-based case–control studies on nsOFC, and conducted meta-analysis on the repeatedly reported markers. Whenever possible, we performed stratified analysis based on different nsOFC phenotypes, using allelic, dominant, recessive and overdominant genetic models. Effect sizes were expressed as pooled odds ratios (ORs) with 95% confidence intervals (CIs), and p ≤ 0.05 were considered statistically significant. A total of 84 studies were eligible for this systematic review, with > 700 markers included. Of these, 43 studies were included in the meta-analysis. We analysed 47 genetic variants in 30 genes/loci, which resulted in 226 forest plots. There were statistically significant associations between at least one of the nsOFC phenotypes and 19 genetic variants in 13 genes/loci. These data suggest that IRF6, GRHL3, 8q24, VAX1, TGFA, FOXE1, ABCA4, NOG, GREM1, AXIN2, DVL2, WNT3A and WNT5A have high potential as biomarkers of nsOFC in populations of European descent. Although other meta-analyses that included European samples have been performed on a limited number of genetic variants, this study represents the first meta-analysis of all genetic markers that have been studied in connection with nsOFC in populations of European ancestry.

Labial Vestibular Flap Closure of the Cleft Palate Is Advantageous for Maxillary Development.

Objective: Using labial vestibular flap was performed to close the primary alveolar and hard palate cleft at the second stage of early 2-stage closure surgery for unilateral cleft lip and palate for minimizing the damage to the maxillary periosteum. We analyzed maxillary development to clarify the influence of cleft palate surgery. Design: Retrospective longitudinal study in 5 years after primary palatal closure. Setting: Institutional study Patients: Study subjects included 214 patients with nonsyndromic complete unilateral cleft lip and palate who were consecutively treated in our clinic. Main Outcome: We used a 3D dental model scanner to assess maxillary development in patients aged 3 months to 5 years after using either the conventional pushback method (PB) (51 cases) or 2-stage closure (Local palatal flap closure: LF [67 cases] and Labial vestibular flap closure: VF [96 cases]). Results: Comparing the measurement results, the major axis of maxilla, width, intercanine distance, and intermolar distance was significantly larger in the LF group compared to the PB group. After the age of 3, the cleft side of VF group had grown significantly to compare with LF group in width. It was also confirmed that the inserted labial mucosal flap itself grew. Enlargement of the labial mucosal flap was observed at all sites except the canine. Conclusion: Good maxillary growth occurred in the following order: VF groups > LF group > PB group. Poor growth was correlated with the extent of periosteal damage during surgery and the degree of postoperative bone surface exposure.

Factors influencing parental pregnancy decision-making due to fetuses with non-syndromic orofacial clefts: a study of Chinese couples

Background: When a fetus is diagnosed with facial deformities, most Chinese couples choose to terminate the pregnancy. However, these couples commonly regret their decision after the termination of the pregnancy, display a heavier degree of grief, and these feelings persist for a long time. The purpose of this study was to investigate factors that influence parental pregnancy decisions regarding fetuses diagnosed with a non-syndromic orofacial cleft (NSOFC), and to provide the preliminary basis for a formulation of interview outlines useful in further qualitative research in this area. Methods: We collected medical records of 400 couples from the obstetrical units of a women’s hospital in China whose fetuses were diagnosed with Orofacial clefts (OFCs) from January 2013 to July 2019. After excluding those records reporting chromosomal or other abnormalities, 311 cases were included in this study. After univariate analysis, factors that may have affected the parental pregnancy decision were analyzed using binary classification regression analysis. Results: Among the 311 couples, 71.7% (223/311) decided to terminate the pregnancy, whereas 28.3% (88/311) decided to continue. The registered residence, family history of NSOFC, maternal high-risk factors that may lead to the fetus suffering from NSOFC, maternal age, paternal age, doctor’s suggestion, prenatal diagnosis, and first diagnosed gestational week all influenced pregnancy decision makings (p &lt; 0.05). Among these, the registered residence, family history of NSOFC, maternal high-risk factors, maternal age, prenatal diagnosis, and first diagnosed gestational week substantially affected the parental pregnancy decision. Discussion: The couples with registered residence in rural areas, no family history of NSOFC, no maternal high-risk factors, younger maternal age, younger gestational age at first diagnosis are at greater relative risk of pregnancy termination. Prenatal diagnosis is a protective factor.

Duration of presurgical orthodontic treatment in individuals with nonsyndromic oral clefts undergoing orthognathic surgery

Introduction: Evaluating the length of orthodontic-surgical treatment is a key factor to properly inform and guide the patient about the duration of treatment and consequently achieve agreement and adherence to treatment, as well as for health-care institutions that sponsor this type of treatment. Objective: The aim of the present study was to investigate the duration of orthodontic treatment before orthognathic surgery, in patients with nonsyndromic oral clefts, as well as the number of consultations required for that purpose. Materials and Methods: This was an observational, retrospective, descriptive study conducted on data obtained from the patients' medical records. The study analyzed 485 medical records and, after applying the inclusion criteria, the sample included 227 medical records. All data were tabulated in an Excel spreadsheet for calculation of means and standard deviations (SDs), for the time period analyzed. Results: The time for orthodontic preparation was 8.2 years with a range of attendance from 1 to 130 visits and a mean of 37 visits (SD ± 24). Conclusion: The results suggest that there is a longer time than reported in the literature for orthodontic preparation for orthognathic surgery, which could contribute to the increase in total time for orthodontic-surgical treatment.

Mouse models in palate development and orofacial cleft research: Understanding the crucial role and regulation of epithelial integrity in facial and palate morphogenesis.

Cleft lip and cleft palate are common birth defects resulting from genetic and/or environmental perturbations of facial development in utero. Facial morphogenesis commences during early embryogenesis, with cranial neural crest cells interacting with the surface ectoderm to form initially partly separate facial primordia consisting of the medial and lateral nasal prominences, and paired maxillary and mandibular processes. As these facial primordia grow around the primitive oral cavity and merge toward the ventral midline, the surface ectoderm undergoes a critical differentiation step to form an outer layer of flattened and tightly connected periderm cells with a non-stick apical surface that prevents epithelial adhesion. Formation of the upper lip and palate requires spatiotemporally regulated inter-epithelial adhesions and subsequent dissolution of the intervening epithelial seam between the maxillary and medial/lateral nasal processes and between the palatal shelves. Proper regulation of epithelial integrity plays a paramount role during human facial development, as mutations in genes encoding epithelial adhesion molecules and their regulators have been associated with syndromic and non-syndromic orofacial clefts. In this chapter, we summarize mouse genetic studies that have been instrumental in unraveling the mechanisms regulating epithelial integrity and periderm differentiation during facial and palate development. Since proper epithelial integrity also plays crucial roles in wound healing and cancer, understanding the mechanisms regulating epithelial integrity during facial development have direct implications for improvement in clinical care of craniofacial patients.

Oro-facial clefts at a tertiary level hospital of eastern Nepal

Introduction: There are only a few centers providing care to orofacial cleft patients across Nepal. However, no adequate data have been reported regarding the epidemiology, pattern, and association of cleft in children from eastern Nepal. The aim of the study was to study the epidemiological profile of cleft lip palate (CLP) patients reporting to the department of oral and maxillofacial surgery (OMFS) in Dharan, Eastern Nepal. Materials and Methods: Data retrospectively retrieved from the cleft registry in the department of OMFS were tabulated and entered into Microsoft Excel 2000. Data of all the diagnosed nonsyndromic orofacial cleft patients attending BP Koirala Institute of Health Sciences for treatment from August 2011 to August 2017 were used for the analysis. Incompletely filled records and syndromic cases were excluded. Results: Data of 220 orofacial clefts were analyzed which included 119 males and 101 females. Among these children with cleft, only 7 patients had direct family members and 18 patients had distant family members having the same condition. Among patients with CL (n = 151), left-sided CL (n = 85) was a more common presentation. Amongst patients with a cleft of the hard plate (n = 153), bilateral (n = 87) presentation was more common. A similar pattern was observed for cleft alveolus (n = 117) with the left side (n = 60) being common. In clefts affecting the soft palate (n = 192), complete cleft (n = 189) was a more common occurrence than incomplete. The majority of our patients had a CLP (n = 133) with isolated CL being the least commonly seen (n = 18). Conclusion: The majority of our patients had a CLP with isolated CL being the least common. This observation is in concordance with reports from other Caucasian and Asian populations both from developed and developing countries.

Association of rs2013162 and rs2235375 Polymorphisms in IRF6 Gene with Susceptibility to Non-Syndromic Cleft Lip and Palate.

Background:Non-syndromic cleft lip occurs by the interaction of environmental and genetic factors. The purpose of the current study was to analyze the association of Single Nucleotide Polymorphisms (SNPs) in IRF6 and NSCL/P in an Iranian population.Methods:A group of 105 children with NSCL/P and 185 normal controls were included in the current study. Genotyping of IRF6 rs2013162 and rs2235375 was performed by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method.Results:A substantial association of AA and CA genotypes in rs2013162 with the risk of NSCL/P (AA vs. CC; OR=2.36; 95%CI [1.05–5.29], p=0.004; and CA vs. CC; OR=0.47; 95%CI [0.28–0.79], p=0.018) was found. However, there were no important associations between A allele and risk of NSCL/P (p=0.980). According to logistic regression analysis results, subjects with GG genotype and G allele in rs2235375 polymorphism had increased risk of NSCL/P.Conclusion:The IRF6 polymorphisms are associated with the susceptibility to NSCL/P in Iranian population.