Nonsyndromic Orofacial Clefts Research Articles

Whole-exome sequencing identifies ECPAS as a novel potentially pathogenic gene in multiple hereditary families with nonsyndromic orofacial cleft.

Whole-exome sequencing identifies ECPAS as a novel potentially pathogenic gene in multiple hereditary families with nonsyndromic orofacial cleft.

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.

Potential of Viruses as Environmental Etiological Factors for Non-Syndromic Orofacial Clefts.

In this study, we analyzed the potential of viral infections in the species Homo sapiens as environmental causes of orofacial clefts (OFCs). A scoring system was adapted for qualitatively assessing the potential of viruses to cause cleft lip and/or palate (CL/P). This assessment considered factors such as information from the literature, nucleotide and amino acid similarities, and the presence of Endogenous Viral Elements (EVEs). The analysis involved various algorithm packages within Basic Local Alignment Search Tool 2.13.0 software and databases from the National Center for Biotechnology Information and the International Committee on Taxonomy of Viruses. Twenty significant viral species using different biosynthesis strategies were identified: Human coronavirus NL63, Rio Negro virus, Alphatorquevirus homin9, Brisavirus, Cosavirus B, Torque teno mini virus 4, Bocaparvovirus primate2, Human coronavirus HKU1, Monkeypox virus, Mammarenavirus machupoense, Volepox virus, Souris mammarenavirus, Gammapapillomavirus 7, Betainfluenzavirus influenzae, Lymphocytic choriomeningitis mammarenavirus, Ledantevirus kern, Gammainfluenzavirus influenzae, Betapolyomavirus hominis, Vesiculovirus perinet, and Cytomegalovirus humanbeta5. The evident viral etiological potential in relation to CL/P varies depending on the Baltimore class to which the viral species belongs. Given the multifactorial nature of CL/P, this relationship appears to be dynamic.

Congenital cardiac anomalies in non-syndromic cleft lip and cleft palate patients: A systematic review and meta-analysis.

The aim was to establish a specific and definite connection between non-syndromic orofacial cleft patients and associated congenital heart disease (CHD). Following PRISMA guidelines, selective databases were searched for data collection. Studies showing a definite association of CHD with orofacial cleft were included, and studies non-specific of the association of orofacial cleft with CHD were excluded. Data extraction criteria were study design, frequency of CHD in overall non-syndromic orofacial cleft and in specific cleft type, and most prevalent congenital cardiac anomaly. DerSimonian Laird random effects model was used to estimate the pooled proportion of CHD, along with corresponding 95% confidence intervals (CIs) for each measure. Publication bias was assessed using Fail-Safe N analysis and the Rosenthel approach. Of a total of 182 articles searched, only 30 studies were assessed. The overall pooled estimate of the proportion of CHD in total cleft lips/palates was 16% (95% CI: 13-19). The odds of developing CHD in cleft palates was 4.08 times more as compared to cleft lips with 95% CIs of 3.86-4.33, and 1.65 more as compared to cleft lips and palates both with 95% CI of 1.52-1.68. We affirm the upsurging prevalence of CHD in non-syndromic cleft children and vehemently propose that it is of utmost importance to inculcate it in practice and policy-making to screen all non-syndromic orofacial cleft children for congenital cardiac anomaly. This study was registered on PROSPERO (ID no. CRD42023391597) on February 24, 2023.

A common cis-regulatory variant impacts normal-range and disease-associated human facial shape through regulation of PKDCC during chondrogenesis.

Genome-wide association studies (GWAS) identified thousands of genetic variants linked to phenotypic traits and disease risk. However, mechanistic understanding of how GWAS variants influence complex morphological traits and can, in certain cases, simultaneously confer normal-range phenotypic variation and disease predisposition, is still largely lacking. Here, we focus on rs6740960, a single nucleotide polymorphism (SNP) at the 2p21 locus, which in GWAS studies has been associated both with normal-range variation in jaw shape and with an increased risk of non-syndromic orofacial clefting. Using in vitro derived embryonic cell types relevant for human facial morphogenesis, we show that this SNP resides in an enhancer that regulates chondrocytic expression of PKDCC - a gene encoding a tyrosine kinase involved in chondrogenesis and skeletal development. In agreement, we demonstrate that the rs6740960 SNP is sufficient to confer chondrocyte-specific differences in PKDCC expression. By deploying dense landmark morphometric analysis of skull elements in mice, we show that changes in Pkdcc dosage are associated with quantitative changes in the maxilla, mandible, and palatine bone shape that are concordant with the facial phenotypes and disease predisposition seen in humans. We further demonstrate that the frequency of the rs6740960 variant strongly deviated among different human populations, and that the activity of its cognate enhancer diverged in hominids. Our study provides a mechanistic explanation of how a common SNP can mediate normal-range and disease-associated morphological variation, with implications for the evolution of human facial features.

Prevalence of Dental Anomalies in Patients with Non-syndromic Cleft Lip with or without Cleft Palate

This study aimed to assess the prevalence and distribution pattern of dental anomalies in the permanent teeth of patients with non-syndromic cleft lip with or without cleft palate. Additionally, it aimed to compare differences in dental anomalies between cleft and non-cleft areas, considering gender and cleft phenotype. Panoramic radiographs of 164 patients diagnosed with non-syndromic orofacial clefts were retrospectively analyzed by a single examiner to confirm dental anomalies. The dental anomalies investigated included tooth agenesis, supernumerary teeth, microdontia, rotation, ectopic eruption, and enamel hypoplasia. Cleft phenotypes were categorized into 7 types based on medical and dental records. A significantly higher prevalence of supernumerary teeth was observed in males than females within non-cleft areas (<i>p</i> = 0.017), with no significant differences in other dental anomalies. In non-cleft area, patients with cleft palate exhibited a high prevalence of tooth agenesis (<i>p</i> < 0.0001) and microdontia (<i>p</i> = 0.012) compared to other cleft phenotypes. Maxillary incisor rotation was closely associated with adjacent tooth agenesis in unilateral cleft lip and palate cases (<i>p</i> = 0.034). This study suggests that the additional subphenotype based on dental anomalies in patients with orofacial cleft may serve as applicable clinical markers.

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

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. 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. 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. 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.

Maternal Exposure to Stress During Covid-19 and Non-Syndromic Orofacial Clefts: A Cohort Retrospective Study.

The coronavirus (COVID-19) pandemic presents an opportunity to study stress's effect on the development of non-syndromic orofacial clefts (NSOFCs). This study was aimed at assessing maternal stress exposure during the pregestational to first trimester pregnancy periods and the development of NSOFCs during a year of the COVID-19 pandemic. Cohort study of infants with NSOFCs and controls matched based on recruitment site and age. Government hospitals in Saudi Arabia between November 2020 and November 2021. Data collection included NSOFC clinical examination and maternal stress exposure assessment using the Modified Life Events Questionnaire, the Fear of COVID-19 Scale, and a focus on the lack of pregnancy planning and a threatened miscarriage. Of the 557 infants recruited, 191 had NSOFCs. Logistic regression analysis with adjusted odds ratios (AORs) that removed the effects of confounders showed that any of the seven stressful life events (AOR:3.78, P < .001) and the family histories of relatives with NSOFCs (AOR:9.73, P < .001) increased the AOR for NSOFC development. In contrast, maternal folic acid (AOR:0.56, P.010), threatened miscarriage (AOR:0.17, P = .001), fear of COVID-19 (AOR:0.83, P = .038), and suspected COVID-19 infection (AOR:0.43, P = .008) decreased the AOR for NSOFC development. Along with an established risk associated with family history of birth defects, stressful life events may be a risk factor for NSOFC development. Beyond folic acid's known benefit, it may be that higher maternal health concerns contribute to increased protective health behaviors during pregnancy. Ongoing research is needed to specify the maternal risk factors for NSOFC.

Assessment of non-syndromic orofacial cleft severity and associated environmental factors in Saudi Arabia: A cross-sectional study

ObjectiveTo evaluate the relationship between different environmental risk factors and the severity of cleft lip with/without palate (CL ± P) and cleft palate (CP) in Saudi Arabia. MethodsThis was a cross-sectional national study, of government hospitals in 10 cities distributed across major regions of Saudi Arabia, from June 2020 to June 2021. All newborns with CL ± P or CP were clinically examined and evaluated for cleft phenotype severity using the LAHSHAL classification system. Various environmental factors were evaluated by interviewing parents using a validated questionnaire. The severity of CL ± P and CP was evaluated in relation to environmental factors. ResultsWe recruited 174 patients with non-syndromic orofacial cleft (NSOFC); 122 (70.1 %) had CL ± P and 52 (29.9 %) had CP. After adjusting the odds ratios by ordinal regression for CL ± P and logistic regression analysis for CP, environmental factors that significantly increased the severity of CL ± P were family history of NSOFC, maternal illnesses, and maternal medication use (P = 0.02, adjusted odds ratio [AOR]:2.70; P = 0.002, AOR:3.70; and P = 0.03, AOR:2.14, respectively). Folic acid supplementation in the first trimester significantly reduced the severity of CL ± P and CP (P = 0.001, AOR:0.18 and P = 0.001, AOR:0.012, respectively). ConclusionThe severity of CL ± P was affected by some maternal exposures during the 3-month pre-gestation period. Therefore, our results suggest the possibility of controlling the severity of NSOFC.

Incidence of non-syndromic orofacial cleft during the COVID-19 pandemic in Saudi Arabia

ObjectivesThis is the first national study to investigate the incidence of non-syndromic oro-facial clefts (NSOFC) and Pierre-Robin-Sequence in Saudi Arabia over the Covid-19 pandemic period.MethodsAll maternity hospitals (30-hospitals) in the major regions and cities of Saudi from November 2020-to-2021 were included in the study. Patients were evaluated for cleft phenotype using the LASHAL-classification system. The incidence of NSOFC in Saudi Arabia was calculated by comparing the number of NSOFCs cases born out of all live births during the study period at the included hospitals. Clinical examination was performed and information was gathered using a validated data collection form.ResultsIn one year, 140,380 live-infants were born at the selected hospitals. Of these, 177 were diagnosed with NSOFC giving an incidence of 1.26/1,000 live-births in Saudi Arabia and the highest incidence in Medina city (2.46/1000 live-births). The incidence of cleft lip-and-palate (0.67/1000 live-births) was higher than that of cleft-palate (0.37/1000 live-births) and cleft-lip (0.22/1000 live-births). Pierre-Robin Sequence incidence was (0.04/1000 live-births). There were 21(12.1) or 23(13.2%) of NSOFC’s mothers exposed or vaccinated with Covid-19, respectively.ConclusionThe national incidence of NSOFC in Saudi Arabia was 1.26/1000 live births with variation between phenotypes and regions in the country. In addition, to reporting Covid-19 infection prevalence and vaccine exposure among NSOFC's mothers, this study represents the first of its type to evaluate NSOFC prevalence in Saudi Arabia on a national level.

Whole Exome Sequencing Identifies Damaging Variants in Indonesians with Clefts.

The interaction between genomics, genetic and environmental factors have been implicated in non-syndromic orofacial cleft development. In the current study, we investigated the contributions of rare and novel genetic variants in known cleft genes using whole exome sequencing (WES) data of Indonesians with non-syndromic orofacial clefts. WES was conducted on 6 individuals. Variants in their exons were called and annotated. These variants were filtered for novelty and rarity using MAF of 0 and 1%. Hospital in Indonesia. Indonesians with non-syndromic orofacial clefts. Deleterious variants were prioritized. Pathogenic amino acid changes effect on protein structure and function were identified using HOPE. Rare and novel variants in known cleft genes were filtered and their deleteriousness were predicted using polyphen, SIFT and CADD. We identified rare (MAF <1%) deleterious variants in 4 craniofacial genes namely MMACHC (rs371937044, MAF = 0.00011). SOS1 (rs190222208, MAF = 0.00045), TULP4 (rs199583035, MAF = 0.067), and MTHFD1L (rs143492706, MAF = 0.0044). MMACHC has a mouse knockout model with facial cleft and failure of palatal fusion. The individual with variant in MMACHC presented with nsCPO. Our study provides additional evidence for the role of TULP4, SOS1, MTHFD1L and MMACHC genes in nsOFC development. This is the first time MMACHC is implicated in nsOFC development in humans.

Association between IRF6, TP63, GREM1 Gene Polymorphisms and Non-Syndromic Orofacial Cleft Phenotypes in Vietnamese Population: A Case-Control and Family-Based Study.

This study aims to identify potential variants in the TP63-IRF6 pathway and GREM1 for the etiology of non-syndromic orofacial cleft (NSOFC) among the Vietnamese population. By collecting 527 case-parent trios and 527 control samples, we conducted a stratified analysis based on different NSOFC phenotypes, using allelic, dominant, recessive and over-dominant models for case-control analyses, and family-based association tests for case-parent trios. Haplotype and linkage disequilibrium analyses were also conducted. IRF6 rs2235375 showed a significant association with an increased risk for non-syndromic cleft lip and palate (NSCLP) and cleft lip with or without cleft palate (NSCL/P) in the G allele, with pallele values of 0.0018 and 0.0003, respectively. Due to the recessive model (p = 0.0011) for the NSCL/P group, the reduced frequency of the GG genotype of rs2235375 was associated with a protective effect against NSCL/P. Additionally, offspring who inherited the G allele at rs2235375 had a 1.34-fold increased risk of NSCL/P compared to the C allele holders. IRF6 rs846810 and a G-G haplotype at rs2235375-rs846810 of IRF6 impacted NSCL/P, with p-values of 0.0015 and 0.0003, respectively. In conclusion, our study provided additional evidence for the association of IRF6 rs2235375 with NSCLP and NSCL/P. We also identified IRF6 rs846810 as a novel marker associated with NSCL/P, and haplotypes G-G and C-A at rs2235375-rs846810 of IRF6 associated with NSOFC.

Orofacial Clefts: Genetics of Cleft Lip and Palate.

Orofacial clefting is considered one of the commonest birth defects worldwide. It presents as cleft lip only, isolated cleft palate or cleft lip and palate. The condition has a diverse genetic background influenced by gene-gene and gene-environment interaction, resulting in two main types, syndromic and nonsyndromic orofacial clefts. Orofacial clefts lead to significant physiological difficulties that affect feeding, speech and language development and other developmental aspects, which results in an increased social and financial burden on the affected individuals and their families. The management of cleft lip and palate is solely based on following a multidisciplinary team approach. In this narrative review article, we briefly summarize the different genetic causes of orofacial clefts and discuss some of the common syndromes and the approach to the management of orofacial clefts.

Clinically actionable secondary findings in 130 triads from sub-Saharan African families with non-syndromic orofacial clefts.

The frequency and implications of secondary findings (SFs) from genomic testing data have been extensively researched. However, little is known about the frequency or reporting of SFs in Africans, who are underrepresented in large-scale population genomic studies. The availability of data from the first whole-genome sequencing for orofacial clefts in an African population motivated this investigation. In total, 130 case-parent trios were analyzed for SFs within the ACMG SFv.3.0 list genes. Additionally, we filtered for four more genes (HBB, HSD32B, G6PD and ACADM). We identified 246 unique variants in 55 genes; five variants in four genes were classified as pathogenic or likely pathogenic (P/LP). The P/LP variants were seen in 2.3% (9/390) of the subjects, a frequency higher than ~1% reported for diverse ethnicities. On the ACMG list, pathogenic variants were observed in PRKAG (p. Glu183Lys). Variants in the PALB2 (p. Glu159Ter), RYR1 (p. Arg2163Leu) and LDLR (p. Asn564Ser) genes were predicted to be LP. This study provides information on the frequency and pathogenicity of SFs in an African cohort. Early risk detection will help reduce disease burden and contribute to efforts to increase knowledge of the distribution and impact of actionable genomic variants in diverse populations.

Otological Challenges in Patients With Non-Syndromic Cleft Lip and Palate: A Systematic Review

Objectives: To identify the various otological challenges associated with non-syndromic orofacial clefts, how these problems affect quality of life of patients with orofacial clefts and find out the perspectives and current trends in the management of otological problems. Design: We conducted systematic searches for retrospective studies, cross-sectional studies, case-control studies, cohorts’ longitudinal studies and prospective controlled trials in Medline and Google scholar databases. Identified studies were retrieved and assessed for eligibility. Results: Thirty-five articles met all inclusion criteria and were selected for qualitative analysis. Twenty-one articles evaluated otological challenges associated with cleft lip and palate, 7 articles evaluated associated quality of life of patients with otological challenges and 9 articles evaluated management of otological challenges. Based on the results from this review, otological challenges including otitis media with effusion, conductive and sensorineural hearing loss are commonly associated with cleft. The result is a reduced quality of life due to their negative effects on intelligibility and eloquence of speech. They can however be managed by various palatoplasty procedures, rapid maxillary expansion, and use of various otological aids performed at an early age. Conclusion: The prevalence otological challenges in the cleft population are high and these issues require early management due to their possible effects on quality of life. Hence, there is need to incorporate ear care in the routine management of cleft lip and palate.

Genome-wide meta-analyses identify five new risk loci for nonsyndromic orofacial clefts in the Chinese Han population.

Nonsyndromic orofacial clefts (NSOFCs) are the most common craniofacial birth malformations in humans and are generally classified as nonsyndromic cleft lip with or without cleft palate (NSCL/P) and nonsyndromic cleft palate only (NSCPO). Genome-wide association studies (GWASs) of NSOFCs have demonstrated multiple risk loci and candidate genes; however, published risk factors are able to explain only a small fraction of the observed NSOFCs heritability. Here, we performed GWASs of 1615 NSCPO cases and 2340 controls, and then conducted genome-wide meta-analyses of NSOFCs, totaling 6812 NSCL/P cases, 2614 NSCPO cases, and 19,165 controls from the Chinese Han population. We identify 47 risk loci with genome-wide pmeta -value <5.0 × 10-8 , 5 risk loci (1p32.1, 3p14.1, 3p14.3, 3p21.31, and 13q22.1) of which are new. All of the 47 susceptibility loci conjointly account for 44.12% of the NSOFCs' heritability in the Chinese Han population. Our results improve the comprehending of genetic susceptibility to NSOFCs and provide new views into the genetic etiology of craniofacial anomalies.

Integrating transcriptomics and genomics to identify fibroblast growth factor/receptor candidate genes for non‐syndromic orofacial cleft in Chinese

ObjectivesThe objective of this study was to explore the relationship between fibroblast growth factor/receptor (FGF/FGFR) and non-syndromic orofacial cleft (NSOC) in individuals of Han Chinese. DesignInitially, we performed RNA-Seq between non-syndromic cleft lip only (NSCLO) or non-syndromic cleft palate only (NSCPO) and control groups. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were carried out to evaluate the functions of differentially expressed genes (DEGs) of FGF/FGFR. Then, we selected the most significant DEG FGFR2 and performed an association analysis in Chinese. Linkage disequilibrium (LD) and haplotype analyses were performed with HaploView and PLINK. Additional bioinformatics functional prediction for the notable single nucleotide polymorphisms was performed with HaploReg V4.1 and 3DSNP. ResultsFinally, we identified 32 mRNAs related to FGF/FGFR via RNA-Seq and chose FGFR2 in the subsequent association analysis. Results indicated that the single nucleotide polymorphism (SNP) rs2288336 in FGFR2 contributed significantly to both non-syndromic cleft lip with or without cleft palate (NSCL/P) and NSCLO, with p values of 5.00E-05 (OR = 0.79, 95% CI: 0.70–0.88) and 1.38E-04 (OR = 0.76, 95% CI: 0.65–0.87), respectively. In addition, rs3793893 in FGFR2 was found to be associated with NSCLO, with a p value of 1.02E-04 (OR = 0.67, 95% CI: 0.55–0.82). ConclusionsOur research demonstrated that FGFR2 is significantly more involved in NSOC than other FGF/FGFRs in Chinese and further identified rs2288336 and rs3793893 in FGFR2 associated with NSOC subtypes, which provide further evidence for the genetic etiology of NSOC in Han Chinese.

Environmental tobacco smoke exposure and non-syndromic orofacial cleft: Systematic review and meta-analysis.

Environmental tobacco smoke (ETS) is associated with several congenital anomalies, including non-syndromic orofacial clefts (NSOFCs). This systematic review aimed to update the literature on the association between ETS and NSOFCs. Four databases were searched up to March 2022, and studies that evaluated the association between ETS and NSOFCs were selected. Two authors selected the studies, extracted the data, and evaluated the risk of bias. Comparing the association of maternal exposure to ETS and active parental smoking with NSOFCs allowed for the creation of pooled effect estimates for the included studies. Twenty-six studies were deemed eligible for this review, of which 14 were reported in a previous systematic review. Twenty five were case-control studies, and one was a cohort study. In total, these studies included 2142 NSOFC cases compared to 118129 controls. All meta-analyses showed an association between ETS and the risk of having a child with NSOFC, based on the cleft phenotype, risk of bias, and year of publication, with a pooled increased odds ratio of 1.80 (95% CI: 1.51-2.15). These studies had a marked heterogeneity, which decreased upon subgrouping based on the recent year of publication and the risk of bias. ETS exposure was associated with more than a 1.5-fold increase in the risk of having a child with NSOFC, showing a higher odds ratio than paternal and maternal active smoking. The study is registered on the International Prospective Register of Systematic Reviews database # CRD42021272909.

Ethnic Differences in the Brazilian Population Influence the Impact of BMP4 Genetic Variants on Susceptibility of Nonsyndromic Orofacial Clefts.

The study evaluated the association of BMP4 tag-SNPs and SNP-SNP interactions involving genes active by BMP4 pathway during craniofacial development in the susceptibility of nonsyndromic orofacial clefts (NSOC) in the Brazilian population. Case-control study. Brazilian Oral Cleft Group. The study included 881 healthy controls and 800 patients with different types of NSOC: 232 with cleft lip only (NSCLO), 568 with cleft lip and palate (NSCLP), and 274 with cleft palate only (NSCPO). The genomic DNA was genotyped with allelic discrimination assays for five BMP4 tag-SNPs (rs11623717, rs17563, rs2071047, rs2761887 and rs4898820), and analyzed their allelic and genotypic associations using multiple logistic regression. The interactions of these variants with genes involved in the BMP4 signaling pathway, including FGFR1, GREM1, NOG, VAX1 and the 4p16.2 locus, were explored. BMP4 variants in the NSOC risk. Although only nominal p values were identified when the whole sample was considered, subgroup analysis including the patients with high African genomic ancestry showed significant associations of rs2761887 with risk for nonsyndromic cleft lip with or without cleft palate (NSCL ± P)[(ORhom: 2.16; 95% CI: 1.21-3.85; p = 0.01) and (ORrec: 2.05; 95% CI: 1.21-3.47; p = 0.006)]. Thirteen significant SNP-SNP interactions involving BMP4 and the SNPs at FGFR1, GREM1, NOG and VAX1 and at locus 4p16.2 for increased risk of NSCL ± P were identified. Our results demonstrate an increased risk of NSCL ± P in Brazilian individuals with enrichment of African ancestry in the presence of the BMP4 rs2762887 polymorphism, and reveal relevant genetic contribution of SNP-SNP epistatic interactions involving BMP4 variants to NSCL ± P risk.

COVID-19 related risk factors and their association with non-syndromic orofacial clefts in five Arab countries: a case-control study

BackgroundThe environmental etiology of non-syndromic orofacial clefts (NSOFCs) is still under research. The aim of this case-control study is to assess COVID-19 associated factors that may be related to the risk of NSOFC in five Arab countries. These factors include COVID-19 infection, COVID-19 symptoms, family member or friends infected with COVID-19, stress, smoking, socioeconomic status and fear of COVID-19.MethodsThe study took place in governmental hospitals in five Arab countries from November 2020 to November 2021. Controls are matched in the month of delivery and site of recruitment. A clinical examination was carried out using LASHAL classification. Maternal exposure to medication, illnesses, supplementation, COVID-19 infection during their pregestation and 1st trimester periods were evaluated using a validated questionnaire. Maternal exposure to stress was assessed using the Life Events scale, fear of covid-19 scale, family member or friend affected with covid-19 infection, pregnancy planning and threatened abortion.ResultsThe study recruited 1135 infants (386 NSOFC and 749 controls). Living in urban areas, maternal exposure to medications 3-months pregestation, maternal exposure to any of the prenatal life events and maternal fear of COVID-19 significantly increased the risk of having a child with NSOFC. On the other hand, mothers exposed to supplementation 3-months pregestation, mothers suspected of having COVID-19 infection, family members or friends testing positive with COVID-19 significantly decreased the risk of having a child with NSOFC.ConclusionsThis study suggests that NSOFC may be associated with maternal exposure to lifetime stress and COVID-19 fear in particular, with no direct effect of the COVID-19 infection itself. This highlights the importance of providing psychological support for expecting mothers during stressful events that affect populations such as the COVID-19 pandemic, in addition to the usual antenatal care.