Single-cell transcriptome and chromatin accessibility mapping of upper lip and primary palate fusion.

Cleft lip and/or primary palate (CL/P) represent a prevalent congenital malformation, the aetiology of which is highly intricate. Although it is generally accepted that the condition arises from failed fusion between the upper lip and primary palate, the precise mechanism underlying this fusion process remains enigmatic. In this study, we utilized transposase-accessible chromatin sequencing (scATAC-seq) and single-cell RNA sequencing (scRNA-seq) to interrogate lambdoidal junction tissue derived from C57BL/6J mouse embryos at critical stages of embryogenesis (10.5, 11.5 and 12.5 embryonic days). We successfully identified distinct subgroups of mesenchymal and ectodermal cells involved in the fusion process and characterized their unique transcriptional profiles. Furthermore, we conducted cell differentiation trajectory analysis, revealing a dynamic repertoire of genes that are sequentially activated or repressed during pseudotime, facilitating the transition of relevant cell types. Additionally, we employed scATAC data to identify key genes associated with the fusion process and demonstrated differential chromatin accessibility across major cell types. Finally, we constructed a dynamic intercellular communication network and predicted upstream transcriptional regulators of critical genes involved in important signalling pathways. Our findings provide a valuable resource for future studies on upper lip and primary palate development, as well as congenital defects.

Congenital diaphragmatic hernia and cleft lip and palate: looking for a common genetic etiology.

PURPOSE: Congenital diaphragmatic hernia (CDH) and cleft lip and/or palate (CL/P) are inborn closure defects. Genetic factors in and outcomes for patients with both anomalies (CDH+CL/P) remain unclear. We aimed to investigate associated genetic aberrations, prevalence of, and outcomes for, CDH+CL/P. METHODS: Data from Congenital Diaphragmatic Hernia Study Group (CDHSG) registry were collected. CL/P prevalence in CDH patients was determined. Genetic abnormalities and additional malformations in CDH+CL/P were explored. Patient characteristics and outcomes were compared between CDH+CL/P and isolated CDH (CDH-) using Fisher's Exact Test for categorical, and t-test or Mann-Whitney U-test for continuous, data. p < 0.05 was considered statistically significant. RESULTS: Genetic anomalies in CDH+CL/P included trisomy 13, 8p23.1 deletion, and Wolf-Hirschhorn syndrome (4p16.3 deletion). CL/P prevalence in CDH was 0.7%. CDH+CL/P had lower survival rates than CDH-, a nearly fourfold risk of death within 7 days, were less supported with extracorporeal life support (ECLS), had higher non-repair rates, and survivors had longer length of hospital stay. CONCLUSION: Genetic anomalies, e.g. trisomy 13, 8p23.1 deletion, and Wolf-Hirschhorn syndrome, are seen in patients with the combination of CDH and orofacial clefts. CL/P in CDH patients is rare and associated with poorer outcomes compared to CDH-, influenced by goals of care decision-making.

Proteomic analysis illustrates the potential involvement of motor proteins in cleft palate development.

Cleft palate (CP) is a congenital condition characterized by a complex etiology and limited diagnostic and therapeutic options. In this study, we delved into the molecular mechanisms associated with retinoic acid (RA)-induced CP in Kun Ming mice. Proteomic analysis of control and RA-induced CP samples at embryonic day 15.5 revealed 25 upregulated and 19 downregulated proteins. Further analysis identified these differentially expressed proteins (DEPs) as being involved in extracellular matrix organization, actin cytoskeleton, and myosin complex. Moreover, these DEPs were found to be enriched in pathways related to motor protein activity and extracellular matrix-receptor interaction. Protein-protein interaction network analysis identified 10 hub proteins, including motor proteins and ECM-related proteins, which exhibited higher expression levels in CP compared to control tissues. These findings provide insights into the molecular mechanisms underlying CP and highlight potential targets for diagnostic and therapeutic purposes.

Alterations of senescence-associated markers in patients with non-syndromic cleft lip and palate.

Non-syndromic cleft lip with or without cleft palate (NSCL/P) is one of the most common craniofacial anomalies. Abnormal Alu methylation in DNA of the pregnant mother may influence the abnormal development of the child. This study aimed to examine Alu methylation and cellular senescence in NSCL/P patients and their mothers as well as the correlation with the severity of NSCL/P. A total of 39 patients with NSCL/P and 33 mothers were enrolled. Of these patients, 6 were cleft lip only (CLO), 9 were cleft palate only (CPO), and 24 were cleft lip and palate (CLP). Alu methylation and senescence markers were determined in the white blood cells of NSCL/P patients, their mothers, and in the lip and palatal tissues of patients at the time of cheiloplasty and palatoplasty. Total Alu methylation was not significantly different between groups. However, a decrease in Alu hypermethylation, increased partial Alu methylation, RAGE, and p16 expression were shown in CLP, the most severe cleft type. Alu methylation in tissues did not differ between groups. In mothers, an increase in Alu methylation was observed only in the CLP. Therefore, the pathogenesis of NSCL/P may be related to Alu methylation of the mother promoting loss of Alu methylation and subsequently senescence in the children.

Investigating Single Nucleotide Polymorphisms in the Etiology of Cleft Lip and Cleft Palate in the Polish Population.

Cleft lip and/or palate (CL/P) are the most common congenital anomalies in the craniofacial region, leading to morphological and functional disruptions in the facial region. Their etiology involves genetic and environmental factors, with genetics playing a crucial role. This study aimed to investigate the association of four single nucleotide polymorphisms (SNPs)-rs987525, rs590223, rs522616, and rs4714384-with CL/P in the Polish population. We analyzed DNA samples from 209 individuals with CL/P and 418 healthy controls. The impact of SNPs on the presence of CL/P was assessed using multivariate logistic regression. Significant associations were found with rs987525. Specifically, the AC genotype was linked to an increased CL/P risk (odds ratio [OR] = 1.95, 95% confidence interval [CI]: 1.34-2.83, p < 0.001), while the CC genotype was associated with a decreased risk (OR = 0.46, 95% CI: 0.32-0.67, p < 0.001). Rs4714384 was also significant, with the CT genotype correlated with a reduced risk of CL/P (OR = 0.66, 95% CI: 0.46-0.94, p = 0.011). SNPs rs590223 and rs522616 did not show statistically significant associations. These results underscore the role of rs987525 and rs4714384 in influencing CL/P risk and suggest the utility of genetic screening in understanding CL/P etiology.

Functional analysis of ESRP1/2 gene variants and CTNND1 isoforms in orofacial cleft pathogenesis.

Orofacial cleft (OFC) is a common human congenital anomaly. Epithelial-specific RNA splicing regulators ESRP1 and ESRP2 regulate craniofacial morphogenesis and their disruption result in OFC in zebrafish, mouse and humans. Using esrp1/2 mutant zebrafish and murine Py2T cell line models, we functionally tested the pathogenicity of human ESRP1/2 gene variants. We found that many variants predicted by in silico methods to be pathogenic were functionally benign. Esrp1 also regulates the alternative splicing of Ctnnd1 and these genes are co-expressed in the embryonic and oral epithelium. In fact, over-expression of ctnnd1 is sufficient to rescue morphogenesis of epithelial-derived structures in esrp1/2 zebrafish mutants. Additionally, we identified 13 CTNND1 variants from genome sequencing of OFC cohorts, confirming CTNND1 as a key gene in human OFC. This work highlights the importance of functional assessment of human gene variants and demonstrates the critical requirement of Esrp-Ctnnd1 acting in the embryonic epithelium to regulate palatogenesis.

Cleft Palate Induced by Augmented Fibroblast Growth Factor-9 Signaling in Cranial Neural Crest Cells in Mice.

Although enhanced fibroblast growth factor (FGF) signaling has been demonstrated to be crucial in many cases of syndromic cleft palate caused by tongue malposition in humans, animal models that recapitulate this phenotype are limited, and the precise mechanisms remain elusive. Mutations in FGF9 with the effect of either loss- or gain-of-function effects have been identified to be associated with cleft palate in humans. Here, we generated a mouse model with a transgenic Fgf9 allele specifically activated in cranial neural crest cells, aiming to elucidate the gain-of-function effects of Fgf9 in palatogenesis. We observed cleft palate with 100% penetrance in mutant mice. Further analysis demonstrated that no inherent defects in the morphogenic competence of palatal shelves could be found, but a passively lifted tongue prevented the elevation of palatal shelves, leading to the cleft palate. This tongue malposition was induced by posterior spatial confinement that was exerted by temporomandibular joint (TMJ) dysplasia characterized by a reduction in Sox9+ progenitors within the condyle and a structural decrease in the posterior dimension of the lower jaw. Our findings highlight the critical role of excessive FGF signaling in disrupting spatial coordination during palate development and suggest a potential association between palatal shelf elevation and early TMJ development.

Genetic associations and parent-of-origin effects of PVRL1 in non-syndromic cleft lip with or without cleft palate across multiple ethnic populations.

OBJECTIVES: This study investigated the associations of PVRL1 gene variants with non-syndromic cleft lip with or without cleft palate (NSCL/P) by evaluating transmission distortion and parent-of-origin (POO) effects in multiple ethnic populations. METHODS: We conducted allelic and genotypic transmission disequilibrium tests (TDT) on 10 single-nucleotide variants (SNVs) in PVRL1 using data from 142 Korean families with an affected child. POO effects were analyzed using the POO likelihood ratio test, comparing transmission rates of maternally and paternally inherited alleles. To assess generalizability and ethnic heterogeneity, we compared results from Korean families with data from the Center for Craniofacial and Dental Genetics, which included 2,226 individuals from 497 European and 245 Asian trios. RESULTS: TDT analysis identified significant over-transmission of the rs7940667 (G361V) C allele in Korean families (p=0.007), a finding replicated in both Asian (p=6.5×10-7) and European families (p=1.6×10-10). Eight SNVs showed strong TDT evidence in larger Asian and European datasets after multiple comparison corrections (p<0.0073). Of these, 4 SNVs (rs7940667, rs7103685, rs7129848, and rs4409845) showed particularly robust association (p<5×10-8). POO analysis revealed significant maternal over-transmission of the rs10790330-A allele in Korean families (p=0.044). This finding was replicated in European families (p=9.0×10-4). Additionally, 3 other SNVs, rs7129848 (p=0.001) and the linked SNVs rs3935406 and rs10892434 (p=0.025), exhibited maternal over-transmission in the validation datasets. CONCLUSIONS: Our findings provide robust evidence supporting the associations of PVRL1 variants with NSCL/P susceptibility. Further research is necessary to explore the potential clinical applications of these findings.

Association of prenatal Cleft Lip and Palate ultrasound abnormalities with copy number variants at a single Chinese tertiary center.

BACKGROUD: A systematic analysis was conducted to investigate the molecular etiology of fetal cleft lip and/or palate (CL/P) and the association between various types of CL/P and copy number variations (CNVs), as well as their impact on birth outcomes. METHODS: In this retrospective study conducted between January 2016 and July 2022, a cohort of pregnancies diagnosed with fetal CL/P was enrolled and comprehensive clinical data for all cases were extracted from our medical record database, including demographic data about the pregnancies, ultrasound findings, results of Chromosomal microarray (CMA), as well as relevant pregnant and perinatal outcomes. RESULTS: Among the 358 cases, 32 clinically significant variants in 29 (8.1%) fetuses with CL/P were detected by CMA. In 338 singleton pregnancies, the diagnostic yield of CMA in the context of CL/P fetuses was determined to be 7.7% (26/338). CP cases exhibited a relatively higher prevalence of pathogenic/likely pathogenic CNVs at a rate of 25% (3/12), followed by CLP cases at 8.0% (23/288). Notably, the CL group did not demonstrate any pathogenic/likely pathogenic CNV findings among the examined cases (0/38). The diagnostic rate of clinically significant variants was notably higher in the non-isolated CL/P group than in the isolated CL/P group (11/33, 33.3% vs. 15/305, 4.9%, p < 0.001). Within the remaining 20 twin pregnancies, three clinically significant variants (15%) were observed. CONCLUSIONS: This study provides powerful evidence supporting the efficacy of CMA as a valuable tool for facilitating the prenatal genetic diagnosis of fetal CL/P. The presence of CP and CLP in fetal cases demonstrated a relatively higher incidence of pathogenic/likely pathogenic CNVs. Moreover, when these cases were accompanied by additional ultrasound abnormalities, the likelihood of identifying diagnostic CNVs significantly increased. Conversely, cases of CL alone might not be associated with positive CNVs. The present data may significantly enhance prenatal diagnosis accuracy and facilitate informed genetic counseling for cases of fetal CL/P.

Identification of RESP18 Gene Mutations Linked to Hereditary Non-Syndromic Cleft Lip and Palate in a Southern Chinese Family.

BACKGROUND Non-syndromic cleft lip with cleft palate (NSCLP) is one of the most common congenital birth defects worldwide; it causes lifelong problems and imposes burdens on patients and their families. This study aimed to describe the genomic analysis and identification of de novo regulated endocrine-specific protein 18 (RESP18) rs2385404 and rs2385405 gene polymorphisms associated with NSCLP in a southern Chinese family and to improve prevention, treatment, and prognosis of NSCLP. MATERIAL AND METHODS We performed a genome-wide association study (GWAS) to investigate the association of NSCLP phenotype with gene mutation. We investigated a 5-persons NSCLP family to screen the genetic variation of Han nationality in southern Chinese. Whole-genome sequencing (WGS) was used to detect all candidate genetic variants, and whole-exome sequencing (WES) was implemented to further verify mutations. The Clinical Variation Data Base (ClinVar) was employed for screening gene mutations. Finally, Sanger sequencing was applied to verify gene variations. RESULTS The combined analysis of WGS, WES, and ClinVar showed that a total of 9 variation positions overlapped among the 3 study cohorts. Sanger sequencing verified Glu amino acid variation in 2 mutation sites (rs2385404, rs2385405) from the RESP18 gene, which caused abnormal RESP18 function and was associated with hereditary NSCLP. CONCLUSIONS The combined genomic results showed that 2 mutations (rs2385404 and rs2385405) of the RESP18 gene were related to NSCLP in the family. The RESP18 gene may play an important role in the etiology and pathogenesis of cleft lip and palate.

Access to genetic evaluation of 1463 individuals with orofacial cleft in Brazil.

OBJECTIVE: The current study delves into the accessibility of genetic evaluations for individuals with orofacial clefts (OC), comparing data between genetics and treatment centers across Brazil. METHODS: This cross-sectional retrospective study analyzed primary data from 1463 OC individuals registered in the Brazilian Database of Craniofacial Anomalies (BDCA) between 2008 and 2018 without age or sex selection. Diagnostic exam results stemming from research projects until 2023 were considered. RESULTS: Of the 1463 individuals with typical OC, 987 were non-syndromic, 462 were syndromic (SOC), 10 presented atypical forms, and three were not specified OC cases. The average age for accessing laboratory diagnosis was 8.5 years among SOC individuals. Notably, more SOC cases were registered in genetics centers than treatment and rehabilitation centers (37.1 % vs. 29 %, p = 0.0015). Those originating from genetics centers accessed diagnosis at an average age of 7.3 years, while those from treatment and rehabilitation centers experienced delays with an average age of 10.7 years (p = 0.0581). CONCLUSIONS: Irrespective of the center of origin, the data highlight delayed diagnosis and challenges in accessing genetic tests for the syndromic group. Given the widespread reliance on the public health system by most of the Brazilian population, disseminating this data can significantly contribute to shaping an informed perspective on healthcare access. These insights can improve public policies tailored to the unique needs of individuals with OC.

Correlation between FOXN3-SIN3A complex expression in peripheral blood and non-syndromic cleft lip and palate in Xinjiang.

OBJECTIVES: This work aimed to study the correlation between FOXN3-SIN3A complex expression and non-syndromic oral clefts (NSOC) in Xinjiang. METHODS: In this study, 60 patients with NSOC attending the People's Hospital of Xinjiang Uygur Autonomous Region were recruited into the case group, including 30 cleft lip with or without cleft palate (NSCL/P), 30 cleft palate only (CPO), and 30 healthy children in the control group. The expression levels of FOXN3, SIN3A, and NEAT1 in peripheral blood of each group were detected by high-throughput second-generation sequencing technology and quantitative reverse transcription polymerase chain reaction (RT-qPCR). Receiver operating characteristic (ROC) curve and area under the curve (AUC) were used to analyze the diagnostic efficiency of NSOC. RESULTS: The comparison of the NSOC and control groups showed that FOXN3, SIN3A, and NEAT1 genes increased compared with the control group. The differences were all statistically significant (P<0.05). The AUCs of FOXN3, SIN3A, and NEAT1 in the NSCL/P group were 0.933 [95%CI=(0.864, 1.000)], 0.822 [(95%CI=(0.713, 0.932)], and 1.000[95%CI= (1.000, 1.000)], respectively. The AUCs of FOX-N3, SIN3A, and NEAT1 in the CPO group were 0.891 [95%CI=(0.806, 0.976)], 0.688 [95%CI=(0.552, 0.824)], and 1.000 [95%CI=(1.000, 1.000)], respectively. CONCLUSIONS: The results showed a correlation between the rising gene expression of FOXN3, SIN3A, and NEAT1 in peripheral blood and the occurrence of NSOC in Xinjiang. This work provides a theoretical basis for further study of the FOXN3-SIN3A complex as biomarkers to facilitate the early screening, disease prediction, and early prevention of NSOC.

Rare variants analyses suggest novel cleft genes in the African population.

Non-syndromic orofacial clefts (NSOFCs) are common birth defects with a complex etiology. While over 60 common risk loci have been identified, they explain only a small proportion of the heritability for NSOFCs. Rare variants have been implicated in the missing heritability. Thus, our study aimed to identify genes enriched with nonsynonymous rare coding variants associated with NSOFCs. Our sample included 814 non-syndromic cleft lip with or without palate (NSCL/P), 205 non-syndromic cleft palate only (NSCPO), and 2150 unrelated control children from Nigeria, Ghana, and Ethiopia. We conducted a gene-based analysis separately for each phenotype using three rare-variants collapsing models: (1) protein-altering (PA), (2) missense variants only (MO); and (3) loss of function variants only (LOFO). Subsequently, we utilized relevant transcriptomics data to evaluate associated gene expression and examined their mutation constraint using the gnomeAD database. In total, 13 genes showed suggestive associations (p = E-04). Among them, eight genes (ABCB1, ALKBH8, CENPF, CSAD, EXPH5, PDZD8, SLC16A9, and TTC28) were consistently expressed in relevant mouse and human craniofacial tissues during the formation of the face, and three genes (ABCB1, TTC28, and PDZD8) showed statistically significant mutation constraint. These findings underscore the role of rare variants in identifying candidate genes for NSOFCs.

[Gene-gene/gene-environment interaction of transforming growth factor-ß signaling pathway and the risk of non-syndromic oral clefts].

OBJECTIVE: To explore the association between polymorphisms of transforming growth factor-ß (TGF-ß) signaling pathway and non-syndromic cleft lip with or without cleft palate (NSCL/P) among Asian populations, while considering gene-gene interaction and gene-environment interaction. METHODS: A total of 1 038 Asian NSCL/P case-parent trios were ascertained from an international consortium, which conducted a genome-wide association study using a case-parent trio design to investigate the genes affec-ting risk to NSCL/P. After stringent quality control measures, 343 single nucleotide polymorphism (SNP) spanning across 10 pivotal genes in the TGF-ß signaling pathway were selected from the original genome-wide association study(GWAS) dataset for further analysis. The transmission disequilibrium test (TDT) was used to test for SNP effects. The conditional Logistic regression models were used to test for gene-gene interaction and gene-environment interaction. Environmental factors collected for the study included smoking during pregnancy, passive smoking during pregnancy, alcohol intake during pregnancy, and vitamin use during pregnancy. Due to the low rates of exposure to smoking during pregnancy and alcohol consumption during pregnancy (<3%), only the interaction between maternal smoking during pregnancy and multivitamin supplementation during pregnancy was analyzed. The threshold for statistical significance was rigorously set at P =1.46×10-4, applying Bonferroni correction to account for multiple testing. RESULTS: A total of 23 SNPs in 4 genes yielded nominal association with NSCL/P (P<0.05), but none of these associations was statistically significant after Bonferroni' s multiple test correction. However, there were 6 pairs of SNPs rs4939874 (SMAD2) and rs1864615 (TGFBR2), rs2796813 (TGFB2) and rs2132298 (TGFBR2), rs4147358 (SMAD3) and rs1346907 (TGFBR2), rs4939874 (SMAD2) and rs1019855 (TGFBR2), rs4939874 (SMAD2) and rs12490466 (TGFBR2), rs2009112 (TGFB2) and rs4075748 (TGFBR2) showed statistically significant SNP-SNP interaction (P<1.46×10-4). In contrast, the analysis of gene-environment interactions did not yield any significant results after being corrected by multiple testing. CONCLUSION: The comprehensive evaluation of SNP associations and interactions within the TGF-ß signaling pathway did not yield any direct associations with NSCL/P risk in Asian populations. However, the significant gene-gene interactions identified suggest that the genetic architecture influencing NSCL/P risk may involve interactions between genes within the TGF-ß signaling pathway. These findings underscore the necessity for further investigations to unravel these results and further explore the underlying biological mechanisms.

Family-based GWAS for dental class I malocclusion and clefts.

BACKGROUND: Individuals born with cleft lip and/or palate who receive corrective surgery regularly have abnormal growth in the midface region such that they exhibit premaxillary hypoplasia. However, there are also genetic contributions to craniofacial morphology in the midface region, so although these individuals appear to have Class III skeletal discrepancy, their molar relationship may be Class I. Past genome-wide association studies (GWASs) on skeletal Class II and III malocclusion suggested that multiple genetic markers contribute to these phenotypes via a multifactorial inheritance model, but research has yet to examine the genetic markers associated with dental Class I malocclusion. Thus, our goal was to conduct a family based GWAS to identify genes across the genome that are associated with Class I malocclusion, as defined by molar relations, in humans with and without clefts. METHODS: Our cohort consisted of 739 individuals from 47 Filipino families originally recruited in 2006 to investigate the genetic basis of orofacial clefts. All individuals supplied blood samples for DNA extraction and genotyping, and a 5,766 single nucleotide polymorphism (SNP) custom panel was used for the analyses. We performed a transmission disequilibrium test for participants with and without clefts to identify genetic contributors potentially involved with Class I malocclusion. RESULTS: In the total cohort, 13 SNPs had associations that reached the genomic control threshold (p < 0.005), while five SNPs were associated with Class I in the cohort of participants without clefts, including four associations that were identified in the total cohort. The associations for the SNPs ABCA4 rs952499, SOX1-OT rs726455, and RORA rs877228 are of particular interest, as past research found associations between these genes and various craniofacial phenotypes, including cleft lip and/or palate. CONCLUSIONS: These findings support the multifactorial inheritance model for dental Class I malocclusion and suggest a common genetic basis for different aspects of craniofacial development.

Prevalence and clinical characterization of oral clefts in patients with chromosome trisomy 18.

OBJECTIVE: To verify the prevalence and perform the clinical characterization of oral clefts in a sample of patients with trisomy of chromosome 18 in Southern Brazil. METHODS: This was a retrospective cross-sectional study, performed in a reference clinical genetic service in Southern Brazil. The initial sample consisted of 77 patients diagnosed in the neonatal period with trisomy 18 treated at the Clinical Genetics Service of a referral hospital at Federal University of Health Sciences of Porto Alegre (UFCSPA). The patients' diagnosis was confirmed by karyotype and care was provided during their stay in the intensive care unit (ICU) of the hospital that is a reference in Southern Brazil for care for malformed patients. The period covered was from 1975 to 2020. RESULTS: During the study period, 77 patients diagnosed with trisomy 18 were treated, most of them in the ICU. Of these, 13 individuals were excluded due to incomplete data. The final sample consisted of 64 patients with an average age of 2.4 years of life, ranging from one day to 16 years old, the majority of whom were female. Regarding face dysmorphisms identified in the sample, three (4,68%) patients had cleft lip and two (3,11%) had cleft lip and palate. CONCLUSIONS: This study contributed to the recognition of the characteristics and prevalence of oral clefts in individuals with trisomy 18 in a sample of patients from Southern Brazil. In addition, we described the clinical alterations found in patients with oral clefts, as well as other associated comorbidities, such as cardiac, neurological and pulmonary comorbidities, as well as cranial and facial dysmorphisms.

Investigating gene functions and single-cell expression profiles of de novo variants in orofacial clefts.

Orofacial clefts (OFCs) are common congenital birth defects with various etiologies, including genetic variants. Online Mendelian Inheritance in Man (OMIM) annotated several hundred genes involving OFCs. Furthermore, several hundreds of de novo variants (DNVs) have been identified from individuals with OFCs. Some DNVs are related to known OFC genes or pathways, but there are still many DNVs whose relevance to OFC development is unknown. To explore novel gene functions and their cellular expression profiles, we focused on DNVs in genes that were not listed in OMIM. We collected 960 DNVs in 853 genes from published studies and curated these genes, based on the DNVs' deleteriousness, into 230 and 23 genes related to cleft lip with or without cleft palate (CL/P) and cleft palate only (CPO), respectively. For comparison, we curated 178 CL/P and 277 CPO genes from OMIM. In CL/P, the pathways enriched in DNV and OMIM genes were significantly overlapped (p = 0.002). Single-cell RNA sequencing (scRNA-seq) analysis of mouse lip development revealed that both gene sets had abundant expression in the ectoderm (DNV genes: adjusted p = 0.032, OMIM genes: adjusted p < 0.0002), while only DNV genes were enriched in the endothelium (adjusted p = 0.032). Although we did not achieve significant findings using CPO gene sets, which was mainly due to the limited number of DNV genes, scRNA-seq analysis implicated various expression patterns among DNV and OMIM genes. Our results suggest that combinatory pathway and scRNA-seq data analyses are helpful for contextualizing genes in OFC development.

A novel MED12 pathogenic variant in a female fetus with facial cleft and cardiac defects identified in the first trimester.

Trio exome sequencing was performed on a female fetus with an increased nuchal translucency, along with nasal bone hypoplasia, suspected cleft palate and abnormal outflow tract of the heart. A de novo heterozygous variant c.5500_5507del, p.(Tyr1834Argfs × 58) in the MED12 gene was detected. Loss-of-function variants in MED12 in females are associated with Hardikar syndrome (HS). A follow-up ultrasound at 15+5 weeks of gestation identified multiple fetal anomalies including bilateral cleft lip and palate, diaphragmatic hernia, atrioventricular septal defect, persistent truncus arteriosus, and bilateral renal pelvis dilation. Fetal autopsy confirmed the prenatal sonographic findings, and the MED12 variant was discussed by our multidisciplinary team to be the cause of fetal anomalies. Our case is the first prenatal one in which HS was diagnosed due to first trimester structural malformations. This case report presents another example of early identification of a major anomaly which allows earlier genetic diagnosis and more time for clinical management.