Van Der Woude Research Articles

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

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

Syndromic Orofacial Clefts - A Review of a Portuguese Central Hospital

Introduction: Orofacial clefts (OFCs) are a common congenital craniofacial malformation that derive from a complexity of genetic and environmental factors. Although OFCs are usually an isolated malformations, over 400 syndromes have been reported in association. Purpose: This study aims to characterize patients with syndromic OFCs that attend Cleft Lip/Palate multidisciplinary group clinic at Centro Hospitalar Universitario de Sao Joao in Porto-Portugal. Methods: A retrospective analysis of medical records from a cohort of patients that were observed between January 1992 and December 2018 was performed. The OFCs types were listed according to the Spina classification modified by Silva-Filho et al. OFCs laterality, family history, associated syndromes and identified gene anomalies were collected. Results: The group included 617 patients, of which 57.3% were males. From the total, 18.6% had cleft lip, 38.1% had cleft lip and palate and 42% isolated cleft palate, which was the most frequent. The least frequent was the group of atypical clefts (1.3%). One hundred and fifty-seven patients (25.4%) had a family history of clefting. Syndromes were identified in 149 of the patients: Pierre Robin sequence was the most common (n=48; 32.2%), followed by 22q11.2 deletion syndrome, Van der Woude, Goldenhar and oral-facial-digital syndrome. Pierre Robin sequence occurred with additional syndromes in 18 cases (12.1%). Discussion: This cohort has a 24.1% of an identifiable syndrome, number higher than described in the literature. The importance of monitoring the OFCs and associated syndromes is a key element not only to tailor the approach and management of the OFCs, the possible complications and to provide accurate and insightful genetic counseling.

Van der woude syndrome: A rare case report with brief review of literature

Anne Van der Woude, in 1954, described a rare autosomal dominant developmental disorder with lower lip pits and cleft lip and palate called Van der Woude syndrome. It is one of the most common syndromic orofacial clefting and accounts for 2% of all cleft cases. We report a case of Van der Woude syndrome in a 6-year old girl with characteristic features of congenital lower lip pits, surgically repaired cleft lip and palate and hypodontia.

Screening of IRF6 Variants in Patients Subjected to Genetic Association Studies for Nonsyndromic Cleft Lip/Palate

To screen for interferon regulatory factor 6 (IRF6) pathogenic variants in patients clinically diagnosed with nonsyndromic cleft lip palate (NSCL/P) and establish the proportion of misdiagnosed Van der Woude syndrome (VWS) cases, which could have biased previous NSCL/P case-control association studies. Retrospective case series. Tertiary care children's hospital. One hundred seventy-two unrelated Mexican patients with NSCL/P, 128 of whom had previously been included in a NSCL/P case-control association study. Sanger sequencing of the 9 IRF6 exons were performed, all variants respect with sequence reference were reported and classified for their pathogenic significance according to the American College of Medical Genetics and Genomics guidelines. Seven percent of cases were familial. No pathogenic variant was identified in IRF6. We identified 12 previously reported benign variants; their frequencies did not significantly differ from those reported for individuals of Mexican ancestry. Three of them were uncommon intronic variants not reported in ClinVar. The rs2235371 and rs2235375 variants, which were previously analyzed in a NSCL/P case-control association study (containing 132 patients, 128 of whom were analyzed herein) did not show discordant association results comparing to the 370 controls from the previous study. The misdiagnosis of IRF6-related VWS as NSCL/P appears to be infrequent in our sample, suggesting that mutational screening of IRF6 would have a low diagnostic yield in patients with NSCL/P. The absence of IRF6 pathogenic alleles could be related to the application of an exhaustive clinical evaluation that discarded the syndromic forms and/or the low proportion of familial cases included.

Clinical Findings and Outcomes of Palatal Repair in 9 Patients With Van der Woude Syndrome.

Van der Woude syndrome (VWS), an autosomal dominant condition associated with clefts of the lip and/or palate and lower lip pits, is caused by mutations in interferon regulatory factor 6 gene. It is reported to be the most common syndromic cleft worldwide. This case series presents the phenotypic characteristics and treatment outcomes in a group of 9 patients diagnosed with VWS. A retrospective review was performed on records of patients given a diagnosis of VWS presenting to the Department of Plastic Surgery of Sohag University between July 2009 and November 2019. Data analyses included age and sex of affected patients, type of the cleft, associated anomalies, presence of lower lip pits, and history of lower lip pits/cleft in the family and treatment outcomes. The study identified 9 patients (male = 2, female = 7). Age at first presentation ranged between 1 week and 7 years (mean = 1.3 years). Four patients had bilateral cleft lip and palate and 1 patient had unilateral cleft lip and palate (UCLP), whereas 4 patients had isolated cleft palate. Bilateral lower lip pits were presented in 8 patients, whereas the ninth patient has unilateral pit. Family history was positive in 3 patients. Most patients in this study developed after palatal repair speech problems with an increased rate of secondary surgical procedures needed for correction of velopharyngeal insufficiency. All reviewed cases of VWS presented with lower lip pits and cleft palate with or without cleft lip. A positive family history of similar conditions was demonstrated in 33.3% of our patients. This study suggests an increased incidence of secondary palatal surgeries for velopharyngeal insufficiency in patients with VWS; this warrant further studies including control group of nonsyndromic cleft patients.

Van der woude syndrome: A case report and review

Introduction: The prevalent autosomal disorder, with or without cleft palate and lip, is Van der Woude Syndrome (VWS). The condition has been known for its lower lip pits. Interferon Regulatory Factor 6 (IRF6) gene mutations are causing a range of cases of VWS. The furrows caused an accumulation of mucous and felt esthetic pain during meals and crying.Purpose: To determine VWS causes, prevalence, treatment, symptoms, and diagnosis.Case report: A six-month-old baby was with lip pits, a bilateral cleft lip and palate since birth. The extraoral exam showed bilateral pit swellings with dome form on the lower vermilion boundary laterally to the midline. Simultaneous operations with the Nordhoff technique and simple excision were conducted combined with a breakthrough procedure under general anesthesia to correct bilateral cleft lips. The patient showed better clinical condition after the seventh-day post-surgery without infection sign, and bilateral cleft in lower lip pit closed in a month after surgery.Conclusion: VWS is generally not known and not always diagnosed. It is peculiar that the cleft palate and lip phenomenon is routinely integrated into the same pedigree. The patient with a lip pit can be thoroughly examined, for example, by revealing the secret shape of the cleft. In this case, the surgical repair was handled simultaneously to both functional and esthetic aspects to achieve satisfying results.

Micah: An International Theological Commentary

Micah: An International Theological Commentary

Van der Woude Syndrome: A Case Report

Among the many disturbances of development and growth that involve the oral and perioral structures, cleft lip and palate is perhaps the commonest. Dental literature is replete with syndromes associated with cleft lip and palate, one of which is Van der Woude syndrome. The characteristics of Van der Woude syndrome is the association of cleft lip and/or palate with distinctive lower lip pits. A case of Van der Woude syndrome in an 11-year-old boy and his sister is presented.

A Novel Van der Woude Syndrome-Causing IRF6 Variant Is Subject to Incomplete Non-sense-Mediated mRNA Decay Affecting the Phenotype of Keratinocytes.

Van der Woude syndrome (VWS) is a genetic syndrome that leads to typical phenotypic traits, including lower lip pits and cleft lip/palate (CLP). The majority of VWS-affected patients harbor a pathogenic variant in the gene encoding for the transcription factor interferon regulatory factor 6 (IRF6), a crucial regulator of orofacial development, epidermal differentiation and tissue repair. However, most of the underlying mechanisms leading from pathogenic IRF6 gene variants to phenotypes observed in VWS remain poorly understood and elusive. The availability of one VWS individual within our cohort of CLP patients allowed us to identify a novel VWS-causing IRF6 variant and to functionally characterize it. Using VWS patient-derived keratinocytes, we reveal that most of the mutated IRF6_VWS transcripts are subject to a non-sense-mediated mRNA decay mechanism, resulting in IRF6 haploinsufficiency. While moderate levels of IRF6_VWS remain detectable in the VWS keratinocytes, our data illustrate that the IRF6_VWS protein, which lacks part of its protein-binding domain and its whole C-terminus, is noticeably less stable than its wild-type counterpart. Still, it maintains transcription factor function. As we report and characterize a so far undescribed VWS-causing IRF6 variant, our results shed light on the physiological as well as pathological role of IRF6 in keratinocytes. This acquired knowledge is essential for a better understanding of the molecular mechanisms leading to VWS and CLP.

Change in Initial Tympanostomy Tube Placement Timing Yields Decreased Burden of Care Without Increased Complications in Patients With Cleft Lip and Palate

To report a practice audit of the consequences of a change in protocol in the timing of placement of tympanostomy tubes in infants with cleft lip and palate. All children with a diagnosis of cleft lip and palate, treated between November 1998 and May 2006 under the old protocol, and between December 2012 and July 2016 under a new protocol. Under the old protocol, tympanostomy tubes were first inserted at the time of lip repair at around age 2 months. Under the new protocol, tympanostomy tubes were deferred until the time of palate repair around the age of 9 months. Children with syndromic diagnoses other than Stickler syndrome and Van der Woude syndrome, and children who failed newborn hearing screen were excluded. Incidence of otorrhea from birth to 6 months after palate repair and presence of hearing loss at ages 1 and 2. Deferral of tympanostomy tubes until the time of palate repair decreases the burden of care due to otorrhea as compared to early tympanostomy tubes at the time of lip repair. There was no significant difference in the incidence of hearing thresholds at or below 15 dB at age 1 or 2. Placement of tympanostomy tubes at the time of palate repair balances the goals of minimizing the adverse effects from middle ear effusion and minimizing the burden of care on our patients and their families.

A clinical and multi‑omics study of Van der Woude syndrome in three generations of a Chinese family.

Previous studies have suggested that pathogenic variants in interferon regulatoryse factor 6 (IRF6) can account for almost 70% of familial Van der Woude Syndrome (VWS) cases. However, gene modifiers that account for the phenotypic variability of IRF6 in the context of VWS remain poorly characterized. The aim of this study was to report a family with VWS with variable expressivity and to identify the genetic cause. A 4-month-old boy initially presented with cleft palate and bilateral lower lip pits. Examination of his family history identified similar, albeit milder, clinical features in another four family members, including bilateral lower lip pits and/or hypodontia. Peripheral blood samples of eight members in this three-generation family were subsequently collected, and whole-exome sequencing was performed to detect pathogenic variants. A heterozygous missense IRF6 variant with a c.1198C>T change in exon 9 (resulting in an R400W change at the amino acid level) was detected in five affected subjects, but not in the other three unaffected subjects. Moreover, subsequent structural analysis was indicative of damaged stability to the structure in the mutant IRF protein. Whole-transcriptome sequencing, expression analysis and Gene Ontology enrichment analysis were conducted on two groups of patients with phenotypic diversity from the same family. These analyses identified significant differentially expressed genes and enriched pathways in these two groups. Altogether, these findings provide insight into the mechanism underlying the variable expressivity of VWS.

Taurodontism in the first permanent molars in Van der Woude syndrome compared to isolated cleft palate.

To analyse prevalence, pattern, and severity of taurodontism in individuals with Van der Woude syndrome (VWS) exhibiting cleft palate and compare with aged-matched non-syndromic cleft palate (NSCP) and non-cleft controls. One hundred and seventy-eight dental panoramic tomographs (DPTs) (105 girls and 73 boys) consisting of 42 VWS patients (x¯=8.55±1.02years), 42 NSCP patients (x¯=8.59±1.02years), and 94 normative non-cleft children (x¯=8.79±1.16years) were assessed and their first permanent molars evaluated. Measurement 3 of the taurodontism index developed by Shifman and Chanannel with the Tulensalo modification was used. Prevalence, pattern, and severity were compared between groups. Statistical differences were determined by one-way analysis of variance and Fisher test. Repeatability was calculated by Cohens Kappa test. The prevalence of taurodontic molars was 59.5% in VWS, 45.2% in NSCP, and 26.6% in non-cleft controls. The prevalence and severity of taurodontism in VWS and NSCP were significantly higher than in non-cleft children in all first permanent molars. There was no significant difference in prevalence and severity between VWS and NSCP. The odds for having taurodontism in the VWS group was approximately double compared to the NSCP group. Most of the taurodontic molars showed hypotaurodontism and taurodontism occurred bilaterally more frequently than unilaterally. This study shows a higher prevalence of taurodontism in VWS and NSCP. Most taurodontic molars are hypotaurodontic and most occur bilaterally.

Non-random distribution of deleterious mutations in the DNA and protein-binding domains of IRF6 are associated with Van Der Woude syndrome.

BackgroundThe development of the face occurs during the early days of intrauterine life by the formation of facial processes from the first Pharyngeal arch. Derangement in these well‐organized fusion events results in Orofacial clefts (OFC). Van der Woude syndrome (VWS) is one of the most common causes of syndromic cleft lip and/or palate accounting for 2% of all cases. Mutations in the IRF6 gene account for 70% of cases with the majority of these mutations located in the DNA‐binding (exon 3, 4) or protein‐binding domains (exon 7–9). The current study was designed to update the list of IRF6 variants reported for VWS by compiling all the published mutations from 2013 to date as well as including the previously unreported VWS cases from Africa and Puerto Rico.MethodsWe used PubMed with the search terms; "Van der Woude syndrome," “Popliteal pterygium syndrome,” "IRF6," and "Orofacial cleft" to identify eligible studies. We compiled the CADD score for all the mutations to determine the percentage of deleterious variants.ResultsTwenty‐one new mutations were identified from nine papers. The majority of these mutations were in exon 4. Mutations in exon 3 and 4 had CADD scores between 20 and 30 and mutations in exon 7–9 had CADD scores between 30 and 40. The presence of higher CADD scores in the protein‐binding domain (exon 7–9) further confirms the crucial role played by this domain in the function of IRF6. In the new cases, we identified five IRF6 mutations, three novel missense mutations (p.Phe36Tyr, p.Lys109Thr, and p.Gln438Leu), and two previously reported nonsense mutations (p.Ser424*and p.Arg250*).ConclusionMutations in the protein and DNA‐binding domains of IRF6 ranked among the top 0.1% and 1% most deleterious genetic mutations, respectively. Overall, these findings expand the range of VWS mutations and are important for diagnostic and counseling purposes.

Functional Characterization of a Novel IRF6 Frameshift Mutation From a Van Der Woude Syndrome Family.

BackgroundLoss-of-function mutations in interferon regulatory factor-6 (IRF6) are responsible for about 70% of cases of Van Der Woude Syndrome (VWS), an autosomal dominant developmental disorder characterized by pits and/or sinuses of the lower lip and cleft lip, cleft palate, or both.MethodsWe collected a Chinese Han VWS pedigree, performed sequencing and screening for the causal gene mutant. Initially, species conservation analysis and homology protein modeling were used to predict the potential pathogenicity of mutations. To test whether a VWS family-derived mutant variant of IRF6 retained function, we carried out rescue assays in irf6 maternal-null mutant zebrafish embryos. To assess protein stability, we overexpressed reference and family-variants of IRF6 in vitro.ResultsWe focused on a VWS family that includes a son with bilateral lip pits, uvula fissa and his father with bilateral cleft lip and palate. After sequencing and screening, a frameshift mutation of IRF6 was identified as the potential causal variant (NM.006147.3, c.1088-1091delTCTA; p.Ile363ArgfsTer33). The residues in this position are strongly conserved among species and homology modeling suggests the variant alters the protein structure. In irf6 maternal-null mutant zebrafish embryos the periderm differentiates abnormally and the embryos rupture and die during gastrulation. Injection of mRNA encoding the reference variant of human IRF6, but not of the frame-shift variant, rescued such embryos through gastrulation. Upon overexpression in HEK293FT cells, the IRF6 frame-shift mutant was relatively unstable and was preferentially targeted to the proteasome in comparison to the reference variant.ConclusionIn this VWS pedigree, a novel frameshift of IRF6 was identified as the likely causative gene variant. It is a lost function mutation which could not rescue abnormal periderm phenotype in irf6 maternal-null zebrafish and which causes the protein be unstable through proteasome-dependent degradation.

SAT0585 GEO-EPIDEMIOLOGY OF AUTOANTIBODIES IN RA: DIFFERENT PREVALENCES IN FOUR ETHNICALLY DIVERSE RA POPULATIONS

Background:Rheumatoid arthritis (RA) has been described in virtually every ethnic population. Most RA patients harbor anti-modified protein antibodies (AMPAs), including anti-citrullinated protein (ACPA), anti-carbamylated protein (anti-CarP), anti-malondialdehyde acetaldehyde (anti-MAA), and anti-acetylated protein antibodies (AAPA). However, it is unclear whether differences exist in the AMPA response between different ethnic groups. Such differences could provide new clues to genetic and environmental factors contributing to autoantibody development.Objectives:To investigate the prevalence of different AMPA in four ethnically diverse RA populations, and their association with smoking.Methods:Enzyme-linked immunosorbent assays were used to measure anti-CarP IgG, anti-MAA IgG (both in-house), and anti-acetylated vimentin IgG (Orgentec) in ACPA-positive sera of Dutch (NL, n=103), Japanese (JP, n=174), Canadian First Nations People (FN, n=100), and black South Africans (SA, n=67) fulfilling the 1987 ACR classification criteria for RA. Ethnicity-matched local healthy controls were used to calculate cohort-specific cut-offs. Logistic regression was used to identify whether ever-smoking was associated with AMPA seropositivity in each cohort, corrected for age, gender, and disease duration. Random-effects meta-analysis was used to pool the resulting odds ratios (OR).Results:For all three AMPAs, median levels were higher in FN and especially SA than NL and JP patients (Figure 1). The median autoantibody levels in arbitrary units (in % of patients positive) for NL, JP, FN and SA RA patients were: anti-CarP IgG: 1157 (47%), 994 (43%), 1642 (58%) and 2336 (76%) (p<0.001); anti-MAA IgG: 131 (29%), 179 (22%), 251 (29%) and 257 (53%) (p<0.001); AAPA: 133 (20%), 136 (17%), 153 (38%) and 316 (28%) (p<0.001). Prevalence, meaning positivity, also differed significantly between cohorts for all AMPAs (p<0.001).There were also marked differences in total IgG levels in mean (SD) g/L: 13 (4) for NL, 17 (6) for JP, 18 (6) for FN, and 25 (8) for SA (p<0.001). When the autoantibody levels were normalized to total IgG, the differences in became less pronounced between cohorts (Figure 2). The median arbitrary units per g/L Total IgG for NL, JP, FN and SA RA patients were: anti-CarP IgG: 54, 25, 53, and 79; anti-MAA IgG: 6, 5, 8, and 9; and AAPA: 2, 2, 2, and 3, suggesting that autoantibody level differences may partly correspond to cohort-specific differences in total IgG, although the overall trend of higher levels in SA persisted. There was no association between smoking and anti-CarP or anti-MAA positivity, with pooled OR (95% CI) of 1.31 (0.79-2.18) and 0.85 (0.46-1.56), respectively. However, smoking was positively and consistently associated with AAPA positivity in each cohort: pooled OR (95% CI) of 2.01 (1.06-3.81).Conclusion:In these ACPA-positive ethnically diverse RA populations, levels and prevalence of various AMPAs differ, suggesting that ethnic background and environment may influence the development of the autoantibody response in RA. Despite these differences, our results imply smoking as a consistent risk factor for AAPA across different ethnic backgrounds.Disclosure of Interests:Emma C. de Moel: None declared, Veerle Derksen: None declared, Leendert A Trouw: None declared, Chikashi Terao: None declared, Mohammed Tikly: None declared, Hani El-Gabalawy: None declared, Holger Bang Grant/research support from: Employee of Orgentec Diagnostika, Thomas Huizinga Grant/research support from: Ablynx, Bristol-Myers Squibb, Roche, Sanofi, Consultant of: Ablynx, Bristol-Myers Squibb, Roche, Sanofi, Rene Toes: None declared, Diane van der Woude: None declared

Chemoprevention of keratinocyte carcinoma and actinic keratosis in solid-organ transplant recipients: Systematic review and meta-analyses

To the Editor: Skin cancers account for 40% of malignancies in solid-organ transplant recipients (SOTRs), who have an 80-fold increased risk of squamous cell carcinoma (SCC) and a 16-fold increased risk of basal cell carcinoma (BCC). Systemic chemoprevention is one method to mitigate this amplified risk. Acitretin, for instance, has been used to prevent keratinocyte carcinomas (KC) and actinic keratoses (AK) in SOTRs since 1995,1Bavinck J.N. Tieben L.M. Van der Woude F.J. et al.Prevention of skin cancer and reduction of keratotic skin lesions during acitretin therapy in renal transplant recipients: a double-blind, placebo-controlled study.J Clin Oncol. 1995; 13: 1933-1938Crossref PubMed Google Scholar but its adverse effects include mucositis, liver and lipid abnormalities, and teratogenicity.2George R. Weightman W. Russ G.R. et al.Acitretin for chemoprevention of non-melanoma skin cancers in renal transplant recipients.Australas J Dermatol. 2002; 43: 269-273Crossref PubMed Scopus (130) Google Scholar Nicotinamide, an amide form of vitamin B3, is a newer chemoprophylaxis with fewer adverse effects.3Chen A.C. Martin A.J. Dalziell R.A. et al.A phase II randomized controlled trial of nicotinamide for skin cancer chemoprevention in renal transplant recipients.Br J Dermatol. 2016; 175: 1073-1075Crossref PubMed Scopus (61) Google Scholar Here we report results of a pairwise and network meta-analyses to summarize the current evidence regarding chemoprevention. We selected studies that analyzed the efficacy of systemic chemoprevention to prevent KC/AK in patients who are SOTRs or have a history of 2 or more KCs, or both. We limited our search to placebo-controlled, randomized control trials (RCTs) that reported the number of new KC/AK in both arms. Two authors (L.Y.T., S.Y.C.T.) independently conducted the literature search, screened titles and abstracts for eligibility, and extracted data. Statistical synthesis was performed with RevMan 5.3 software (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark). After the literature search, 6 RCTs with 734 patients were included in the quantitative synthesis (Appendix A, available via Mendeley at https://doi.org/10.17632/m6z2fzkkxn.2). Of the 6 RCTs, 3 studies with 580 patients (range, 17-192 patients) compared nicotinamide to placebo, and 3 studies with 154 patients (range, 19-35 patients) compared acitretin to placebo. Pairwise meta-analysis of all 6 RCTs using a random-effects model demonstrated a significant risk reduction with chemoprevention (Fig 1). The overall mean difference was 0.855 (95% confidence interval, 0.365-1.345; P < .001). In addition, acitretin and nicotinamide were both efficacious, with a combined mean difference of 0.792 (95% confidence interval, 0.298-1.286; P = .00168) for acitretin and a combined mean difference of 4.239 (95% confidence interval, 0.611-7.866; P = .0220) for nicotinamide. A network meta-analysis comparing nicotinamide and acitretin found no significant difference between the 2 treatments (Fig 2, Appendix B).Fig 1Forest plot of the pairwise meta-analysis of randomized controlled trials. The squares indicate the mean difference and are proportional to the weights used in the meta-analysis. The horizontal lines represent the 95% confidence interval (CI). The diamond indicates the weighted mean difference, and the lateral tips of the diamond indicate the associated 95% CI.View Large Image Figure ViewerDownload Hi-res image Download (PPT)Fig 2Network graph and league table of the network meta-analysis. Mean differences and 95% confidence intervals are calculated using a random-effects model. A mean difference >1 means the top-left treatment is better.View Large Image Figure ViewerDownload Hi-res image Download (PPT) This meta-analysis does not address the optimal dosages of the drugs or the frequency of adverse effects. In addition, owing to the limited numbers of eligible RCTs, we are unable to investigate how chemoprevention is influenced by the duration or type of transplantation, duration of systemic chemoprevention, or existing immunosuppressive regimens. Moving forward, topical chemoprevention may be a suitable alternative to systemic chemoprophylaxis in SOTRs. Notably, large RCTs have evaluated topical chemoprevention for actinic keratosis. For instance, the Veterans Affairs Keratinocyte Carcinoma Chemoprevention trial found that topical 5% 5-fluorouracil cream resulted in a 49% relative risk reduction in the number of AK after 6 months and reduced the risk of SCC requiring surgery by 75% after 1 year but did not lower the risk of BCC.4Hyemin P. Hogan D. Eilers D. et al.Long-term efficacy of topical fluorouracil cream 5% for treating actinic keratosis: a randomized clinical trial.JAMA Dermatol. 2015; 151: 952-960Crossref PubMed Scopus (69) Google Scholar,5Weinstock M.A. Thwin S.S. Siegel J.A. et al.Chemoprevention of basal and squamous cell carcinoma with a single course of fluorouracil, 5%, cream: a randomized clinical trial.JAMA Dermatol. 2018; 154: 167-174Crossref PubMed Scopus (54) Google Scholar To our knowledge, this is the first meta-analysis that statistically integrates the current evidence regarding chemoprevention of KC/AK. This study demonstrates that systemic chemoprevention with nicotinamide or acitretin is effective in lowering the risk of KC/AK. Yet, even with the advent of better chemoprevention, regular physician surveillance and sun protection are still key basic strategies that should be practiced by all SOTRs.

Regulation of cranial neural crest cell fate by Irf6 and Twist1 interaction

A wide variety of common craniofacial birth defects and pediatric cancers arise from errors in the development of cranial neural crest cells (CNCC) that give rise to craniofacial skeletal and peripheral nervous systems. Identification of the genetic and environmental factors that regulate cell fate of CNCCs is crucial for uncovering the causes behind craniofacial disorders. Our lab has identified a dual‐transcription factor pathway that regulates CNCCs during EMT and migration. Initially, we identified a causative mutation in a TWIST1 binding site within an Interferon Regulatory Factor 6 (IRF6) enhancer in a multi‐generational family affected with syndromic cleft lip and palate called Van der Woude syndrome. Our subsequent animal work has shown that Twist1 and Irf6 genetically interact during early craniofacial development, and that the compound heterozygotes exhibit craniofacial abnormalities. We recently demonstrated that Irf6 is required for neural tube and CNCC development and that it interacts with Twist1 during EMT and migration of CNCCs. We also showed that TWIST1 is highly phosphorylated in CNCCs and its phosphorylation is crucial for regulating Irf6 and potentially miR10 family members in CNCC‐derived craniofacial tissues. Our recent in‐vivo and neural tube explants using dual fluorescent cell tracing system showed that Twist1 conditional knockout (CKO) in CNCCs significantly reduced cell delamination and disrupted EMT. The detached Twist1 CKO in CNCCs retained their epithelial signatures and migrated as clusters of epithelial‐like cells over significantly shorter distances. Finally, Twist1 phospho‐incompetent mice for two serine residues were recently generated to determine their impact on TWIST1 activity. Our preliminary results showed that Twist1S68A/S68A phospho‐mutant mice have craniofacial bone defects and forebrain hemorrhage.Support or Funding InformationUTHealth start‐up funds and a small grant from theRolanette and Berdon Lawrence Bone Disease Program of Texas

Case Report: Congenital absence of uvula and trismus - a rare presentation of Van der Woude syndrome

Van der Woude syndrome (VWS) is the most common single gene mutation causing cleft lip/palate, responsible for approximately 2% of all cases. Inherited in an autosomal dominant pattern, VWS occurs at an incidence of 1 in 35,000 to 100,000. The most commonly reported manifestations of VWS is lip pits, cleft lip or palate. We present a case of a 34-week infant with unique and rarely reported symptoms of VWS, such as trismus and absent uvula.

Epithelial Migration and Non-adhesive Periderm Are Required for Digit Separation during Mammalian Development.

The fusion of digits or toes, syndactyly, can be part of complex syndromes, including van der Woude syndrome. A subset of van der Woude cases is caused by dominant-negative mutations in the epithelial transcription factor Grainyhead like-3 (GRHL3), and Grhl3-/-mice have soft-tissue syndactyly. Although impaired interdigital cell death of mesenchymal cells causes syndactyly in multiple genetic mutants, Grhl3-/- embryos had normal interdigital cell death, suggesting alternative mechanisms for syndactyly. We found that in digit separation, the overlying epidermis forms a migrating interdigital epithelial tongue (IET) when the epithelium invaginates to separate the digits. Normally, the non-adhesive surface periderm allows the IET to bifurcate as the digits separate. In contrast, in Grhl3-/- embryos, the IET moves normally between the digits but fails to bifurcate because of abnormal adhesion of the periderm. Our study identifies epidermal developmental processes required for digit separation.

Introduction: Evolution of inflammatory arthritis from innate to adaptive immune mechanisms.

Introduction: Evolution of inflammatory arthritis from innate to adaptive immune mechanisms.