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Objective: Van der Woude syndrome is characterized by the concurrence of cleft lip and palate with lower lip fistulas. During fistula resection, care must be taken to maintain the function of the orbicularis oris and restore the normal shape of the lips. Several reports have documented various resection methods; however, the most appropriate surgical resection is controversial. In this report, lower lip fistulas were resected using an inverted‐T surgical design. Methods: Of the six patients with Van der Woude syndrome who underwent resection of the lower lip fistula in our department between January 2007 and December 2015, three patients who underwent inverted‐T lip reduction were included. The postoperative position‐dependent morphology of the fistulas was examined. Results: Five years postoperatively, no complications such as postoperative infections, mucous retention cyst formation, a dysmorphic appearance of the lip, or fistula recurrence were observed. Moreover, a stable wound morphology was evident. Conclusions: The inverted‐T lip reduction seems to be promising technique for the excision of lower lip fistulas in patients with Van der Woude syndrome, yielding good results. [ABSTRACT FROM AUTHOR]

Background: To date, there are over 320 variants identified in the IRF6 gene that cause Van der Woude syndrome or popliteal pterygium syndrome. We sequenced this gene in a South African orofacial cleft cohort to identify the causal IRF6 variants in our population. Method: Saliva samples from 100 patients with syndromic and non‐syndromic CL ± P were collected. Patients were recruited from the cleft clinics at two public, tertiary hospitals in Durban, South Africa (SA), namely Inkosi Albert Luthuli Central Hospital (IALCH) and KwaZulu‐Natal Children's Hospital (KZNCH). We prospectively sequenced the exons of IRF6 in 100 orofacial cleft cases, and where possible, we also sequenced the parents of the individuals to determine the segregation pattern. Results: Two variants were identified; one novel (p.Cys114Tyr) and one known (p.Arg84His) missense variant in IRF6 gene were identified. The patient with the p.Cys114Tyr variant was non‐syndromic with no clinical VWS phenotype expected of individuals with IRF6 coding variants, and the patient with the p.Arg84His had phenotypic features of popliteal pterygium syndrome. The p.Arg84His variant segregated in the family, with the father also being affected. Conclusions: This study provides evidence that IRF6 variants are found in the South African population. Genetic counselling is essential for affected families, particularly in the absence of a known clinical phenotype since it helps with the plans for future pregnancies. [ABSTRACT FROM AUTHOR]

Aim: To describe the particular craniofacial characteristics of Van der Woude syndrome(VWS) patients compared to patients with a non‐syndromic cleft (CG1) and to a malocclusive healthy population (CG2). Material and methods: Retrospective case‐control study. A sample of 110 matched‐patients was recruited (VWS (n = 7), CG1 (n = 49), CG2 (n = 49)). Subsequently, 37 radiometric variables were analysed and the dental‐skeletal ages were determined. The intra/inter‐observer method errors were quantified. Descriptive statistics were computed, and different inferential analysis tests were used depending on the normality of the data (Chi‐square test, Fisher's exact test, paired Student's T‐test, Mann–Whitney U test) (p‐value < 0.05). Pairwise comparisons were corrected by Bonferroni's criteria. Results: VW‐patients presented specific craniofacial characteristics and morphology. A marked tendency to the vertical growth pattern was found in VW‐patients compared to CG1‐CG2 (p < 0.001); at the sagittal level, skeletal class II caused by mandibular retrognathism, with a greatly increased ANB angle compared to CG1 (p = 0.042). Dental analysis showed that the lower incisor was more retruded and retroclined (p < 0.05 in all cases) and the interincisal angulation was increased (p < 0.001 (CG2)). At the profile level, an open nasolabial angle (p = 0.040; CG1) and a more protruding lower lip with respect to the Sn‐Pg plane (p = 0.040 (CG1); p = 0.044 (CG2)) were observed. Conclusions: VW‐patients present particular characteristics in the facial skeletal structures. There is a critical necessity to increase the evidence regarding specific clinical features and orofacial pathology of rare diseases such as VWS, which will help to these minorities to gain access in the future to a better quality of care with precise treatment and diagnostic necessities. [ABSTRACT FROM AUTHOR]

Background: The 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. Methods: We 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. Results: Twenty‐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*). Conclusion: Mutations 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. [ABSTRACT FROM AUTHOR]

Background: Interferon Regulatory Factor 6 (IRF6) gene encodes a member of the IRF family of transcription factors. Mutations in IRF6 cause Van der Woude Syndrome (VWS), which is the most common malformation of syndromic orofacial clefts in humans. Methods: Here, we performed sequencing studies of six families with VWS in the Chinese Han population. The entire IRF6‐coding region and the exon–intron boundaries including exons 3–8 and part of exon 9 were screened among all the collected family members by Sanger sequencing. Results: We found a novel splice site variant c.175‐6T>A, two novel missense variants (p.Lys66Arg and p.Pro107Thr), in addition with a previously reported missense variant (p.Leu87Phe), which were all located in and nearby exon 4 of IRF6. Meanwhile, a novel frameshift variant p.G257Vfs*46 in exon 7 of IRF6 was also detected. All the mutations presented to be co‐segregated in each family. Conclusion: Our study has advanced the understanding of the genetic architecture of VWS and provides the basis for genetic counseling, antenatal diagnosis, and gene therapy of high risk groups. [ABSTRACT FROM AUTHOR]

Background: Van der Woude syndrome (VWS) is the most common form of syndromic orofacial cleft caused predominantly by mutations in Interferon Regulatory Factor 6 (IRF6). We previously reported that individuals with VWS have increased risk of wound healing complications following cleft repair compared with individuals with nonsyndromic orofacial clefts (nonsyndromic cleft lip and palate—NSCLP). In vitro, absence of IRF6 leads to impaired keratinocyte migration and embryonic wound healing. However, there is currently no data on tissue repair in adult animals and cells with reduced levels of IRF6 like in VWS. Results: Excisional wounds of Irf6+/− and wild‐type animals were analyzed 4 and 7 days post‐wounding. Although all wounds were reepithelialized after 7 days, the epidermal and wound volume of repaired wounds was larger in Irf6+/−. These data were supported by increased keratinocyte proliferation in the neoformed epidermis and a less mature granulation tissue with increased cytokine levels. This effect was not cell autonomous, as Irf6+/− neonatal keratinocytes in vitro did not exhibit defects in scratch wound closure or proliferation. Keratinocytes from individuals with VWS also migrated similarly to keratinocytes from NSCLP individuals. Conclusions: These data support a role for IRF6 in wound healing by regulating keratinocyte proliferation, granulation tissue maturation, and cytokine levels. Key Findings: Mice heterozygous for Irf6 have altered wound healing in vivo with increased epidermal volume and wound volume.The defect is likely due to increased proliferation in the newly formed epidermis and some persistence of myofibroblasts in the granulation tissue.Cytokine levels were upregulated in Irf6+/‐ compared to wild type mice.Neither proliferation nor migration of Irf6+/‐ keratinocytes in vitro was altered, suggesting a non‐cell autonomous effect.Cells from individuals with IRF6 mutations closed an in vitro scratch wound similarly to cells from individuals with NSCLP. [ABSTRACT FROM AUTHOR]

Van der Woude syndrome (VWS) is an autosomal dominant disorder with a rare clinical manifestation of orofacial disorders with deletion in the 1q32‐q41 chromosome band. In our study we present a clinical case of a 1‐year old boy with a bilateral cleft lip, a cleft palate and bilateral congenital pits on the lower lip and a father with various clinical presentations of VWS. [ABSTRACT FROM AUTHOR]

Background: Mutations in IRF6, CHUK (IKKA), and RIPK4 can lead to a disease spectrum that includes cutaneous, limb, and craniofacial malformations. Loss of these alleles in the mouse leads to perinatal lethality and severe cutaneous, limb, and craniofacial defects also. Genetic rescue in the mouse has been shown for Ikka and Ripk4. Results: Here, we show partial genetic rescue of Irf6 knockout embryos using the KRT14 promoter to drive Irf6 expression in the basal epithelium. In contrast to Irf6 knockout embryos, rescue embryos survive the immediate perinatal period. Macroscopic examination reveals rescue of skin adhesions between the axial and appendicular skeleton. Unexpectedly, KRT14-driven Irf6 expression does not completely rescue orofacial clefting and adhesions between the palate and tongue, suggesting the importance of cell-autonomous IRF6 expression in periderm. Like knockout embryos, Irf6 rescue embryos also have persistent esophageal adhesions, which likely contribute to postnatal demise. Conclusions: Together, these data suggest that targeted expression of IRF6 can significantly reduce disease severity, but that a minimum level of Irf6 in both periderm and basal epithelial cells is necessary for orofacial development. Therefore, homologous human and mouse phenotypes are observed for IRF6, IKKA, and RIPK4. In this work, we show that altering the expression level of IRF6 dramatically modified this phenotype in utero. Developmental Dynamics 246:670-681, 2017. © 2017 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Background Orofacial clefts are congenital malformations of the orofacial region, with a global incidence of one per 700 live births. Interferon Regulatory Factor 6 ( IRF6) ( OMIM:607199) gene has been associated with the etiology of both syndromic and nonsyndromic orofacial clefts. The aim of this study was to show evidence of potentially pathogenic variants in IRF6 in orofacial clefts cohorts from Africa. Methods We carried out Sanger Sequencing on DNA from 184 patients with nonsyndromic orofacial clefts and 80 individuals with multiple congenital anomalies that presented with orofacial clefts. We sequenced all the nine exons of IRF6 as well as the 5′ and 3′ untranslated regions. In our analyses pipeline, we used various bioinformatics tools to detect and describe the potentially etiologic variants. Results We observed that potentially etiologic exonic and splice site variants were nonrandomly distributed among the nine exons of IRF6, with 92% of these variants occurring in exons 4 and 7. Novel variants were also observed in both nonsyndromic orofacial clefts (p.Glu69Lys, p.Asn185Thr, c.175-2A>C and c.1060+26C>T) and multiple congenital anomalies (p.Gly65Val, p.Lys320Asn and c.379+1G>T) patients. Our data also show evidence of compound heterozygotes that may modify phenotypes that emanate from IRF6 variants. Conclusions This study demonstrates that exons 4 and 7 of IRF6 are mutational 'hotspots' in our cohort and that IRF6 mutants-induced orofacial clefts may be prevalent in the Africa population, however, with variable penetrance and expressivity. These observations are relevant for detection of high-risk families as well as genetic counseling. In conclusion, we have shown that there may be a need to combine both molecular and clinical evidence in the grouping of orofacial clefts into syndromic and nonsyndromic forms. [ABSTRACT FROM AUTHOR]

Background Single genetic variants can affect multiple tissues during development. Thus it is possible that disruption of shared gene regulatory networks might underlie syndromic presentations. In this study, we explore this idea through examination of two critical developmental programs that control orofacial and neural tube development and identify shared regulatory factors and networks. Identification of these networks has the potential to yield additional candidate genes for poorly understood developmental disorders and assist in modeling and perhaps managing risk factors to prevent morbidly and mortality. Methods We reviewed the literature to identify genes common between orofacial and neural tube defects and development. We then conducted a bioinformatic analysis to identify shared molecular targets and pathways in the development of these tissues. Finally, we examine publicly available RNA-Seq data to identify which of these genes are expressed in both tissues during development. Results We identify common regulatory factors in orofacial and neural tube development. Pathway enrichment analysis shows that folate, cancer and hedgehog signaling pathways are shared in neural tube and orofacial development. Developing neural tissues differentially express mouse exencephaly and cleft palate genes, whereas developing orofacial tissues were enriched for both clefting and neural tube defect genes. Conclusion These data suggest that key developmental factors and pathways are shared between orofacial and neural tube defects. We conclude that it might be most beneficial to focus on common regulatory factors and pathways to better understand pathology and develop preventative measures for these birth defects. Birth Defects Research 109:169-179, 2017. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Patients with Van der Woude syndrome typically present with cleft lip, cleft lip and palate, or with cleft palate only. In contrast to non-syndromic cleft lip and/or palate, Van der Woude syndrome typically is characterized by bilateral, paramedian lower-lip pits. Popliteal pterygium syndrome shares features with Van der Woude syndrome, but, in addition, is characterized by a popliteal pterygium, genital anomalies, cutaneous syndactyly of the fingers and the toes, and a characteristic pyramidal fold of skin overlying the nail of the hallux. In some patients oral synechiae or eyelid synechiae are present. Van der Woude Syndrome and Popliteal pterygium syndrome are autosomal dominantly inherited disorders caused by heterozygous mutations in IRF6. We present a three generation family with tremendous intrafamilial phenotypic variability. The newborn index patient had a diagnosis of Popliteal pterygium syndrome. The mother presented with a classic Van der Woude Syndrome, while the maternal grandfather had Van der Woude Syndrome as well as minor signs of Popliteal pterygium syndrome. In all three affecteds the known pathogenic mutation c.265A>G, p.Lys89Glu in IRF6 was identified. While inter- as well as intra-familial variability has been described in IRF6-related disorders, the occurrence of a typical Van der Woude Syndrome without any other anomalies as well as a diagnosis of Popliteal pterygium syndrome in the same family is rare. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Van der Woude syndrome ( VWS) is an autosomal dominant malformation syndrome characterized by orofacial clefting ( OFC) and lower lip pits. The clinical presentation of VWS is variable and can present as an isolated OFC, making it difficult to distinguish VWS cases from individuals with non-syndromic OFCs. About 70% of causal VWS mutations occur in IRF6, a gene that is also associated with non-syndromic OFCs. Screening for IRF6 mutations in apparently non-syndromic cases has been performed in several modestly sized cohorts with mixed results. In this study, we screened 1521 trios with presumed non-syndromic OFCs to determine the frequency of causal IRF6 mutations. We identified seven likely causal IRF6 mutations, although a posteriori review identified two misdiagnosed VWS families based on the presence of lip pits. We found no evidence for association between rare IRF6 polymorphisms and non-syndromic OFCs. We combined our results with other similar studies (totaling 2472 families) and conclude that causal IRF6 mutations are found in 0.24-0.44% of apparently non-syndromic OFC families. We suggest that clinical mutation screening for IRF6 be considered for certain family patterns such as families with mixed types of OFCs and/or autosomal dominant transmission. [ABSTRACT FROM AUTHOR]

Orofacial clefting is a common birth defect with significant morbidity. A panoply of candidate genes have been discovered through synergy of animal models and human genetics. Among these, variants in interferon regulatory factor 6 ( IRF6) cause syndromic orofacial clefting and contribute risk toward isolated cleft lip and palate (1/700 live births). Rare variants in IRF6 can lead to Van der Woude syndrome (1/35,000 live births) and popliteal pterygium syndrome (1/300,000 live births). Furthermore, IRF6 regulates GRHL3 and rare variants in this downstream target can also lead to Van der Woude syndrome. In addition, a common variant (rs642961) in the IRF6 locus is found in 30% of the world's population and contributes risk for isolated orofacial clefting. Biochemical studies revealed that rs642961 abrogates one of four AP-2alpha binding sites. Like IRF6 and GRHL3, rare variants in TFAP2A can also lead to syndromic orofacial clefting with lip pits (branchio-oculo-facial syndrome). The literature suggests that AP-2alpha, IRF6 and GRHL3 are part of a pathway that is essential for lip and palate development. In addition to updating the pathways, players and pursuits, this review will highlight some of the current questions in the study of orofacial clefting. Developmental Dynamics 245:220-232, 2016. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Clefts of the lip and/or palate (CLP) are oral-facial defects that affect health and overall quality of life. CLP patients often need multidisciplinary treatment to restore oral function and esthetics. This paper describes the oral rehabilitation of a CLP adult patient who had maxillary bone and tooth loss, resulting in decreased occlusal vertical dimension. Functional and cosmetic rehabilitation was achieved using a maxillary removable partial denture (RPD) attached to telescopic crowns. Attachment-retained RPDs may be a cost-effective alternative for oral rehabilitation in challenging cases with substantial loss of oral tissues, especially when treatment with fixed dental prostheses and/or dental implants is not possible. [ABSTRACT FROM AUTHOR]

The role of interferon regulatory factor 6 ( IRF6) gene mutations in causing Van der Woude syndrome ( VWS) and poplyteal pterygium syndrome has been described in different populations worldwide. The former is one of the major syndromes of cleft lip and/or cleft palate (CL/P) with the distinct phenotype of presence of pits with or without sinuses on the lower lip. We identified seven probands with VWS from Punjab province of Pakistan and recognized two previously unreported lip pit phenotypes. The mutational analysis of IRF6 in this cohort revealed four novel and two previously reported mutations. The newly identified mutations include three frameshifts (c. 635delG; c.21_33del13; c. 627delC) and one transition mutation (c.2T>C) affecting the first codon of IRF6. Together with a past epidemiological study on VWS in Pakistan, the frequency of this syndrome among CL/P individuals from Punjab was calculated to be 1.17%. [ABSTRACT FROM AUTHOR]

Orofacial clefts ( OFC) are complex genetic traits that are often classified as syndromic or nonsyndromic clefts. Currently, there are over 500 types of syndromic clefts in the Online Mendelian Inheritance in Man ( OMIM) database, of which Van der Woude syndrome ( VWS) is one of the most common (accounting for 2% of all OFC). Popliteal pterygium syndrome ( PPS) is considered to be a more severe form of VWS. Mutations in the IRF6 gene have been reported worldwide to cause VWS and PPS. Here, we report studies of families with VWS and PPS in sub-Saharan Africa. We screened the DNA of eight families with VWS and one family with PPS from Nigeria and Ethiopia by Sanger sequencing of the most commonly affected exons in IRF6 (exons 3, 4, 7, and 9). For the VWS families, we found a novel nonsense variant in exon 4 (p.Lys66X), a novel splice-site variant in exon 4 (p.Pro126Pro), a novel missense variant in exon 4 (p.Phe230Leu), a previously reported splice-site variant in exon 7 that changes the acceptor splice site, and a known missense variant in exon 7 (p.Leu251Pro). A previously known missense variant was found in exon 4 (p.Arg84His) in the PPS family. All the mutations segregate in the families. Our data confirm the presence of IRF6-related VWS and PPS in sub-Saharan Africa and highlights the importance of screening for novel mutations in known genes when studying diverse global populations. This is important for counseling and prenatal diagnosis for high-risk families. [ABSTRACT FROM AUTHOR]

Van der Woude syndrome (VWS) is a rare autosomal dominant condition with high penetrance and variable expression. Clinical manifestation of this autosomal dominant clefting syndrome includes bilateral midline lower lip pits, cleft lip, and cleft palate along with hypodontia. These congenital lip pits appear as a malformation in the vermilion border of the lip, with or without excretion. Discomfort caused by spontaneous or induced drainage of saliva/mucus when pressure is applied or during a meal as well as poor aesthetic match is one of the main complaints of patients with congenital lip fistula. The pits are treated by surgical resection. Dentists should be aware of the congenital lip pits as in Van der Woude syndrome because they have been reported to be associated with a variety of malformations or other congenital disorders. Here, the authors report a rare case of Van der Woude syndrome with short review of the literature. [ABSTRACT FROM AUTHOR]

Malik S, Kakar N, Hasnain S, Ahmad J, Wilcox ER, Naz S. Epidemiology of Van der Woude syndrome from mutational analyses in affected patients from Pakistan. Mutations in IRF6 cause Van der Woude syndrome (VWS), one of the most common syndromes associated with cleft lip (CL) with or without cleft palate (CP). The presence of pits on the lower lip of patients is the most characteristic feature of the syndrome. We have identified three novel and seven previously reported IRF6 mutations in 12 of 16 unrelated families segregating VWS from Pakistan. The three newly identified mutations include a frameshift (c.568delG) and two missense mutations c.295G>A (p.G99S) and c.1219T>C (p.S407P). Recent functional studies on IRF6 and the three-dimensional structure of IRF5 carboxy (C) terminus, a protein encoded by a paralog of IRF6, shed light on the p.S407P substitution. Additionally, the identification of the same mutations responsible for VWS in Pakistan, as reported in other global populations worldwide, marks these residues as mutational hotspots and indicates their essential role in structural stability or function of IRF6. This is the first study of VWS in Pakistan and we estimate that 1 in 100 patients with CL with or without CP (CL/P) are affected in the Pakistani population predominantly from the Punjab area. [ABSTRACT FROM AUTHOR]

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Van der Woude syndrome (VWS) is an autosomal dominant disorder manifested in cleft lip and/or palate and lip pits. Isolated clefts of the lip and/or palate (ICLP) have both genotype and phenotype overlap with VWS. Subjects with ICLP have abnormalities in brain structure and function. Given the similarities between VWS and ICLP, the current study was designed to evaluate the pattern of brain structure of adults with VWS. Fourteen adults with VWS were compared to age- and gender-matched healthy controls. Brain structure was evaluated using magnetic resonance imaging. All subjects with VWS had enlarged volumes of the anterior regions of the cerebrum. Men with VWS had reduced volumes of the posterior cerebrum. Anterior cerebrum volume was negatively correlated with intelligent quotient in the subjects with VWS indicating that the enlargement of this brain region was ‘pathologic.’ The pattern of brain structure in VWS is nearly identical to those seen in ICLP. In addition, men are affected more severely. Pathologic enlargement of the tissue and a gender effect with men affected more severely are common features of neurodevelopmental disorders supporting the notion that the brain structure of VWS and ICLP may be because of abnormal brain development. [ABSTRACT FROM AUTHOR]

Van der Woude syndrome (VWS) is usually underreported and frequently not diagnosed. The phenomenon that cleft lip and palate are regularly combined in the same pedigreemakes it unique. A meticulous examination of a patient with lip pitsmay reveal a hidden form of a cleft, for example, submucous. This paper presents a case of VWS in a ten-year-old boy with characteristic orofacial features. Special emphasis has also been given on the need for appropriate genetic counseling. [ABSTRACT FROM AUTHOR]

The Van der Woude syndrome is a rare autosomal dominant developmental malformation usually associated with bilateral lower lip pits. These congenital lip pits appear clinically as a malformation in the vermilion border of the lip, with or without excretion. As a genetic defect has been identified as a microdeletion of chromosome bands 1q32–q41, genetic counselling of patients may be considered. A nonsense mutation in the interferon regulatory factor-6 (IRF-6) is discussed as a pathogenic relevant factor. Therapeutic intervention is generally not necessary, although surgical excision is especially indicated in patients with recurrent inflammation. Physicians should be aware of the Van der Woude syndrome because it has been reported to be associated with a variety of malformations or other congenital disorders. [ABSTRACT FROM AUTHOR]