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Nager syndrome is a rare human developmental disorder characterized by hypoplastic neural crest-derived craniofacial bones and limb defects. Mutations in SF3B4 gene, which encodes a component of the spliceosome, are a major cause for Nager. A review of the literature indicates that 45% of confirmed cases are also affected by conductive, sensorineural or mixed hearing loss. Conductive hearing loss is due to defective middle ear ossicles, which are neural crest derived, while sensorineural hearing loss typically results from defective inner ear or vestibulocochlear nerve, which are both derived from the otic placode. Animal model of Nager syndrome indicates that upon Sf3b4 knockdown cranial neural crest progenitors are depleted, which may account for the conductive hearing loss in these patients. To determine whether Sf3b4 plays a role in otic placode formation we analyzed the impact of Sf3b4 knockdown on otic development. Sf3b4-depleted Xenopus embryos exhibited reduced expression of several pan-placodal genes six1, dmrta1 and foxi4.1. We confirmed the dependence of placode genes expression on Sf3b4 function in animal cap explants expressing noggin, a BMP antagonist critical to induce placode fate in the ectoderm. Later in development, Sf3b4 morphant embryos had reduced expression of pax8, tbx2, otx2, bmp4 and wnt3a at the otic vesicle stage, and altered otic vesicle development. We propose that in addition to the neural crest, Sf3b4 is required for otic development, which may account for sensorineural hearing loss in Nager syndrome., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2021. Published by Elsevier Inc.)

The nucleoli are membrane-less nuclear substructures that govern ribosome biogenesis and participate in multiple other cellular processes such as cell cycle progression, stress sensing, and DNA damage response. The proper functioning of these organelles is ensured by specific proteins that maintain nucleolar structure and mediate key nucleolar activities. Among all nucleolar proteins, treacle encoded by TCOF1 gene emerges as one of the most crucial regulators of cellular processes. TCOF1 was initially discovered as a gene involved in the Treacher Collins syndrome, a rare genetic disorder characterized by severe craniofacial deformations. Later studies revealed that treacle regulates ribosome biogenesis, mitosis, proliferation, DNA damage response, and apoptosis. Importantly, several reports indicate that treacle is also involved in cancer development, progression, and response to therapies, and may contribute to other pathologies such as Hirschsprung disease. In this manuscript, we comprehensively review the structure, function, and the regulation of TCOF1 /treacle in physiological and pathological processes.

Polydactyly and syndactyly are digital abnormalities in limb-associated birth defects usually caused by genetic disorders. In this study, a five-generation Chinese pedigree was found with triphalangeal thumb polysyndactyly syndrome (TPTPS), showing an autosomal dominant pattern of inheritance. We utilized linkage analysis and whole genome sequencing (WGS) for the genetic diagnosis of this pedigree. Linkage analysis was performed using a genome-wide single nucleotide polymorphism (SNP) chip and three genomic regions were identified in chromosomes 2, 6, and 7 with significant linkage signals. WGS discovered a copy number variation (CNV) mutation caused by a large duplication region at the tail of chromosome 7 located in exons 1-5 of the LMBR1 gene, including the zone of polarizing activity regulatory sequence (ZRS), with a length of approximately 180 kb. A real-time polymerase chain reaction (PCR) assay confirmed the duplication. The findings of our study supported the notion that large duplications including the ZRS caused TPTPS. Our study showed that linkage analysis in combination with WGS could successfully identify the disease locus and causative mutation in TPTPS, which could help elucidate the molecular mechanisms and genotype-phenotype correlations in polydactyly., (© 2020 Wiley Periodicals LLC.)

Craniofacial morphogenesis is regulated in part by signaling from the Endothelin receptor type A (EDNRA). Pathogenic variants in EDNRA signaling pathway components EDNRA, GNAI3, PCLB4, and EDN1 cause Mandibulofacial Dysostosis with Alopecia (MFDA), Auriculocondylar syndrome (ARCND) 1, 2, and 3, respectively. However, cardiovascular development is normal in MFDA and ARCND individuals, unlike Ednra knockout mice. One explanation may be that partial EDNRA signaling remains in MFDA and ARCND, as mice with reduced, but not absent, EDNRA signaling also lack a cardiovascular phenotype. Here we report an individual with craniofacial and cardiovascular malformations mimicking the Ednra -/- mouse phenotype, including a distinctive micrognathia with microstomia and a hypoplastic aortic arch. Exome sequencing found a novel homozygous missense variant in EDNRA (c.1142A>C; p.Q381P). Bioluminescence resonance energy transfer assays revealed that this amino acid substitution in helix 8 of EDNRA prevents recruitment of G proteins to the receptor, abrogating subsequent receptor activation by its ligand, Endothelin-1. This homozygous variant is thus the first reported loss-of-function EDNRA allele, resulting in a syndrome we have named Oro-Oto-Cardiac Syndrome. Further, our results illustrate that EDNRA signaling is required for both normal human craniofacial and cardiovascular development, and that limited EDNRA signaling is likely retained in ARCND and MFDA individuals. This work illustrates a straightforward approach to identifying the functional consequence of novel genetic variants in signaling molecules associated with malformation syndromes., (© 2020 Wiley Periodicals, Inc.)

Mandibulofacial dysostosis type Guion-Almeida (MFDGA) is a rare disease entity that results in congenital craniofacial anomalies that are caused by abnormal development of the first and second pharyngeal arches. MFDGA is characterized by malar and mandibular hypoplasia, microcephaly, developmental delay, dysplastic ears, and a distinctive facial appearance. Extracraniofacial malformations include esophageal atresia, congenital heart disease, and radial ray abnormalities. Heterozygous mutations in the elongation factor Tu GTP-binding domain containing 2 (EFTUD2) gene have been shown to result in MFDGA. To date, there have been a total of 108 individuals reported in the literature, of whom 95 patients have a confirmed EFTUD2 mutation. The majority of individuals reported in the literature have been of White ethnic origin. Here, we report two individuals of Asian ancestry with MFDGA, each harboring a novel, pathogenic splice site variant in EFTUD2.

We report a case of mandibulofacial dysostosis with microcephaly presenting with seizures. The proband, a 6-year-old Korean boy, had microcephaly, malar and mandibular hypoplasia, and deafness. He showed developmental delay and had suffered recurrent seizures beginning at 21months of age. Electroencephalography revealed occasional spike discharges from the right frontal area. Head magnetic resonance imaging revealed dilatation of the lateral ventricles and a small frontal lobe volume. Whole exome sequencing revealed a de novo frame shift mutation, c.2698_2701 del, of EFTUD2. The epileptic focus was consistent with the reduced frontal lobe volume on head magnetic resonance imaging. Seizures are thus a main feature of mandibulofacial dysostosis with microcephaly, which results from an embryonic development defect due to the EFTUD2 mutation., (Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Acrofacial dysostosis syndrome of Rodriguez is characterized by severe mandibular underdevelopment, upper limb phocomelia with absent fingers, absent fibulae, cleft palate, microtia, and abnormal pulmonary function. First reported in three siblings it was assumed to be an autosomal recessive condition. However, subsequent publication reported a further five simplex occurrences and a living patient with a heterozygous mutation in the SF3B4 gene. Exome sequencing was performed on four fetuses with this disorder, including one of the originally described affected siblings. We identified two heterozygous frameshift mutations in the SF3B4 gene in three of the four fetuses investigated. The observed mutation was apparently de novo in one fetus for whom parental DNA was available. Thus, Acrofacial dysostosis syndrome of Rodriguez is an autosomal dominant condition and the recurrences identified in the initial report were likely due to gonadal mosaicism. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Animal models resembling human mutations are valuable tools to research the features of complex human craniofacial syndromes. This is the first report on a viable dominant mouse model carrying a non-synonymous sequence variation within the endothelin receptor type A gene (Ednra c.386A>T, p.Tyr129Phe) derived by an ENU mutagenesis program. The identical amino acid substitution was reported recently as disease causing in three individuals with the mandibulofacial dysostosis with alopecia (MFDA, OMIM 616367) syndrome. We performed standardized phenotyping of wild-type, heterozygous, and homozygous Ednra Y129F mice within the German Mouse Clinic. Mutant mice mimic the craniofacial phenotypes of jaw dysplasia, micrognathia, dysplastic temporomandibular joints, auricular dysmorphism, and missing of the squamosal zygomatic process as described for MFDA-affected individuals. As observed in MFDA-affected individuals, mutant Ednra Y129F mice exhibit hearing impairment in line with strong abnormalities of the ossicles and further, reduction of some lung volumetric parameters. In general, heterozygous and homozygous mice demonstrated inter-individual diversity of expression of the craniofacial phenotypes as observed in MFDA patients but without showing any cleft palates, eyelid defects, or alopecia. Mutant Ednra Y129F mice represent a valuable viable model for complex human syndromes of the first and second pharyngeal arches and for further studies and analysis of impaired endothelin 1 (EDN1)-endothelin receptor type A (EDNRA) signaling. Above all, Ednra Y129F mice model the recently published human MFDA syndrome and may be helpful for further disease understanding and development of therapeutic interventions., Competing Interests: The authors declare that they have no conflicts of interest.

Background: Miller syndrome (post-axial acrofacial dysostosis) arises from gene mutations for the mitochondrial enzyme dihydroorotate dehydrogenase (DHODH). Nonetheless, despite demonstrated loss of enzyme activity dihydroorotate (DHO) has not been shown to accumulate, but paradoxically urine orotate has been reported to be raised, confusing the metabolic diagnosis., Methods: We analysed plasma and urine from a 4-year-old male Miller syndrome patient. DHODH mutations were determined by PCR and Sanger sequencing. Analysis of DHO and orotic acid (OA) in urine, plasma and blood-spot cards was performed using liquid chromatography-tandem mass spectrometry. In vitro stability of DHO in distilled water and control urine was assessed for up to 60h. The patient received a 3-month trial of oral uridine for behavioural problems., Results: The patient had early liver complications that are atypical of Miller syndrome. DHODH genotyping demonstrated compound-heterozygosity for frameshift and missense mutations. DHO was grossly raised in urine and plasma, and was detectable in dried spots of blood and plasma. OA was raised in urine but undetectable in plasma. DHO did not spontaneously degrade to OA. Uridine therapy did not appear to resolve behavioural problems during treatment, but it lowered plasma DHO., Conclusion: This case with grossly raised plasma DHO represents the first biochemical confirmation of functional DHODH deficiency. DHO was also easily detectable in dried plasma and blood spots. We concluded that DHO oxidation to OA must occur enzymatically during renal secretion. This case resolved the biochemical conundrum in previous reports of Miller syndrome patients, and opened the possibility of rapid biochemical screening., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Acromelic frontonasal dysostosis (AFND) is a distinctive and rare frontonasal malformation that presents in combination with brain and limb abnormalities. A single recurrent heterozygous missense substitution in ZSWIM6, encoding a protein of unknown function, was previously shown to underlie this disorder in four unrelated cases. Here we describe four additional individuals from three families, comprising two sporadic subjects (one of whom had no limb malformation) and a mildly affected female with a severely affected son. In the latter family we demonstrate parental mosaicism through deep sequencing of DNA isolated from a variety of tissues, which each contain different levels of mutation. This has important implications for genetic counselling., (© 2015 The Authors. Clinical Genetics published by John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Ribosome biogenesis is a global process required for growth and proliferation of all cells, yet perturbation of ribosome biogenesis during human development often leads to tissue-specific defects termed ribosomopathies. Transcription of the ribosomal RNAs (rRNAs) by RNA polymerases (Pol) I and III, is considered a rate limiting step of ribosome biogenesis and mutations in the genes coding for RNA Pol I and III subunits, POLR1C and POLR1D cause Treacher Collins syndrome, a rare congenital craniofacial disorder. Our understanding of the functions of individual RNA polymerase subunits, however, remains poor. We discovered that polr1c and polr1d are dynamically expressed during zebrafish embryonic development, particularly in craniofacial tissues. Consistent with this pattern of activity, polr1c and polr1d homozygous mutant zebrafish exhibit cartilage hypoplasia and cranioskeletal anomalies characteristic of humans with Treacher Collins syndrome. Mechanistically, we discovered that polr1c and polr1d loss-of-function results in deficient ribosome biogenesis, Tp53-dependent neuroepithelial cell death and a deficiency of migrating neural crest cells, which are the primary progenitors of the craniofacial skeleton. More importantly, we show that genetic inhibition of tp53 can suppress neuroepithelial cell death and ameliorate the skeletal anomalies in polr1c and polr1d mutants, providing a potential avenue to prevent the pathogenesis of Treacher Collins syndrome. Our work therefore has uncovered tissue-specific roles for polr1c and polr1d in rRNA transcription, ribosome biogenesis, and neural crest and craniofacial development during embryogenesis. Furthermore, we have established polr1c and polr1d mutant zebrafish as models of Treacher Collins syndrome together with a unifying mechanism underlying its pathogenesis and possible prevention.

Mandibulofacial dysostosis (MFD) is a human developmental disorder characterized by defects of the facial bones. It is the second most frequent craniofacial malformation after cleft lip and palate. Nager syndrome combines many features of MFD with a variety of limb defects. Mutations in SF3B4 (splicing factor 3b, subunit 4) gene, which encodes a component of the pre-mRNA spliceosomal complex, were recently identified as a cause of Nager syndrome, accounting for 60% of affected individuals. Nothing is known about the cellular pathogenesis underlying Nager type MFD. Here we describe the first animal model for Nager syndrome, generated by knocking down Sf3b4 function in Xenopus laevis embryos, using morpholino antisense oligonucleotides. Our results indicate that Sf3b4-depleted embryos show reduced expression of the neural crest genes sox10, snail2 and twist at the neural plate border, associated with a broadening of the neural plate. This phenotype can be rescued by injection of wild-type human SF3B4 mRNA but not by mRNAs carrying mutations that cause Nager syndrome. At the tailbud stage, morphant embryos had decreased sox10 and tfap2a expression in the pharyngeal arches, indicative of a reduced number of neural crest cells. Later in development, Sf3b4-depleted tadpoles exhibited hypoplasia of neural crest-derived craniofacial cartilages, phenocopying aspects of the craniofacial skeletal defects seen in Nager syndrome patients. With this animal model we are now poised to gain important insights into the etiology and pathogenesis of Nager type MFD, and to identify the molecular targets of Sf3b4., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Objective: This study aimed to determine external and endonasal deformity, and satisfaction with nasal functioning and appearance, in Treacher Collins syndrome., Study Design: A cross-sectional cohort study was conducted., Methods: Eleven adult patients with Treacher Collins syndrome were compared with 151 controls in terms of satisfaction with nasal functioning and appearance by means of the Nasal Appearance and Function Evaluation Questionnaire. In all patients with Treacher Collins syndrome, external nasal deformities were scored on standardized digital photographs of the nose as rated independently by three experienced physicians. Endonasal deformity was determined by standardized nasal endoscopy., Results: The patients were relatively satisfied with the various esthetic nasal subunits. The most significant functional problems were snoring (P = 0.001) and quality of phonation (P = 0.003). The main external nasal deformities were the dorsal hump (73%), external deviation (≤55%), the bifid or bulbous nasal tip (55%), and columellar septal luxation (55%). In 82% of the patients, a septal deviation was found, often associated with spurs., Conclusion: Satisfaction with esthetics of the nose was fair, but these patients suffer from the functional problems of snoring and impaired quality of phonation. A structured nasal ENT physical examination with nasal endoscopy might determine aspects requiring more attention during treatment. Septorhinoplasty can be performed at an adult age if there is a considerable esthetic wish of the patient and/or nasal obstruction combined with septal deviation. Attention should be paid to dorsal hump reduction, correction of the deviated external osseous framework, septoplasty, and correction of the nasal tip shape., Level of Evidence: 2b., (Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

We report three individuals with a cranioskeletal malformation syndrome that we define as acrofacial dysostosis, Cincinnati type. Each individual has a heterozygous mutation in POLR1A, which encodes a core component of RNA polymerase 1. All three individuals exhibit varying degrees of mandibulofacial dysostosis, and two additionally have limb anomalies. Consistent with this observation, we discovered that polr1a mutant zebrafish exhibited cranioskeletal anomalies mimicking the human phenotype. polr1a loss of function led to perturbed ribosome biogenesis and p53-dependent cell death, resulting in a deficiency of neural-crest-derived skeletal precursor cells and consequently craniofacial anomalies. Our findings expand the genotypic and phenotypic heterogeneity of congenital acrofacial disorders caused by disruption of ribosome biogenesis., (Copyright © 2015 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

The aim of this study was to test the hypothesis that obstructive sleep apnea syndrome (OSAS) exhibits oxidative stress and inflammation in patients who have a congenital, craniofacial anomaly.This prospective, cross-sectional cohort study included ambulant sleep study data to asses OSAS in patients with syndromic craniosynostosis and Treacher Collins syndrome. Laboratory analyses were performed including malondialdehyde, tumor necrosis factor α (TNF-α), interleukin 6, and high-sensitivity C-reactive protein.Forty-eight patients were included; 11 were adults; 37 were children. The patients' body mass indexes were normal, with a median (SD) of 0.7 (-1.82 to 2.48) in children and 20.5 (15.2-29.4) in adults. Obstructive sleep apnea syndrome was diagnosed in 23 of 48 patients. It was mild (median obstructive apnea-hypopnea index [oAHI], 2.3; oxygenation-desaturation index [ODI], 0.9) in 16 patients and moderate/severe in 7 patients (median oAHI, 10.8; ODI, 5.0). Neither oxidative stress nor inflammation had a correlation with the oAHI and ODI. Only TNF-α was found significantly higher in both the OSAS and non-OSAS groups compared with the reference values (median, 15.1 pg/mL and 12.3 pg/mL versus 4.05 [0.0-8.1 pg/mL], P < 0.001 and P < 0.001, respectively).Based on our findings we conclude that (mainly mild) OSAS, oxidative stress, as well as high-sensitivity C-reactive protein and interleukin 6 levels are not abnormal in the day time in a population of nonobese patients with a craniofacial anomaly. The increased level of TNF-α cannot be explained by OSAS. Future research should focus on mapping chronobiologic changes for further interpretation of the results.

Although the relationship between Quality of Life (QoL) and obstructive sleep apnea (OSA) has been reported in several studies, little is known about this relationship among individuals affected with Treacher Collins syndrome (TCS). The aim of this study was to examine the associations between obstructive sleep and QoL in TCS patients. Thirty-six individuals with TCS (8-75 years) were invited to participate in expanded medical examinations, including a sleep study, polysomnography, as well as to respond to questionnaires about health related Health-related quality of life (HRQoL). Twenty-three (64 %) responded to the invitation, but four were later excluded due to additional diagnoses or unconfirmed TCS, and four were below 12 years and excluded due to different scoring rules for sleep and respiratory disturbances in young children and adults. The remaining group comprised 15 adults and adolescents with TCS, 5 male (33 %) and 10 female (66 %). The participants were between 12 and 75 years of age (mean 38.6, SD 18.5). Obstructive sleep was found in 87 % of the patients and several sleep apnea parameters, among these wake time after sleep, subjective snoring and mean saturation, were associated with poorer HRQoL. OSA appears to account for reduced HRQoL in adolescents and adults with TCS.

The human face and skull are an elegant example of the anatomical sophistication that results from the interplay between the molecular cascades and the tissue interactions that are necessary for the proper development of the craniofacial complex. When it fails to develop normally the consequences can have life-long implications for the biological, psychological, and aesthetic wellbeing of an affected person. Among the many syndromes that affect the region, understanding of the biology that underlies Treacher Collins syndrome has advanced in the last decade, particularly concerning the causative TCOF1 gene that encodes TREACLE protein, a serine/alanine-rich nucleolar phosphoprotein with an essential function during ribosome biogenesis in cranial neural crest cells. Abnormal growth and differentiation of these cells affect much of the craniofacial skeleton., (Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.)

Objective: The aim of this study was to describe orofacial features and functions and oral health associated with Treacher Collins syndrome (TCS) in relation to the variable phenotypic expression of the condition., Materials and Methods: The Nordic Orofacial Test-Screening (NOT-S), MHC Questionnaire, MHC Observation chart and clinical examinations of nasal and pharyngeal conditions and chewing and swallowing function were used to assess 19 individuals aged 5-74 years (median 34 years). TCS severity scores were calculated by a clinical geneticist., Results: Orofacial features characterizing the study group were altered profile, increased mandibular angle, narrow hypopharynx and facial asymmetry. Basic orofacial functions such as breathing, eating, facial expression and speech were affected in all subjects demonstrating orofacial dysfunction in at least two NOT-S domains (median NOT-S total score 4/12, range 2-7). Significant correlation was found between the TCS severity scores reflecting phenotypic expression and the NOT-S total scores reflecting orofacial function. Self-reported experience of dry oral mucosa was common. Overall, dental health was good with few carious lesions diagnosed, but considerable need for orthodontic treatment was documented., Conclusions: Altered orofacial features and functions in TCS are common and often persist into late adolescence and adulthood. The functional level was correlated with the phenotypic variability of the condition. The standard of oral health was satisfactory. The findings indicated that individuals with TCS are likely to require lifelong health services related to their oral condition.

Objectives: To review airway management with anesthesia for children with Treacher Collins syndrome (TCS) and determine whether intubation was more difficult with increasing age., Background: Treacher Collins syndrome is a rare disorder of craniofacial development characterized by maxillary, zygomatic, and mandibular dysplasia. TCS is associated with difficult intubation, but reports of airway management are limited to case reports and small cases series. Children with TCS may require multiple general anesthetics, and it has been suggested that intubation becomes more difficult with increasing age., Methods: A retrospective case note review of children with TCS from birth to 18 years undergoing anesthesia from 1971 to 2011 in a single center was performed. Demographic data, procedure type, anesthesia type, method of airway management, modified Cormack-Lehane (MCL) grade of laryngoscopic view, and any other descriptions of airway difficulty or complications were collated., Results: Of 59 patients with TCS, 35 children underwent a total of 240 anesthetics, most commonly for craniofacial surgery. Final airway management consisted of face mask 17%, laryngeal mask airway 16%, endotracheal intubation 49%, and 18% had a preexisting tracheostomy. The laryngeal mask airway provided an adequate airway in all cases when it was used. MCL grade was recorded in 97 cases involving 28 patients: 7% grade 1, 9% grade 2a, 31% grade 2b, 26% grade 3, and 27% grade 4. Fifteen (54%) patients were MCL grade 4 on at least one occasion. Failed intubation occurred in 6 (5%) of 123 cases of planned intubation. The procedure was canceled in two cases (0.8%) because of failure to intubate. Intubation techniques other than conventional direct laryngoscopy were used in 41% of cases. MCL grade increased with increasing age (P = 0.007)., Conclusions: Most children with TCS have difficult laryngoscopic views with many requiring specialized intubation techniques. Direct laryngoscopy becomes more difficult with increasing age. The laryngeal mask airway is a good choice of airway when endotracheal intubation is not required., (© 2012 Blackwell Publishing Ltd.)

Nager syndrome, first described more than 60 years ago, is the archetype of a class of disorders called the acrofacial dysostoses, which are characterized by craniofacial and limb malformations. Despite intensive efforts, no gene for Nager syndrome has yet been identified. In an international collaboration, FORGE Canada and the National Institutes of Health Centers for Mendelian Genomics used exome sequencing as a discovery tool and found that mutations in SF3B4, a component of the U2 pre-mRNA spliceosomal complex, cause Nager syndrome. After Sanger sequencing of SF3B4 in a validation cohort, 20 of 35 (57%) families affected by Nager syndrome had 1 of 18 different mutations, nearly all of which were frameshifts. These results suggest that most cases of Nager syndrome are caused by haploinsufficiency of SF3B4. Our findings add Nager syndrome to a growing list of disorders caused by mutations in genes that encode major components of the spliceosome and also highlight the synergistic potential of international collaboration when exome sequencing is applied in the search for genes responsible for rare Mendelian phenotypes., (Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

Background: Previous reports revealed that difficulties in tracheal intubation for patients with Treacher-Collins syndrome (TCS) progresses as growth; however it declines in those with Pierre-Robin syndrome (PRS). We tried to confirm these reports., Methods: We retrospectively examined the anesthetic records of intubated patients with TCS and PRS without tracheotomy from January 2002 to August 2006., Results: We experienced 10 times of intubation in 5 TCS patients and 6 times in 4 with PRS. No obvious change was observed in its difficulty depending on the growth in both syndromes., Conclusions: The difficulty of intubation depends on the characteristics of each patient rather than growth.

The craniofacial complex is anatomically the most sophisticated part of the body. It houses all the major sensory organ systems and its origins are synonymous with vertebrate evolution. Of fundamental importance to craniofacial development is a specialized population of stem and progenitor cells, known as the neural crest, which generate the majority of the bone, cartilage, connective and peripheral nerve tissue in the head. Approximately one third of all congenital abnormalities exhibit craniofacial malformations and consequently, most craniofacial anomalies are considered to arise through primary defects in neural crest cell development. Recent advances however, have challenged this classical dogma, underscoring the influence of tissues with which the neural crest cells interact as the primary origin of patterning defects in craniofacial morphogenesis. In this review we discuss these neural crest cell interactions with mesoderm, endoderm and ectoderm in the head in the context of a better understanding of craniofacial malformations such as in Treacher Collins and 22q11 deletion syndromes.

The current genetic data stress the importance of musculo-skeletal connections in the development of a coherent system connecting the tendons and aponeurosis muscles with the osseous parts. The observations in tomodensitometry of musculo-skeletal connections in otomandibular dysostosis make it possible qualitatively to observe the development of the muscles and their functions.

Upper airway obstruction and difficult tracheal intubation are often encountered in patients with Treacher Collins syndrome (mandibulofacial dysostosis). In this case report, the use of a laryngeal mask airway (LMATM) in a 10-day-old newborn with severe Treacher Collins syndrome and acute airway obstruction is described. It successfully relieved the airway obstruction and was left in situ for an exceptionally long period of 4 days. The difficult decisions with respect to the management of the airway and specifically the role of the laryngeal mask are described. In our opinion, in some newborns with severe mandibulofacial disorders and upper airway obstruction, where conservative airway management procedures have failed, the laryngeal mask can be considered not only to relieve the obstruction but also to buy time until there is full insight into the medical condition and its consequences.

Purpose: To present a profile of the features and speech in patients with mandibulofacial dysostosis (MFD). Data were collected on occlusion, palatal condition, hearing, resonance, voice, and articulation., Patients: Thirty patients with MFD ranging in age from 1.6 to 21.0 years., Study Design: Retrospective and prospective cross-sectional designs., Setting: Pediatric tertiary care hospital., Results: Sixty percent of the patients had an open bite. Isolated cleft palate was found in 37% with other types of cleft conditions occurring less frequently. Twenty-three percent underwent tracheostomy. All patients demonstrated hearing loss, 93% were conductive and 7% were mixed. Resonance, voice, and articulation were also affected. Seventy-seven percent had aberrant resonance including hypernasality, hyponasality, mixed hyper- and hyponasality or muffled resonance, which was found in 40% of the patients. Voice quality was abnormal in 63%. All patients had articulation errors. Although overlap between categories occurred, results showed that 60% had errors related to malocclusion, 30% demonstrated errors usually associated with velopharyngeal inadequacy and 50% had general articulatory or phonological errors that could be attributed to other causes., Conclusions: The features and speech of patients with MFD are complex. The speech disorders may have multiple overlapping etiologies that require careful differential diagnosis. This is imperative to establish appropriate treatment regimens and evaluate clinical outcomes.

Children with craniofacial anomalies often have compromise of the upper airway, a condition with potential for morbidity and mortality. In children with microretrognathia, the diminutive size and retruded position of the mandible reduces the size of the oropharynx, thereby predisposing to glossoptosis and airway obstruction. Although several authors have reported successful use of mandibular distraction osteogenesis to alleviate this type of upper airway obstruction, the physiologic relationship between changes in mandibular shape, size, and position and upper airway dynamics remains undefined. The purpose of this study was to develop methodologies to quantitatively evaluate upper airway dynamics in children with micrognathia both before and after mandibular distraction osteogenesis. The patient population consisted of four children with micrognathia who had successfully undergone upper airway stabilization by bilateral mandibular distraction osteogenesis. The data used were digitally archived computed tomographic scan data from high-resolution, thin-slice head computed tomographic scans obtained before and after mandibular distraction. Upper airway evaluation was performed in two ways: static and dynamic. Static analysis consisted of computer quantification of predistraction and postdistraction mandibular and upper airway volumes using Analyze imaging software. Dynamic analysis consisted of fabrication of rigid stereolithographic hollow cast models of the upper airway produced from computed tomographic scan data. Models were used for characterization of upper airway resistance and flow patterns as related to respiration. After distraction osteogenesis, mandibular total volume increased 32, 32, 18, and 25 percent (mean, 27 percent) and upper airway volume increased by 20, 31, 23, and 71 percent (mean, 37 percent). A significant decrease in flow resistance, both inspiratory and expiratory, was observed in the patient with the greatest upper airway volume increase (71 percent) after distraction. After distraction, the inspiratory resistance was diminished by 51 percent and the expiratory resistance diminished by 85 percent. However, the three patients with more modest upper airway volume increases of 20 to 31 percent demonstrated no statistically significant change in flow resistance after distraction. Results of this study support the conclusion that distraction osteogenesis of the micrognathic mandible increases the volume of the upper airway, roughly paralleling the increase in mandibular volume. In the biomechanical airway model studied, upper airway volume expansion has been shown to be able to decrease the flow resistance over the length of the airway, presumably secondary to an increase in the average cross-sectional area. The artificial rigidity of the stereolithographic "airway" compared with the elasticity of the human upper airway may account for the insensitivity of this model to smaller but clinically significant airway changes.

Treacher Collins syndrome is seen once in 10.000 births. Inheritance is autosomal dominant with variable expressivity. The most prominent symptoms are antimongoloid slant of the eyelids, hypo- or even aplasia of the zygomata, very hypoplastic mandible with receding chin, deformed ear lobes and conductive hearing loss. With two to three operations a considerable improvement can be achieved. The correction of the eyelids is often the most difficult problem.

Objective: To monitor and compare facial morphology and growth in three individuals with variable expression of mandibulofacial dysostosis (MFD) in terms of changes in the skeletal profile and in terms of growth in the circummaxillary sutures and temporomandibular joints (TMJs)., Design: Retrospective conventional profile roentgenography (mean age 9 to 18 years) and prospective roentgen stereometric analysis (RSA) (mean age 7 to 17 years)., Setting: Center for Craniofacial Anomalies and Department of Plastic and Reconstructive Surgery, Malmö University Hospital, Sweden., Patients: The first three MFD patients seen by one of the authors (B.R.)., Interventions: Surgery was performed at the Department of Plastic and Reconstructive Surgery. Implants were inserted at surgery under general anesthesia. Roentgen examinations were performed in connection with continued clinical evaluations and treatment., Main Outcome Measures: All profile roentgenograms were traced and measured by one of the authors (K.-V.S.) using a conventional point-based analysis., Results: The more afflicted patient showed a greater total difference in profile morphology and growth from the norm and more pronounced effects of articular growth restriction. Little change in the skeletal profile was associated with considerable displacement of the jaws., Conclusions: The variability in MFD expression and surgical procedures in our patients is reflected less in the skeletal profile morphology and growth and more in the displacement of the jaws.

This review article describes normal and abnormal development of the mandible. The focus is on the characteristics of the mandible and its attached muscles in the various types of hemifacial microsomia and in Nager syndrome. Management protocols for these two types of malformations are presented in relation to development stages.

Also known as Treacher-Collins or Franceschetti-Zwahlen-Klein syndrome, the mandibulofacial dysostosis is characterized by bilateral involvement of facial structures, including malar and mandibular hypoplasia, underdeveloped zygomatic bone, antimongoloid slant and external and middle ear anomalies. The syndrome is inherited as an autosomal dominant trait with incomplete penetrance and variable expressivity. The authors report the case of a 19-years-old patient with characteristic cranio-facial malformations.

Nager acrofacial dysostosis (NAFD) combines the facial anomalies of mandibulofacial dysostosis (Treacher-Collins-Francescetti) with hypoplastic/aplastic or triphangeal thumbs. The MURCS association consists of Müllerian duct aplasia, renal aplasia, cervicothoracic somite dysostosis with Klippel-Feil anomaly, and often defects of the facio-auriculo-vertebral (Goldenhar) spectrum. We describe a child with NAFD, MURCS anomaly (Klippel-Feil anomaly, vertebral synostoses, left renal agenesis), and left pulmonary agenesis. Our proband appears to express a unique anomaly of blastogenesis, simultaneously affecting the acrorenal, the mandibulofacial, and the cervicothoracic developmental fields, combining clinical manifestations of the MURCS, NAFD, VACTERL, and pulmonary agenesis associations. All anomalies may be traced back to abnormal blastogenesis, occurring during the third or the fourth week of embryonic development, and show that NAFD is a polytopic developmental field defect.

A total of 371 serial dental panoramic radiographs from 71 children with juvenile chronic arthritis (JCA) were examined to determine the presence and extent of radiographically detectable condylar abnormalities. The series included 12 children with so called 'bird face' deformity and 55 in whom facial growth was judged to be normal. By the age of 15 years, 27 patients (38 per cent), showed lesions of the TMJ, of which 14 (55 per cent) were bilateral. Of those cases with unilateral destruction, the left condyle was affected nine times more frequently than the right. All of the children with 'bird face' deformity had condylar abnormality, but these facial characteristics should not be considered pathognomonic of juvenile chronic arthritis. Moderate to severe condylar abnormality was detectable in 10.9 per cent of children with normal facial growth, and where condylar destruction is present it can often be established as early as 8 years. Systemic corticosteroids appear to have little or no effect on the condyle or mandibular growth.

Treacher Collins syndrome is an autosomal dominant disorder of craniofacial development, the features of which include conductive hearing loss and cleft palate. In the absence of a candidate gene, a positional cloning approach has been used to isolate the mutated gene which maps to chromosome 5q31.3-32. Flanking markers were identified and a yeast artificial chromosome and cosmid contig of the region defined by these markers was created as a prelude to the creation of a transcript map of the region. Analysis of genes isolated using this approach resulted in the identification of the mutated gene. While the function of the gene remains unknown, the identification of 20 mutations spread throughout the gene, all of which would result in the insertion of a premature termination codon into the reading frame, suggests that the mechanism underlying the disease is haploinsufficiency.

The authors have examined through the electromygraphic-kinesiographic system provided, the mandibolar movements and the electric activity of the masseter and temporal muscles of group of 25 subjects, aged 22-25 (15 women and 10 men), with complete natural dentition, whose history and clinical examination of cranio-mandibular disorders were negative. The aim of the study is to analyse the values come out by these instrumental researches and to compare them with the already existing literature, trying to obtain standard data of "normality", to be used as comparative and diagnostic parameters for this age range and, on the other hand, as a further method of evaluation for electromyiografic-kinesiographic and electromyiographic analysis of subjects suffering from algic-dysfunctional pathology of the cranio-mandibular apparatus. The analysed champion of healthy subjects, with symmetrical electromyiographic normal values (temporan muscles 0.5-2.5 microvolts, masseter muscles 0.5-2.0 microvolts), presents physiological mandibular movementes along the three space axes: furthermore the results outlined by the existing literature, according to which the female champion has a lower muscular electric potential and mandibular dinamic paths than the male champion, are confirmed. The authors point out the importance of computerised clinical research, not only to get data, but also to store them and to be able to compare them in long term.

Treatment of patients with craniofacial (CF) anomalies necessitates knowledge about normal CF growth and how it deviates in the abnormal state. There are different basic types of CF anomalies and various kinds of aberrations that influence CF development. These factors might help to explain why patients display growth variations. The effect of surgery on subsequent development is significant, but the heterogeneity among patients with regards to the morphology, etiology, and pathogenesis of the anomalies could also explain certain growth results. Roentgencephalometric findings related to CF growth in three different groups of anomalies are discussed.

Treacher Collins syndrome (TCOF1) is an autosomal dominant disorder of craniofacial development in which there is considerable variability in the clinical manifestations. The TCOF1 locus has previously been mapped to chromosome 5q32-33.2 and markers flanking the disease locus identified. In the current investigation we have analysed eight short tandem repeat polymorphisms for linkage to TCOF1 in a large family with multiple affected individuals. Linkage analysis suggested that TCOF1 in this family was linked to markers in the region 5q32-33.2. We have used the results to make diagnostic predictions in certain mildly affected and apparently unaffected individuals.

The ocular findings and visual prognosis were reviewed in 24 patients with the Treacher-Collins syndrome who were evaluated in the craniofacial clinic in the Division of Pediatric Ophthalmology at Children's Hospital of Philadelphia between 1980 and 1991. All patients had some abnormality. Vision loss was present in 37% of patients. Amblyopia was present in 33%, significant refractive errors were present in 58%, and anisometropia was documented in 17%. Strabismus was present in 37% and significant lid and adnexal abnormalities were seen in 96%. The prognosis for normal vision in at least one eye is good but vision loss secondary to amblyopia is more resistant to treatment owing to other medical problems and social concerns.

Using longitudinal roentgencephalometry, we studied craniofacial growth in two children with mandibulofacial dysostosis. In one child, data were supplemented by three-dimensional reconstructions of CT scans and stereolithographic models of the craniofacial skeleton. Progressive basilar kyphosis was found in both children, the hypothesized caused being bending of the cranial base at the level of the sphenofrontal suture. Such bending acting in concert with abnormal growth of the mandible led to impairment of the airway. We advocate careful monitoring of craniofacial growth and respiratory function in mandibulofacial dysostosis from birth through adolescence.

Although the hearing loss of patients with Treacher Collins syndrome is well documented, few studies have reported jointly on their hearing loss and ear pathology. This paper reports on the hearing loss and computerized tomography (CT) assessments of ear malformations in a large pediatric series of patients with Treacher Collins. Of the 29 subjects assessed by the Craniofacial Program between 1986 and 1990, paired audiologic and complete CT assessments were available for 23 subjects. The external ear canal abnormalities were largely symmetric, either bilaterally stenotic or atretic. In most cases, the middle ear cavity was bilaterally hypoplastic and dysmorphic, and ossicles were symmetrically dysmorphic or missing. Inner ear structures were normal in all patients. The majority of patients had a unilateral or bilateral moderate or greater degree of hearing loss and almost half had an asymmetric hearing loss. The hearing loss of all subjects was conductive, except for three whose loss was bilateral mixed. Two types of bilaterally symmetric hearing loss configurations, flat and reverse sloping, were noted. Conductive hearing loss in patients with Treacher Collins is mainly attributable to their middle ear malformations, which are similar for those of patients with malformed or missing ossicles.

Mandibuloacral dysplasia (MAD) is a syndrome characterized by partial lipodystrophy and a distinct phenotype, which includes progressive osteolysis of the mandible and clavicles, cutaneous atrophy, joint contractures, and diabetes mellitus. We now describe the results of hyperinsulinemic glucose clamps performed in conjunction with indirect calorimetry in two subjects with MAD. At a glucose level of 5 mmol/L and insulin concentration of over 6.5 x 10(4) pmol/L, glucose disposal rates were less than 20% of maximum insulin-stimulated glucose disposal in five nondiabetic controls. Basal hepatic glucose output was elevated in the two patients and was incompletely suppressed by a 1200 mU/m2.min infusion of insulin. Glucose and lipid oxidation rates were inappropriately elevated, reflecting marked hypermetabolism. Pharmacological concentrations of insulin failed to normally suppress lipid oxidation, diminish FFA levels, or adequately suppress glucagon levels. In summary, MAD is a unique form of lipodystrophic diabetes characterized by typical somatic features, extreme insulin resistance, and marked hypermetabolism.

We examined 14 patients from nine families referred with the diagnosis of Treacher Collins syndrome. We noted seven significant ocular findings including the following: a subnormal horizontal palpebral fissure length and inferomedial displacement of the lateral canthus in primary gaze; further medial displacement (4.0 mm or more) of the lateral canthus with resultant shortening of the horizontal fissure length on forced eyelid closure (fissure narrowing sign); partial-thickness eyelid colobomata localized to the nasal one half to two thirds of the lower eyelids; bilateral absence of the inferior lacrimal puncta; bilateral blepharoptosis; inferior displacement of the palpebral fissures; and regular astigmatism without any consistent orientation of the axis of astigmatism relative to the lower eyelid defects, blepharoptosis, or lateral canthus. The fissure narrowing sign correlates with known anatomic deficiencies in the Treacher Collins syndrome and may prove valuable in confirming the diagnosis in patients who lack certain typical features.

Seven patients who had the complete form of mandibulofacial dysostosis were examined to determine the prevalence of nasolacrimal abnormalities. Bilateral inferior punctal atresia (and, by implication, accompanying inferior canalicular atresia) was identified in all seven patients; a 95% confidence interval for the true underlying rate of this finding in mandibulofacial dysostosis is 59% to 100%. Lacrimal surgery was required in only one patient who had coexistent bilateral nasolacrimal duct obstruction and chronic dacryocystitis and who responded well to bilateral dacryocystorhinostomy.