Missense variants in ANKRD11 cause KBG syndrome by impairment of stability or transcriptional activity of the encoded protein.

PURPOSE: Although haploinsufficiency of ANKRD11 is among the most common genetic causes of neurodevelopmental disorders, the role of rare ANKRD11 missense variation remains unclear. We characterized clinical, molecular, and functional spectra of ANKRD11 missense variants. METHODS: We collected clinical information of individuals with ANKRD11 missense variants and evaluated phenotypic fit to KBG syndrome. We assessed pathogenicity of variants through in silico analyses and cell-based experiments. RESULTS: We identified 20 unique, mostly de novo, ANKRD11 missense variants in 29 individuals, presenting with syndromic neurodevelopmental disorders similar to KBG syndrome caused by ANKRD11 protein truncating variants or 16q24.3 microdeletions. Missense variants significantly clustered in repression domain 2 at the ANKRD11 C-terminus. Of the 10 functionally studied missense variants, 6 reduced ANKRD11 stability. One variant caused decreased proteasome degradation and loss of ANKRD11 transcriptional activity. CONCLUSION: Our study indicates that pathogenic heterozygous ANKRD11 missense variants cause the clinically recognizable KBG syndrome. Disrupted transrepression capacity and reduced protein stability each independently lead to ANKRD11 loss-of-function, consistent with haploinsufficiency. This highlights the diagnostic relevance of ANKRD11 missense variants, but also poses diagnostic challenges because the KBG-associated phenotype may be mild and inherited pathogenic ANKRD11 (missense) variants are increasingly observed, warranting stringent variant classification and careful phenotyping.

Evaluation of dental maturity in Muenke syndrome, Saethre-Chotzen syndrome, and TCF12-related craniosynostosis.

OBJECTIVES: To determine whether dental maturity (dental development) was delayed in patients with Muenke syndrome, Saethre-Chotzen syndrome, and TCF12-related craniosynostosis, compared with a Dutch control group without syndromes. MATERIALS AND METHODS: This study included 60 patients (38 patients with Muenke syndrome, 17 patients with Saethre-Chotzen syndrome, and 5 with TCF12-related craniosynostosis), aged 5.8-16.8 years that were treated at the Department of Oral Maxillofacial Surgery, Special Dental Care, and Orthodontics, in Sophia Children's Hospital, Erasmus University Medical Center, Rotterdam, the Netherlands. Dental age was calculated according to Demirjian's index of dental maturity. The control group included 451 children without a syndrome. RESULTS: Compared with the control group, dental development was delayed by an average of one year in 5- to 8-year-old patients with Muenke syndrome (P = 0.007) and in 8- to 10-year-old patients with Saethre-Chotzen syndrome (P = 0.044), but not in patients with TCF12-related craniosynostosis. CONCLUSIONS: Our results indicated that dental development was delayed by one year, on average, in patients with Muenke syndrome and Saethre-Chotzen syndrome, compared with a Dutch control group without syndromes. IMPLICATIONS: Our findings have improved the understanding of dental development in patients with Muenke and Saethre-Chotzen syndrome. These results can provide guidance on whether the orthodontist needs to consider growth disturbances related to dental development.

Inactivation of IL11 signaling causes craniosynostosis, delayed tooth eruption, and supernumerary teeth.

Craniosynostosis and supernumerary teeth most often occur as isolated developmental anomalies, but they are also separately manifested in several malformation syndromes. Here, we describe a human syndrome featuring craniosynostosis, maxillary hypoplasia, delayed tooth eruption, and supernumerary teeth. We performed homozygosity mapping in three unrelated consanguineous Pakistani families and localized the syndrome to a region in chromosome 9. Mutational analysis of candidate genes in the region revealed that all affected children harbored homozygous missense mutations (c.662C>G [p.Pro221Arg], c.734C>G [p.Ser245Cys], or c.886C>T [p.Arg296Trp]) in IL11RA (encoding interleukin 11 receptor, alpha) on chromosome 9p13.3. In addition, a homozygous nonsense mutation, c.475C>T (p.Gln159X), and a homozygous duplication, c.916_924dup (p.Thr306_Ser308dup), were observed in two north European families. In cell-transfection experiments, the p.Arg296Trp mutation rendered the receptor unable to mediate the IL11 signal, indicating that the mutation causes loss of IL11RA function. We also observed disturbed cranial growth and suture activity in the Il11ra null mutant mice, in which reduced size and remodeling of limb bones has been previously described. We conclude that IL11 signaling is essential for the normal development of craniofacial bones and teeth and that its function is to restrict suture fusion and tooth number. The results open up the possibility of modulation of IL11 signaling for the treatment of craniosynostosis.

Most Efficient and Meaningful Patient-Reported Appearance Assessment in Different Cleft Types and Age Groups with CLEFT-Q.

BACKGROUND: The CLEFT-Q, a questionnaire developed and validated specifically for cleft patients, contains seven appearance scales. The International Consortium of Health Outcomes Measurement (ICHOM) has incorporated only some CLEFT-Q appearance scales in the Standard Set to minimize burden. This study evaluates which appearance scales provide the most meaningful information in the different cleft types at specific ages, for the most efficient cleft appearance outcome assessment. METHODS: Within this international multicenter study, outcomes of the seven appearance scales were collected, either as part of the ICHOM Standard Set, or as part of the field test study performed to validate the CLEFT-Q. Analyses were performed in separate age groups and cleft types, and involved univariate regression analyses, trend analyses, t tests, correlations, and floor and ceiling effects. RESULTS: A total of 3116 patients were included. Scores for most appearance scales showed a downward trend by age group, with the exception of the Teeth and Jaw scales. In all cleft types, several scales correlated strongly with each other. No floor effects were observed, but ceiling effects were found in several scales in different age groups, most often in the CLEFT-Q Jaw scale. CONCLUSIONS: A proposition for the most meaningful and efficient appearance outcome assessment in cleft patients is made. It was composed so that recommendations are of value for different cleft protocols and initiatives. Suggestions for the use of scales in the ICHOM Standard Set at different ages are given, and also from a clinical perspective. Use of the CLEFT-Q Scar, Lips, and Nose scales will provide additional relevant information.

Mandibular distraction to correct severe non-isolated mandibular hypoplasia: The role of drug-induced sleep endoscopy (DISE) in decision making.

OBJECTIVES: In patients with mandibular hypoplasia, mandibular distraction osteogenesis (MDO) aims to relieve tongue-based airway obstruction. Drug-induced sleep endoscopy (DISE) provides a dynamic assessment of the upper airway and visualizes anatomical site and cause of airway obstruction. The aim of this study was to evaluate the effect of MDO on tongue-based airway obstruction found by DISE within a non-isolated patient population with severe upper airway obstruction (UAO). Furthermore, we aimed to assess the additional value of DISE in clinical decision making by correlating DISE findings to functional airway outcomes after MDO. METHODS: Findings on DISE in children who underwent MDO were retrospectively gathered and evaluated. According to DISE findings, severity of tongue-based obstruction was scored using a 4-step classification similar to the one that is used by Bravo et al.. Intubation conditions were scored according to the Cormack Lehane score (CLS). Pre-and postoperative DISE findings were compared and correlated with functional airway outcomes following MDO. RESULTS: In 19 out of 28 MDO procedures, both a pre-and postoperative DISE was available. Tongue-based obstruction scores improved in 13 procedures, which correlated to a functional improvement in seven. Postoperative tongue-based obstruction differed significantly between patients with successful MDO and patients treated unsuccessfully (2.00 ((Interquartile range (IQR) 1.00-2.00) vs. 3.00 (IQR 2.00-4.00), p = 0.028), whereas this difference was not significant for the CLS (1.00 (IQR 1.00-1.50) vs. 2.00 (IQR 1.00-4.00), p = 0.066). If no improvement of tongue-based obstruction was seen, MDO is very unlikely to be successful on the functional airway. CONCLUSIONS: DISE provides information on the site and nature of airway obstruction and can visualize the effect of MDO on the severity of tongue-based airway obstruction. Therefore, it can be of additional value in understanding the differences in functional airway outcomes after MDO and aids in deciding appropriate and targeted treatment. Hence, standardized use of DISE, in addition to the clinical assessment of mandibular position and a polysomnography, during MDO management is highly recommended.

Evaluation of the OSA treatment protocol in syndromic craniosynostosis during the first 6 years of life.

INTRODUCTION: Obstructive sleep apnea (OSA) is frequently present in patients with syndromic craniosynostosis. The aim of this study is to determine the long-term effectiveness of our OSA treatment protocol in our tertiary center in a cohort of children with syndromic craniosynostosis. METHODS: Children with syndromic craniosynostosis born between January 2005 and December 2013 were eligible for inclusion (n = 114). Data from ambulatory and inhospital polysomnographies were used. The obstructive-apnea/hypopnea index was used for OSA classification. RESULTS: Polysomnographies were performed in 83 patients. Mild OSA was diagnosed in 19, moderate in six, and severe in seven children. Of the 32 patients with OSA, 12 patients (37.5%) initially received expectant care of which OSA resolved spontaneously in nine without recurrence. Twenty patients were surgically treated. Adenotonsillectomy (ATE) had a 90% success rate with no OSA recurrence. Monobloc surgery was performed in four patients with mild OSA, although not OSA-indicated. Monobloc was performed for moderate or severe OSA in six patients, in four patients in combination with ATE and with mandibular distraction in one. Monobloc surgery for moderate or severe OSA had a 100% success rate in treating OSA and decannulation. CONCLUSION: Expectant care is often sufficient to resolve mild OSA in patients with syndromic craniosynostosis, and should also be considered in patients with moderate OSA with close follow-up. ATE has an important role in the OSA treatment protocol. Monobloc surgery, combined with mandibular distraction on indication, is effective in resolving moderate to severe OSA with a stable long-term result.

Non-surgical and surgical interventions for airway obstruction in children with Robin Sequence.

There is widespread lack of consensus regarding treatment of airway obstruction in children with Robin Sequence. This study aimed to systematically summarize outcomes of non-surgical and surgical options to treat airway obstruction in children with Robin Sequence. The authors searched the Medline, EMBASE and CENTRAL databases. Studies primarily on mandibular distraction were excluded. Study quality was appraised with the Methodological Index for Non-Randomized Studies (MINORS) score. Forty-eight studies were included, of which 45 studies had a retrospective non-comparative set up, two studies had a prospective design and one study was a clinical trial. The mean MINORS score was 7.3 (range 3-10). The rates of successful relief of the airway obstruction (SRoAO) were: not available for orthodontic appliance (2 studies, n = 24), 67-100% for nasopharyngeal airway (6 studies, n = 126); 100 % for non-invasive respiratory support (2 studies, n = 12); 70-96% for tongue-lip adhesion (11 studies, n = 277); 50-84% for subperiosteal release of the floor of the mouth (2 studies, n = 47); 100% for mandibular traction (3 studies, n = 133); 100% for tracheostomy (1 study, n = 25). The complication rate ranged from zero to 55%. Although SRoAO rates seemed comparable, high-level evidence remains scarce. Future research should include description of the definition, treatment indication, and objective outcomes.

Robin sequence: A European survey on current practice patterns.

To provide an overview of current practice patterns with regard to Robin sequence (RS) patients in Europe, a survey was conducted among European clinicians. This online survey consisted of different sections assessing characteristics of the respondent and clinic, definition, diagnosis, treatment, and follow-up. In total, surveys from 101 different European clinics were included in the analysis, and 56 different RS definitions were returned. The majority (72%) of the respondents used a sleep study system to determine the severity of the airway obstruction. A total of 63% used flexible endoscopy and 16% used rigid endoscopy in the diagnostic process. Treatment of the airway obstruction differed considerably between the different countries. Prone positioning for mild airway obstruction was the treatment modality used most often (63%). When prone positioning was not successful, a nasopharyngeal airway was used (62%). Surgical therapies varied considerably among countries. For severe obstruction, mandibular distraction was performed most frequently. Three-quarters of the respondents noted the presence of catch-up growth in their patient population. This first European survey study on definition and management of RS shows that there are considerable differences within Europe. Therefore, we would encourage the establishment of national (and international) guidelines to optimize RS patient care.

Unravelling Robin sequence: considerations of diagnosis and treatment.

OBJECTIVES/HYPOTHESIS: The airway management of children with Robin sequence is controversial. This study provides an overview of a single-center experience with the diagnosis and treatment of 59 children with Robin sequence. STUDY DESIGN: Retrospective cohort study. METHODS: We conducted a retrospective cohort study of 59 children (<1 year old) with Robin sequence managed between 2000 and 2010. Robin sequence was defined as the presence of mandibular hypoplasia and clinical signs of airway obstruction. Data were collected on demographic characteristics, the presence of a syndrome, the perinatal period, and the management of airway and nutritional problems. RESULTS: Eighteen children (31%) needed respiratory support because of severe respiratory distress, and a sleep study found obstructive apneas in another eight children who had been managed by prone positioning and/or monitoring. In the isolated group significantly fewer children needed respiratory support compared to the nonisolated group. After the age of 1 year, 10% of the Robin sequence cohort was still in need of treatment for obstructive symptoms. Almost half (47%) needed temporary nutritional support. CONCLUSIONS: The prevalence of respiratory distress in children with Robin sequence is high. In most children, treatment with prone positioning was sufficient to relieve the airway obstruction. Successful treatment with prone positioning was significantly more often seen in children with an isolated Robin sequence. About one-third of all Robin sequence children needed respiratory support in the neonatal and/or infant period. However, in childhood, only 10% of the total Robin sequence cohort was still dependent on respiratory support.

Orbital aspects following monobloc advancement in syndromic craniosynostosis.

The monobloc advancement with distraction is a treatment modality for syndromic craniosynostosis, to correct exorbitism, upper airway compromise and malocclusion. In this report orbital volume and movements of (peri-)orbital structures and globes of seven patients following monobloc distraction are evaluated. In preoperative and postoperative CT-scans orbital volume was assessed and a 3D coordinate system with eleven landmarks was used to measure the movements of orbital structures and globes and to measure the change of exorbitism. Correlation between orbital volume, movements of the orbital structures and change in exorbitism was studied. The orbital volume increased by 49.9% (left) and 50.4% (right). The average anterior movement of the bone was 13.6 mm (left) and 13.9 mm (right). The mean anterior movement of the left globe was 5.8 mm and of the right globe 5.3 mm. The ratio of globe/bone movement was 0.4. Exorbitism decreased with 7.8 mm (left) and 8.1 mm (right). Differences between left and right for orbital volume, for movements and for the decrease in exorbitism were not significant. Volume enlargement and decrease in exorbitism were correlated (p ≤ 0.05). Following monobloc advancement orbital volume increases, (peri-)orbital structures and the globe move forward and exorbitism diminishes.

Upper airway changes in syndromic craniosynostosis patients following midface or monobloc advancement: correlation between volume changes and respiratory outcome.

In syndromic craniosynostosis patients, respiratory insufficiency may be a pressing indication to surgically increase the patency of the upper airway by midface or monobloc advancement. In this study the volume changes of the upper airway and the respiratory outcome following midface (Le Fort I or III) or monobloc advancement in ten syndromic craniosynostosis patients are evaluated. Pre- and postoperatively, the airway volume was measured using a semi-automatic region growing method. Respiratory data were correlated to the volume measurements. In nine patients the outcome of upper airway volume measurements correlated well to the respiratory outcome. Three of these patients showed a minimal airway volume gain or even volume loss, and no respiratory improvement was found. In one monobloc patient improvement of the respiratory outcome without an evident volume gain of the upper airway was found. The majority of patients with Le Fort III advancement showed respiratory improvement, which for the greater part correlated to the results of the volume analysis. In monobloc patients the respiratory outcomes and volume measurements were less obvious. Preoperative endoscopy of the upper airway is advocated to identify the level of obstruction in patients with residual obstructive sleep apnoea.

Long-term results after 40 years experience with treatment of rare facial clefts: Part 1--Oblique and paramedian clefts.

BACKGROUND: Oblique and paramedian rare facial clefts impose a major reconstructive challenge and long-term assessments of the outcomes remain scarce. This study provides new details regarding surgical techniques and timing, influence of growth, and difficulties of this pathology on the long-term; a guideline for surgical treatment is given. METHODS: Twenty-nine adults with an oblique or paramedian facial cleft and surgically treated in the authors' unit between 1969 and 2009, were included. The long-term evaluation was based on series of photographs, 3D-CT's, X-rays, operation data, and was specified per facial area. RESULTS: The mean number of performed operations per patient was 10.6 (range: 1-26). Vertical dystopia is not caused by previous surgery, but by growth deficiencies of the maxilla. In all patients with vertical dystopia, its presence and severity were clear at the age of five, and it should ideally be treated shortly after that age. In mild cases grafting seems sufficient, but in more severe cases orbital translocation is necessary. Costochondral grafts showed the best long-term results in both orbital and nasal reconstructions. Major nose reconstruction is best delayed until adolescence. For an optimal final result in selected cases, correction of midface hypoplasia at adolescence is necessary. CONCLUSION: The three-dimensional underdevelopment of the midface region plays a central role in the deformities of most patients, but is complex and difficult to correct. The provided guideline should help to minimize the number of operations and ameliorate long-term results.

Three-dimensional airway changes after Le Fort III advancement in syndromic craniosynostosis patients.

BACKGROUND: To investigate the changes of upper airway volume in syndromic craniosynostosis patients following Le Fort III advancement, computed tomographic scans were analyzed and related to the amount of advancement. METHODS: In this retrospective study, the preoperative and postoperative computed tomographic scans of 19 patients with syndromic craniosynostosis who underwent Le Fort III advancement were analyzed. In four cases, preoperative polysomnography demonstrated obstructive sleep apnea. The airway was segmented using a semiautomatic region growing method with a fixed Hounsfield threshold value. Airway volumes of hypopharynx and oropharynx (compartment A) and nasopharynx and nasal cavity (compartment B) were analyzed separately, as was the total airway volume. Advancement of the midface was recorded using lateral skull radiographs. Data were analyzed for all patients together and for patients with Crouzon/Pfeiffer and Apert syndromes separately. RESULTS: Airway volume increased significantly in compartment A (20 percent; p = 0.044) and compartment B (48 percent; p < 0.001), as did total airway volume in (37 percent; p < 0.001) in the total study group. No significant differences in volume changes were found comparing Apert with Crouzon/Pfeiffer patients. No distinct relation could be found between advancement of the midface and volume gain either in the total study group or in Apert and Crouzon/Pfeiffer patient groups separately. Postoperative polysomnography showed significant improvement of obstructive sleep apnea in all four patients. CONCLUSIONS: A significant improvement of the upper airway after Le Fort III advancement in syndromic craniosynostosis patients is demonstrated. No distinct relation could be observed between advancement and airway volume changes.

Internal carotid dissection after Le Fort III distraction in Apert syndrome: a case report.

A 10-year-old girl with Apert syndrome underwent a Le Fort III osteotomy with the positioning of internal and external distraction devices. The operation was straightforward with no intraoperative complications. Very soon after completion of surgery an anisocoria (unilateral dilation of a pupil) was noticed. This was followed by intracranial oedema which was fatal. The aetiology was dissection of the right internal carotid artery is reported. The complications of Le Fort osteotomies are discussed regarding patients with complex syndromal craniosynostosis and midface hypoplasia, such as Apert syndrome.