Cases Of Syndromic Craniosynostosis Research Articles

AXIN1 mutations in nonsyndromic craniosynostosis.

Occurring once in every 2000 live births, craniosynostosis (CS) is the most frequent cranial birth defect. Although the genetic etiologies of syndromic CS cases are well defined, the genetic cause of most nonsyndromic cases remains unknown. The authors analyzed exome or RNA sequencing data from 876 children with nonsyndromic CS, including 291 case-parent trios and 585 additional probands. The authors also utilized the GeneMatcher platform and the Gabriella Miller Kids First genome sequencing project to identify additional CS patients with AXIN1 mutations. The authors describe 11 patients with nonsyndromic CS harboring rare, damaging mutations in AXIN1, an inhibitor of Wnt signaling. AXIN1 regulates signaling upstream of key mediators of osteoblast differentiation. Three of the 6 mutations identified in trios occurred de novo in the proband, while 3 were transmitted from unaffected parents. Patients with nonsyndromic CS were highly enriched for mutations in AXIN1 compared to both expectation (p = 0.0008) and exome sequencing data from > 76,000 healthy controls (p = 2.3 × 10-6), surpassing the thresholds for genome-wide significance. These findings describe the first phenotype associated with mutations in AXIN1, with mutations identified in approximately 1% of nonsyndromic CS cases. The results strengthen the existing link between Wnt signaling and maintenance of cranial suture patency and have implications for genetic testing in families with CS.

Whole-exome sequencing in syndromic craniosynostosis increases diagnostic yield and identifies candidate genes in osteogenic signaling pathways.

Craniosynostosis (CS) is a common congenital anomaly defined by premature fusion of one or more cranial sutures. Syndromic CS involves additional organ anomalies or neurocognitive deficits and accounts for 25%-30% of the cases. In a recent population-based study by our group, 84% of the syndromic CS cases had a genetically verified diagnosis after targeted analyses. A number of different genetic causes were detected, confirming that syndromic CS is highly heterogeneous. In this study, we performed whole-exome sequencing of 10 children and parents from the same cohort where previous genetic results were negative. We detected pathogenic, or likely pathogenic, variants in four additional genes (NFIA, EXTL3, POLR2A, and FOXP2) associated with rare conditions. In two of these (POLR2A and FOXP2), CS has not previously been reported. We further detected a rare predicted damaging variant in SH3BP4, which has not previously been related to human disease. All findings were clustered in genes involved in the pathways of osteogenesis and suture patency. We conclude that whole-exome sequencing expands the list of genes associated with syndromic CS, and provides new candidate genes in osteogenic signaling pathways.

Benefits of clinical criteria and high-throughput sequencing for diagnosing children with syndromic craniosynostosis

An accurate diagnosis of syndromic craniosynostosis (CS) is important for personalized treatment, surveillance, and genetic counselling. We describe detailed clinical criteria for syndromic CS and the distribution of genetic diagnoses within the cohort. The prospective registry of the Norwegian National Unit for Craniofacial Surgery was used to retrieve individuals with syndromic CS born between 1 January 2002 and 30 June 2019. All individuals were assessed by a clinical geneticist and classified using defined clinical criteria. A stepwise approach consisting of single-gene analysis, comparative genomic hybridization (aCGH), and exome-based high-throughput sequencing, first filtering for 72 genes associated with syndromic CS, followed by an extended trio-based panel of 1570 genes were offered to all syndromic CS cases. A total of 381 individuals were registered with CS, of whom 104 (27%) were clinically classified as syndromic CS. Using the single-gene analysis, aCGH, and custom-designed panel, a genetic diagnosis was confirmed in 73% of the individuals (n = 94). The diagnostic yield increased to 84% after adding the results from the extended trio-based panel. Common causes of syndromic CS were found in 53 individuals (56%), whereas 26 (28%) had other genetic syndromes, including 17 individuals with syndromes not commonly associated with CS. Only 15 individuals (16%) had negative genetic analyses. Using the defined combination of clinical criteria, we detected among the highest numbers of syndromic CS cases reported, confirmed by a high genetic diagnostic yield of 84%. The observed genetic heterogeneity encourages a broad genetic approach in diagnosing syndromic CS.

A Pilot Study of Identification Genetic Background of Craniosynostosis Cases.

The early fusion of the cranial sutures was described as a craniosynostosis. The early diagnosis and management of craniosynostosis is very important. Environmental factors and genetic abnormalities plays a key role during the development of craniosynostosis. Syndromic craniosynostosis cases are related with autosomal dominant disorders but nearly half of the affected cases carry a new mutation. In this study, in order to identify the genetic etiology of craniosynostosis the authors analyzed 20 craniosynostosis patients by using conventional karyotype, aCGH, sanger sequencing, next generation sequencing (NGS) and Multiplex ligation-dependent probe amplification (MLPA) techniques. The authors identified mutations on FGFR2 and FGFR3 genes which were associated with Muenke syndrome, Crouzon syndrome and skeletal dysplasia syndromes. NGS applied all of the cases and 7 clinical variations in 5 different gene were detected in %20 of cases. In addition to these abnormalities; del(11)(q14.1q22.2), del(17)(q21.31), dup(22)(q13.31) and t(2;16)(q37;p13) have been identified in our cohort which are not previously detected in craniosynostosis cases. Our study demonstrates the importance of detailed genetic analysis for the diagnosis, progression and management of the craniosynostosis.

Craniosynostosis: To Study the Spectrum and Outcome of Surgical Intervention at a Tertiary Referral Institute in India.

ABSTRACTAims and Objectives:This study aimed to analyze the spectrum and surgical outcome of cases of craniosynostosis operated at a tertiary referral institute in IndiaDesign:This was a cross-sectional study.Materials and Methods:We retrospectively examined 60 cases of craniosynostosis operated at our institute from 2008 to 2014 (with a minimum follow-up of 2 years). Data was collected including name, age, gender, involved sutures, other medical conditions, whether syndromic craniosynostosis or not, whether symptoms and signs of intracranial hypertension were present or not, associated findings on magnetic resonance imaging of brain and cervico-medullary junction, type of surgery performed, age at which surgery was performed, perioperative complications (if any), and findings on follow-up. To be able to analyze the surgical results, we used the seven category classification system used by Sloan et al.Results:Craniosynostosis affected more men than women. The incidence of syndromic craniosynostosis was 11.67%. Mean age at first surgery was 3.85 years. Chiari malformation was present in 80% of the Crouzon’s syndrome cases, 62.5% of the oxycephaly cases, and 4.44% of the non-syndromic, non-oxycephaly cases. Intracranial hypertension was present in 80% of the Crouzon’s syndrome cases, 75% of the oxycephaly cases, and 6.67% of the non-syndromic, non-oxycephaly cases. Perioperative complications were present in 42.86% of the syndromic craniosynostosis cases, 50% of the oxycephaly cases, and 15.56% of the non-syndromic, non-oxycephaly cases. Compromised overall correction was present in 4 of 7 cases of syndromic craniosynostosis, 3 of 8 cases of oxycephaly, and 2 of 45 cases of non-syndromic, non-oxycephaly group.Conclusion:The study highlights the importance of educating the masses so that cases of craniosynostosis present early. The incidence of Chiari malformation, intracranial hypertension, and perioperative complications was significantly higher in the syndromic craniosynostosis and oxycephaly groups than in single-suture craniosynostosis. The best surgical outcome and the least perioperative complications were seen in the trigonocephaly group. Compromised overall correction and reoperations were more common in the syndromic and complex craniosynostosis groups than in single-suture craniosynostosis.

Mutations in TFAP2B and previously unimplicated genes of the BMP, Wnt, and Hedgehog pathways in syndromic craniosynostosis

Craniosynostosis (CS) is a frequent congenital anomaly featuring the premature fusion of 1 or more sutures of the cranial vault. Syndromic cases, featuring additional congenital anomalies, make up 15% of CS. While many genes underlying syndromic CS have been identified, the cause of many syndromic cases remains unknown. We performed exome sequencing of 12 syndromic CS cases and their parents, in whom previous genetic evaluations were unrevealing. Damaging de novo or transmitted loss of function (LOF) mutations were found in 8 genes that are highly intolerant to LOF mutation (P = 4.0 × 10-8); additionally, a rare damaging mutation in SOX11, which has a lower level of intolerance, was identified. Four probands had rare damaging mutations (2 de novo) in TFAP2B, a transcription factor that orchestrates neural crest cell migration and differentiation; this mutation burden is highly significant (P = 8.2 × 10-12). Three probands had rare damaging mutations in GLI2, SOX11, or GPC4, which function in the Hedgehog, BMP, and Wnt signaling pathways; other genes in these pathways have previously been implicated in syndromic CS. Similarly, damaging de novo mutations were identified in genes encoding the chromatin modifier KAT6A, and CTNNA1, encoding catenin α-1. These findings establish TFAP2B as a CS gene, have implications for assessing risk to subsequent children in these families, and provide evidence implicating other genes in syndromic CS. This high yield indicates the value of performing exome sequencing of syndromic CS patients when sequencing of known disease loci is unrevealing.

Suitable Indication for the Application of Distraction Osteogenesis

In recent years, cranial distraction osteogenesis (DOG) for craniosynostosis has often been performed in Japan. Since 1998, DOG has been conducted in more than 80 patients with craniosynostosis in our institution. It is now important to define the appropriate indications for the application of DOG for craniosynostosis. From the point of view of our more than 10 years of experience with the application of cranial DOG, posterior enlargement is one of the most appropriate applications. Bilateral posterior expansion is conducted for hypertension because of bilateral lambdoidal synostosis, whereas unilateral posterior expansion is conducted for asymmetry because of unilateral posterior plagiocephaly. Posterior expansion by gradual distraction was conducted for 12 cases. Eight cases of syndromic craniosynostosis and 4 of simple unilateral lambdoid synostosis were included. Clinical and radiological improvement was observed in all cases. Postdistraction computed tomography demonstrated a decrease in digital printing within a few months in all cases. Distraction osteogenesis is a useful procedure for posterior enlargement by gradual expansion and guarantees postdistraction rigidity without collapse in a supine position in bilateral and unilateral lambdoid synostosis.

Twenty-five-years follow-up results of our total cranial reshaping “bamboo-ware method”

For patients with craniosynostosis, there is no single procedure available for reconstructing a normal cranial shape, regardless of the type of deformity. To achieve ideal dynamic total skull remodeling for any type of craniosynostosis, we developed the bamboo-ware method. Using two or three coronal bars as landmarks, the anterior-posterior length of the skull was determined using the sagittal bandeau, thereby creating the basic framework for reconstruction. Bone was then bridged to the remaining defects in a manner resembling woven bamboo. We treated 30 craniosynostosis patients (20 isolated cases and 10 cases of syndromic craniosynostosis) using the bamboo-ware method. Although intracranial infection was observed in three cases during the postoperative period, no deaths or serious complications were noted. In all patients, good cranial shape and adequate cranial volume were achieved. The bamboo-ware method enabled outstanding results for every type of synostosis. This method could not only treat the deformity, but also resulted in good cranial form with a single operation.

Tracheobronchial Anomalies in Syndromic Craniosynostosis With 3-Dimensional CT Image and Bronchoscopy

Patients with syndromic craniosynostosis have many problems involving the upper airway, laryngotracheal airway, and tracheobronchial tree. Evaluation of tracheobronchial disorders in syndromic craniosynostosis is very important for accurately diagnosing these problems. We have used three-dimensional computed tomography (CT) imaging of the tracheobronchial tree (three-dimensional tracheal CT imaging) since a multidetector CT was installed in our hospital in 2004. In this study, we assessed the configuration of the tracheobronchial system using three-dimensional tracheal CT imaging and bronchoscopy.During the period from 2004 to 2009, 48 patients with syndromic craniosynostosis underwent surgery at our hospital. Of those, 16 patients required tracheostomy. These syndromic craniosynostosis cases were examined with three-dimensional tracheal CT imaging and bronchoscopy. All CT scans were performed on a multidetector CT (120 kV, 22-120 mA, 0.5 s/slice, 1-mm slice; Aquilion; Toshiba Co, Tokyo, Japan) without respiratory suppression.All 16 study patients presented with severe stenosis of the upper airway on bronchoscopic examination. Seven were confirmed to have abnormalities by both bronchoscopy and three-dimensional tracheal CT imaging. Four were confirmed to have abnormalities on either bronchoscopy or three-dimensional tracheal CT imaging, whereas 5 patients were apparently free of abnormalities as determined by both modalities.In conclusion, it was possible to accurately assess the configuration of the tracheobronchial system using both three-dimensional tracheal CT imaging and bronchoscopy. Our results suggest these examinations to be very useful for assessing the optimal timing of decannulation and respiratory function prognosis.

Hydrocephalus and craniosynostosis.

A retrospective study of 1727 cases of craniosynostosis was undertaken to determine the interrelationship between abnormal cerebrospinal fluid (CSF) hydrodynamics and craniosynostosis. The patients were divided into two groups: nonsyndromic craniosynostosis and syndromic craniosynostosis. Cases of occipital plagiocephaly without suture synostosis and cases of shunt-induced craniosynostosis were excluded from the study. The majority of patients (1297) were treated surgically for their cranial deformity; 95% of these patients had a postoperative follow-up review period lasting 5 years. Clinical and radiographic charts covering the time from presentation through the follow-up period were reviewed. Abnormal intracranial CSF hydrodynamics was found in 8.1% of the patients (3.4% of whom had received shunts and 4.5% of whom had not). Three types of CSF hydrodynamic disturbance were observed: progressive hydrocephalus with ventricular dilation, nonprogressive ventriculomegaly, and dilation of the subarachnoid spaces. Hydrocephalus occurred much more frequently in patients with syndromic craniosynostosis (12.1%) than in those with isolated craniosynostosis (0.3%). In fact, patients with kleeblattschädel exhibited hydrocephalus as a constant feature and patients with Crouzon's syndrome were far more likely to have hydrocephalus than those with other syndromes. In Apert's syndrome, ventricular dilation occurred very frequently, but it was almost always nonprogressive in nature. In most cases of syndromic craniosynostosis, venous sinus obstruction and/or chronic tonsillar herniation were found. Their role in the pathophysiology of hydrocephalus in craniosynostosis is discussed.

Hydrocephalus and craniosynostosis

ObjectA retrospective study of 1727 cases of craniosynostosis was undertaken to determine the interrelationship between abnormal cerebrospinal fluid (CSF) hydrodynamics and craniosynostosis.MethodsThe patients were divided intwo two groups: nonsyndromic craniosynostosis and syndromic craniosynostosis. Cases of occipital plagiocephaly without suture synostosis and cases of shunt-induced craniosynostosis were excluded from the study. The majority of patients (1297) were treated surgically for their cranial deformity; 95% of these patients had a postoperative follow-up review lasting 5 years. Clinical and radiographic charts covering the time from presentation through the follow-up period were reviewed.ConclusionsAbnormal intracranial CSF hydrodynamics was found in 8.1% of the patients (3.4% of whom had received shunts and 4.5% of whom had not). Three types of CSF hydrodynamic disturbance were observed: progressive hydrocephalus with ventricular dilation, nonprogressive ventriculomegaly, and dilation of the subarachnoid spaces. Hydrocephalus occurred much more frequently in patients with syndromic craniosynostosis (12.1%) than in those with isolated craniosynostosis (0.3%). In fact, patients with kleeblattschädel exhibited hydrocephalus as a constant feature and patients with Crouzon's syndrome were far more likely to have hydrocephalus than those with other syndromes. In Apert's syndrome, ventricular dilation occurred very frequently, but it was almost always nonprogressive in nature. In most cases of syndromic craniosynostosis, venous sinus obstruction and/or chronic tonsillar herniation were found. Their role in the pathophysiology of hydrocephalus in craniosynostosis is discussed.