Craniosynostosis Research Articles

Management of Sagittal and Lambdoid Craniosynostosis: Open Cranial Vault Expansion and Remodeling.

The prevalence of sagittal and lambdoid suture craniosynostosis differs considerably, as they are notably the most and least prevalent sutures involved in isolated suture craniosynostosis, respectively. The goals of reconstructing the cranial vault in both entities is the same: to release the fused suture, expand cranial volume, restore normal head shape and morphology, and allow for normal growth of the cranial vault. With regards to sagittal suture synostosis, opinions vary on whether reconstruction should focus on either the anterior or poster cranial vault. In contrast, the poster cranial vault is always targeted in lambdoid suture craniosynostosis.

Racial and Socioeconomic Disparities in Prompt Craniosynostosis Workup and Treatment.

The purpose of this study was to identify racial and socioeconomic disparities in craniosynostosis evaluation and treatment, from referral to surgery. Patients diagnosed with craniosynostosis between 2012 and 2020 at a single center were identified. Chart review was used to collect demographic variables, age at referral to craniofacial care, age at diagnosis, age at surgery, and surgical technique (open versus limited incision). Multivariable linear and logistic regression models with lasso regularization assessed the independent effect of each variable. A total of 298 patients were included. Medicaid insurance was independently associated with a delay in referral of 83 days [95% confidence interval (CI) 4-161, P=0.04]. After referral, patients were diagnosed a median of 21 days later (interquartile range 7-40), though this was significantly prolonged in patients who were not White (β 23d, 95% CI 9-38, P=0.002), had coronal synostosis (β 24d, 95% CI 2-46, P=0.03), and had multiple suture synostosis (β 47d, 95% CI 27-67, P<0.001). Medicaid insurance was also independently associated with diagnosis over 3 months of age (risk ratio 1.3, 95% CI 1.1-1.4, P=0.002) and undergoing surgery over 1 year of age (risk ratio 3.9, 95% CI 1.1-9.4, P=0.04). In conclusion, Medicaid insurance was associated with a 3-month delay in referral to craniofacial specialists and increased risk of diagnosis over 3 months of age, limiting surgical treatment options in this group. Patients with Medicaid also faced a 4-fold greater risk of delayed surgery, which could result in neurodevelopmental sequelae.

The utility and post-operative evolution of head circumference in nonsyndromic single-suture craniosynostosis: a prospective study in Vietnamese children.

Head circumference (HC) is an important clinical tool for following head growth in children with craniosynostosis (CS). The purpose of this study is to quantify the usefulness of HC along continuum of CS care, from diagnosis to pre- and post-operative (pre-op, post-op) follow-up in Vietnamese children. A prospective cohort of 54 nonsyndromic single-suture CS patients undergoing open surgery from January 2015 to January 2020 was collected at Children's Hospital 2, Vietnam. HC z-score on admission was compared with World Health Organization (WHO) standards to evaluate for utility in initial diagnosis. Pre-op and post-op HC were compared to demonstrate the evolution of head growth following reconstruction. Nonsyndromic single-suture CS was more predominant in males (79.6%) than in females (20.4%). The mean HC z-score was - 0.38 [Formula: see text] 1.29 similar to normal WHO standards regardless of which sutural involvement. The HC z-score increased above + 1 standard deviation (SD) significantly at 3months of follow-up (p < 0.001); however, the trajectory gradually decreased after the first year of surgery. One patient (1.8%, 1/54) demonstrated restenosis and delayed intracranial hypertension (DIH) 4years after reconstruction. The HC in nonsyndromic single-suture CS children presents similarly to the values of healthy children. Additionally, HC reliably increased after reconstruction and gradually normalized over subsequent years. This indicator is consistent in Southeast Asian populations and should be used to follow all patients to assess the normal progression of post-op head growth and as a useful indicator of suspected recurrent synostosis.

A child with Roberts syndrome presenting severe craniofacial anomaly

Roberts syndrome is a rare congenital anomaly which was described by John Roberts in 1919, also known as pseudothalidomidic or phocomelia. Characterized by skeletal deformities, in particular symmetric reduction of the extremities and craniofacial anomalies such as cleft lip and palate and cranio synostosis presenting more frequently, as well as bilateral symmetric short neck tetraphocomelia or hypomelia and brachydactyly. Its prevalence is unclear. As of now, 150 cases of different racial and ethnic origins have been reported in the literature. The diagnosis of Roberts Syndrome is established by cytogenetic and molecular analysis which show a phenomenon known as premature separation of the centromere or heterochromatin repulsion, constituting the main marker for Roberts syndrome. For any child with limb and craniofacial bone malformations, this syndrome should be considered as a differential diagnosis. The purpose of this study is to present a clinical case of a 2-year-old patient with Roberts Syndrome with a marked craniofacial anomaly.

Normocephalic sagittal craniosynostosis in young children is common and unrecognized

Sagittal craniosynostosis (SC) is usually diagnosed during early childhood by the presence of scaphocephaly. Recently, our group found 3.3% of children under 5years of age with normocephalic sagittal craniosynostosis (NSC) using computed tomography (CT) scans. This paper aims to validate our preliminary findings using a larger cohort of patients, and analyze factors associated with incidental NSC. A retrospective review of head CT scans in patients aged 0 to 71months who presented to the emergency department of our tertiary care institution between 2008 and 2020 was completed. Patients with syndromes associated with craniosynostosis (CS), history of hydrocephalus, or other brain/cranial abnormalities were excluded. Two craniofacial surgeons reviewed the CT scans to evaluate the presence and extent of CS. Demographic information, gestational age, past medical and family history, medications, and chief complaint were recorded as covariates, and differences between patients with and without CS were analyzed. Furthermore, comparison of the prevalence of CS across age groups was studied. Additional analysis exploring association between independent covariates and the presence of CS was performed in two sub-cohorts: patients ≤ 24months of age and patients > 24months of age. A total of 870 scans were reviewed. SC was observed in 41 patients (4.71% - 25 complete, 16 incomplete), all with a normal cranial index (width/length > 0.7). The prevalence of SC increased up to 36months of age, then plateaued through 72months of age. Patients under 2years of age with family history of neurodevelopmental disease had 49.32 (95% CI [4.28, 567.2]) times higher odds of developing CS. Sub-cohort of patients above 24months of age showed no variable independently predicted developing CS. NSC in young children is common. While the impact of this condition is unknown, the correlation with family history of neurodevelopmental disease is concerning.

25. Using 3-D Printed Models as Educational Tools: A Randomized Controlled Trial Comparing Traditional Lectures to Hands-On Methods in Craniosynostosis education.

Background: Three-dimensional (3D) printed models have been described as a tool for medical education, surgical training, pre-operative planning, research, and innovation. This study analyzes the effectiveness of using such 3D printed skull models to teach concepts central to craniosynostosis (CS) in a medical student elective course Methods: Medical students in a Plastic Surgery elective were randomly assigned to receive a traditional lecture on craniosynostosis alone (control group), or receive the lecture plus participate in a hands-on session using 3D printed skull models demonstrating craniosynostosis (intervention group). Prior to this study, the senior author collaborated with the Department of Radiology at a large tertiary care urban children’s hospital to have 12 models 3D printed from computed tomography (CT) scans of representative craniosynostosis patients. Pathologies represented include sagittal, metopic, lambdoid, unicoronal, and bicoronal craniosynostosis as well as pansynostosis resulting in Kleeblattschadel skull. Three of the skulls demonstrate post-operative changes following surgery for craniosynostosis with reconstructive techniques including strip craniectomy, modified Pi procedure, and frontoorbital advancement. A 23-question test evaluating knowledge of CS was administered at three timepoints: prior to the course, after the lecture +/- the intervention, and three weeks later. Statistical analysis compared test performance between cohorts. Results: 21 students were enrolled; 11 were randomized to the control group, 10 to the intervention group. Test 1 (pre-intervention) showed no significant difference in the mean overall score (defined as total percent of correct answers) between groups (control=61%, intervention=57% correct; p=0.67). On Test 2 (post-intervention), both groups had significant increases in overall score. The control group improved by 21.3% (p=0.004) and the intervention group improved by 34.4% (p=0.002). Moreover, the mean score for the intervention group was significantly higher compared to that of the controls, with 92.1% correct versus 82.6% (p=0.041). Test 3 overall scores were not statistically different from test 2 scores, indicating little temporal decay. Students were highly satisfied with the quality and content of the intervention. Conclusion: 3D printed skull models are effective educational adjuncts in craniofacial surgery. 3D printing technology is an inexpensive tool with high satisfaction rates that can be increasingly applied to medical student and resident education.

Craniofacial reconstructions in children with craniosynostosis

Craniosynostosis is a rare congenital disease of the skull. They arise when one or more cranial sutures ossify prematurely. This causes an obstruction to normal brain growth and leads to specific deformations of the skull, which may result in intracranial hypertension and cognitive delay. We have retrospectively analysed all children treated at the Unit of paediatric neurosurgery of the University Medical Centre Ljubljana between June 2015 and September 2020. The following items have been recorded: affected suture, underlying syndromic condition, hydrocephalus, Chiari malformation, raised intracranial pressure, age at surgery, surgical technique, need for multiple operations and surgical complications. During the study period, 71 children have been treated for craniosynostosis. The median postoperative follow-up was 31 months. There were: 54.9% sagittal, 25.3% metopic, 14.0% unicoronal, 1.4% bicoronal and 1.4% unilateral lambdoid craniosynostosis. Multiple sutures were affected in 2.8% cases. 7.0% of the cases were syndromic. Overall, 74 surgical procedures have been performed: frontoorbital advancement represented 40.5% of them; biparietal remodelling 32.4%: total cranial vault remodelling 22.9%; posterior distraction 2.7%; posterior expansion 1.3%. Median age at surgery was 12.8 months. The treatment of craniosynostosis is surgical and requires a multidisciplinary approach, with expertise in plastic and reconstructive surgery, maxillofacial surgery and neurosurgery. The aim of surgical treatment is to release the constrictive and deformative effect that the synostosis has on skull growth. This requires a remodelling of the neurocranium and, if necessary, of the viscerocranium. Beyond aesthetic purposes, the primary aim of surgical treatment is to permit a normal development of the brain.

UCSQ Method Applied on 3D Photogrammetry: Non-Invasive Objective Differentiation Between Synostotic and Positional Plagiocephaly.

Objective differentiation between unilateral coronal synostosis (UCS) and positional posterior plagiocephaly (PPP) based on 3D photogrammetry according to Utrecht Cranial Shape Quantificator (UCSQ). Retrospective study. Primary craniofacial center. Thirty-two unoperated patients (17 UCS; 15 PPP) (age < 1 year). Extraction of variables from sinusoid curves derived using UCSQ: asymmetry ratio forehead and occiput peak, ratio of gradient forehead and occiput peak, location forehead and occiput peak. Variables, derived using 3D photogrammetry, were analyzed for differentiation between UCS and PPP. Frontal peak was shifted to the right side of the head in left-sided UCS (mean x-value 207 [192-220]), and right-sided PPP (mean x-value 210 [200-216]), and to the left in right-sided UCS (mean x-value 161 [156-166]), and left-sided PPP (mean x-value 150 [144-154]). Occipital peak was significantly shifted to the right side of the head in left-sided PPP (mean x-value 338 [336-340]) and to the left in right-sided PPP (mean x-value 23 [14-32]). Mean x-value of occipital peak was 9 (354-30) in left- and 2 (350-12) in right-sided UCS. Calculated ratio of gradient of the frontal peak is, in combination with the calculated asymmetry ratio of the frontal peak, a distinctive finding. UCSQ objectively captures shape of synostotic and positional plagiocephaly using 3D photogrammetry, we therefore developed a suitable method to objectively differentiate UCS from PPP using radiation-free methods.

Wormian bones and nonsyndromic craniosynostosis: A comparative study using computed tomography

Introduction: Wormian bones (WB) are accessory bones positioned within the sutures or fontanelles. Although several studies have associated them with genetic disorders, ethnicity, and skull deformations, their relationship with nonsyndromic craniosynostosis (CS) has not been established, especially among Brazilians. Therefore, this study was conducted to analyze the incidence and association of WB with nonsyndromic CS in Brazilian children.&#x0D; Methods: An observational and retrospective study was conducted using computed tomography with 3D reconstruction in Brazilian children aged &lt;3 years to compare the incidence and number of WB between regular children (group 1) and those with nonsyndromic CS (group 2).&#x0D; Results: A total of 140 children, comprising 62.9% boys (p &lt; 0.001) with a mean age of 8.78 months, were included in this study. The most common types of CS were trigonocephaly (34; 48.6%), scaphocephaly (25; 35.7%), anterior plagiocephaly (5; 7.1%), posterior plagiocephaly (3; 4.2%), and brachycephaly (3; 4.2%). WB were more common in regular children (41; 58.6%) than in children with CS (28; 40.0%) (p = 0.028). Regular children had an average of 2.12 WB versus 1.32 WB in children with nonsyndromic CS (p = 0.024).&#x0D; Conclusion: The significantly less incidence of WB in Brazilian children with nonsyndromic CS was quite different from that reported in other studies and could indicate the tendency of this disease to have disturbance in ossification of the cranial vault, the impact of ethnicity, and probably the lack of additional compensatory skull growth.&#x0D; &#x0D;

Surgical Technique in Pediatric Craniofacial Surgery

The surgical correction of non-syndromic and syndromic craniosynostoses (CS) presents several challenges mainly related to the complexity of skull reconstruction, along with the risk of blood loss. Moreover, the surgical team has the commitment to achieve pleasant cosmetic results while minimizing morbimortality. Additionally, several strategies and instruments have been developed to handle this concern, such as technical surgery with minimal bleeding and piezo surgery and technique to obtain more bone autografts and minimize bone healing disturbances. This study was designed to present such techniques in a comprehensive revision of literature and describe them in a step-by-step fashion according to the current state of the art and the experience of pediatric neurosurgery in a single Brazilian institution.

Targeted Sequencing of Candidate Regions Associated with Sagittal and Metopic Nonsyndromic Craniosynostosis.

Craniosynostosis (CS) is a major birth defect in which one or more skull sutures fuse prematurely. We previously performed a genome-wide association study (GWAS) for sagittal non-syndromic CS (sNCS), identifying associations downstream from BMP2 on 20p12.3 and intronic to BBS9 on 7p14.3; analyses of imputed variants in DLG1 on 3q29 were also genome-wide significant. We followed this work with a GWAS for metopic non-syndromic NCS (mNCS), discovering a significant association intronic to BMP7 on 20q13.31. In the current study, we sequenced the associated regions on 3q29, 7p14.3, and 20p12.3, including two candidate genes (BMP2 and BMPER) near some of these regions in 83 sNCS child-parent trios, and sequenced regions on 7p14.3 and 20q13.2-q13.32 in 80 mNCS child-parent trios. These child-parent trios were selected from the original GWAS cohorts if the probands carried at least one copy of the top associated GWAS variant (rs1884302 C allele for sNCS; rs6127972 T allele for mNCS). Many of the variants sequenced in these targeted regions are strongly predicted to be within binding sites for transcription factors involved in craniofacial development or bone morphogenesis. Variants enriched in more than one trio and predicted to be damaging to gene function are prioritized for functional studies.

Dissecting the Role of the Six1‐Associated Genes in Craniofacial Development and Disease

Genetic variants of SIX1, a transcription factor implicated in many cellular processes during craniofacial development, and of its co‐factor EYA1 underlie 50% of Branchio‐oto‐renal syndrome (BOR) cases. BOR is an autosomal dominant disorder characterized by various craniofacial defects, including malformed middle ear ossicles leading to conductive hearing loss. Interestingly, some BOR variants in SIX1 also underlie craniosynostosis (CRS) which indicates that SIX1 has a crucial role in craniofacial bone development. One important aspect of SIX1 function is that it interacts with co‐factors that can induce or repress its transcriptional activity. In this work, we expand our knowledge of the Six1 gene regulatory network with respect to craniofacial development. We first used a Six1 knockout mouse line to assess gene expression profiles of dissected E10.5 mandibular arches which give rise to the middle ear ossicles and lower jaw, via RNA‐sequencing. Our transcriptomic analysis led to the identification of 122 genes, including components of the FGF and WNT signaling pathways, known contributors to craniofacial bone development. In parallel, we used in vitro studies to characterize three novel co‐factors of Six1: Sobp, Mcrs1 and Pa2g4 that were recently identified in Xenopus. Our findings indicate that Sobp and Mcrs1 are bona fide Six1 co‐factors in mouse. We are now studying the genes identified in the RNA‐seq and the novel Six1 co‐factors using in vitro culture of mouse pre‐osteoblastic cells (MC3T3‐E1) to identify their role in bone formation. Altogether, our results identified novel Six1‐associated genes that are potential candidate genes for the unresolved cases of BOR and CRS.

School-age outcomes in patients with unilateral coronal synostosis: comparison of fronto-orbital advancement and endoscopic strip craniectomy.

Outcomes research on unilateral coronal synostosis is mostly limited to the early postoperative period. This study examines facial asymmetry, desire for revision, and patient-reported outcomes at school age in children who received either endoscopic strip craniectomy with helmet therapy or fronto-orbital advancement (open repair). Patients with repaired unilateral coronal synostosis born between 2000 and 2017, with 3D photographs taken when they were between 3.5 and 8 years of age, were eligible for study inclusion. Three pairs of bilateral linear measurements and two angular measurements were taken. Parent- and physician-reported desire for revision and patient-reported outcomes (Patient-Reported Outcomes Measurement Information System cognitive function and Quality of Life in Neurological Disorders stigma scores) were collected from patient charts. Thirty-five patients qualified, including 25 with open repair and 10 with endoscopic repair. The median patient ages at repair were 3 months and 8 months in the endoscopic and open groups, respectively. The average ages at final 3D photography were 5.8 years and 5.5 years in the endoscopic and open groups, respectively. Digital anthropometry revealed no significant differences in measures of facial asymmetry between the repair groups (p ≥ 0.211). Midface depth (tragion to subnasale) was significantly less symmetric at school age than other linear measures (F(2,102) = 9.14, p < 0.001). Forehead asymmetry was significantly associated with parent- and physician-reported desire for revision (p ≤ 0.006). No significant associations were found between physical asymmetry and patient-reported stigma or cognitive function (p > 0.046, Holm-Bonferroni correction). Children who underwent open or endoscopic repair for unilateral coronal synostosis have comparable facial symmetry at school age, but midface depth remains highly asymmetrical in both groups. Forehead asymmetry at school age correlates with parent- and physician-reported desire for revision.

Results from Genetic Studies in Patients Affected with Craniosynostosis: Clinical and Molecular Aspects.

Background: Craniosynostosis (CS) represents a highly heterogeneous genetic condition whose genetic background has not been yet revealed. The abnormality occurs either in isolated form or syndromic, as an element of hundreds of different inborn syndromes. Consequently, CS may often represent a challenging diagnostic issue. Methods: We investigated a three-tiered approach (karyotyping, Sanger sequencing, followed by custom gene panel/chromosomal microarray analysis, and exome sequencing), coupled with prioritization of variants based on dysmorphological assessment and description in terms of human phenotype ontology. In addition, we have also performed a statistical analysis of the obtained clinical data using the nonparametric test χ2. Results: We achieved a 43% diagnostic success rate and have demonstrated the complexity of mutations’ type harbored by the patients, which were either chromosomal aberrations, copy number variations, or point mutations. The majority of pathogenic variants were found in the well-known CS genes, however, variants found in genes associated with chromatinopathies or RASopathies are of particular interest. Conclusion: We have critically summarized and then optimised a cost-effective diagnostic algorithm, which may be helpful in a daily diagnostic routine and future clinical research of various CS types. Moreover, we have pinpointed the possible underestimated co-occurrence of CS and intellectual disability, suggesting it may be overlooked when intellectual disability constitutes a primary clinical complaint. On the other hand, in any case of already detected syndromic CS and intellectual disability, the possible occurrence of clinical features suggestive for chromatinopathies or RASopathies should also be considered.

Thyroxine Metabolism in an Avian Model of Induced Thyrotoxicosis

Craniosynostosis (CS) is the premature fusion of cranial sutures which leads to abnormal cranial structure and causes abnormal neurocognition and behavior. Maternal thyroid disorders are associated with incidence of CS in infants. However, the mechanism of TH-induced CS is still obscure. Thyroxine (T4) metabolism is regulated by the expression of deiodinases. Type I and type II deiodinases (DIO1 and DIO2) remove iodine from T4 producing active triiodothyronine (T3). Deiodinase III (DIO3) inactivates both T4 and T3. Our lab is establishing a model to study the effects of thyrotoxicosis induced CS using fertilized chicken eggs. Eggs were injected into the air cell with either saline or 25 ng T4 on days E11 and E15 of embryonic development. Heart rates were measured daily from EKG recordings and on E19, tissue samples were collected for qRT-PCR analysis. The main objective was to validate the induced state of thyrotoxicosis by evaluating negative feedback mechanisms of thyroid hormone regulation following exposure by measuring expression of DIO1 and DIO3 in embryonic livers. Since livers are the main site of metabolism, we hypothesize that levels of DIO3 will increase following thyroxine exposure. Results demonstrated a significant upregulation of DIO3 2 days after exposure and a significant downregulation 4 days following exposure. No significant differences were observed in DIO1 on any of the days after exposure. These results, along with correlating heart rates, support our model by of induced thyrotoxicosis by demonstrating the metabolism of thyroxine in response to our treatment regimen.&#x0D; &#x0D; &#x0D; Acknowledgment of NASA West Virginia Space Grant Consortium (Grant #80NSSC20M0055) and the Genomics Core Facility and WV-INBRE (NIH grant P20GM103434).&#x0D;

Identifying Positive Cases in an Avian Model of Induced-Thyrotoxicosis

Thyrotoxicosis is a condition of excess circulating thyroid hormones. Maternal thyrotoxicosis has been related to the development of craniosynostosis (CS) in approximately 3% of births. CS occurs when the cranial sutures of the skull fuse prematurely. However, the mechanism for thyroid hormone-induced CS in those cases is unclear. Currently, we are establishing an avian model of thyroxine-induced CS to study these mechanisms. Two groups of fertilized chicken eggs were injected with saline or 25 ng T4 (thyroxine) on embryonic days 11 and 15 and collected on 19 prior to hatching. Data were collected from each group including: body mass and length, tibia and femur length, liver and heart mass, and circulating T4 concentrations. Our study aimed to characterize all possible physiological changes associated with our treatment and determine the subset of positive cases. Following thyroxine exposure, 19-day old embryos were 4% shorter (p&lt;0.05) with a corresponding 8% decrease in tibia length (p&lt;0.01) and 9% decrease in femur length (p&lt;0.01) compared to the controls. Measured T4 concentrations were 88% higher in serum samples following thyroxine-exposure compared to the controls (p&lt;0.01). Body, heart, and liver mass were not different between groups. We were then able to isolate positive cases from correlation plots based on clustering observed in anticipated regions. In conclusion these results support that there is a subset of samples within the treatment group that display the expected phenotypes. It is in this subgroup of data that our focus can be shifted to study the mechanism of thyroxine-induced CS.&#x0D; Acknowledgment of NASA West Virginia Space Grant Consortium (Grant #80NSSC20M0055) and the Genomics Core Facility and WV-INBRE (NIH grant P20GM103434).

Analysis of differential morphology of the anterior fontanelle in an embryonic avian model of induced thyrotoxicosis

Craniosynostosis (CS) occurs when the cranial sutures of the skull fuse prematurely, and this results in intracranial pressure during development and skull deformities. Maternal hyperthyroidism during embryonic development has been linked to the development of CS. Our lab is currently establishing a model of thyroxine-induced CS to study the mechanism involved in thyroxine-enhanced cranial ossification. Two groups of fertilized chicken eggs were injected with saline or 25 ng T4 into the air cell on embryonic days 11 and 15. Skulls from each group were collected on embryonic days 17 through 19 (n = 17-21 per day). They were fixed in formalin and processed using Alizarin Red whole-mount staining to image and quantify any morphological differences in the ossifying membrane of the anterior fontanelle between the treatment and control groups. We hypothesize that thyroxine exposure will alter skull morphology. Geometric morphometric analysis using MorphoJ was performed to identify shape variation between treatment groups of the fibrous space and ossifying region of the anterior fontanelle. Significance was determined by Procrustes ANOVA. Results demonstrated a significant variation in shape of the fibrous gap between developing sutures on embryonic days 17, 18 and 19 (p&lt;0.05) and a significant variation in the shape of the ossifying region on embryonic days 18 and 19 (p&lt;0.001). In conclusion, we determined our model of induced thyrotoxicosis successfully altered skull morphology visualized in the anterior fontanelle. These findings support that our model is successful in promoting the fusing of the cranial bones with thyroxine exposure in our avian model.&#x0D; Acknowledgment of NASA West Virginia Space Grant Consortium (Grant #80NSSC20M0055) and the Genomics Core Facility and WV-INBRE (NIH grant P20GM103434).

The outcome of targeted NGS screening in patients with syndromic forms of sagittal and pansynostosis - IL11RA is an emerging core-gene for pansynostosis

Here, we have studied the prevalence and spectrum of genetic alterations in syndromic forms of sagittal and pansynostosis. Eighteen patients with sagittal synostosis (isolated or combined with other synostoses, except coronal) or pansynostosis were phenotypically assessed by retrospective analysis of medical records, three-dimensional computed tomography skull reconstructions, and registered photos. Patient DNAs were analyzed using a targeted next-generation sequencing (NGS) panel including 63 craniosynostosis (CS) related genes. Pathogenic and likely pathogenic variants were found in 72% of the cases, mainly affecting FGFR2, TWIST1, IL11RA, and SKI. Two patients that were negative at NGS screening – one with a supernumerary marker chromosome with duplication of 15q25.2q26.3 and one with a pathogenic PHEX variant – were identified using microarray and single gene analysis, respectively. The overall diagnostic rate in the cohort was thus 83%. We identified two novel likely pathogenic variants in FGFR2 (NM_022970.3: c.811_812delGGinsCC, p.Gly271Pro) and TWIST1 (NM_000474.3: c.476T > A, p.Leu159His), and a novel variant of unclear phenotypic significance in RUNX2 (NM_001024630.3: c.340G > A, p.Val114Ile) which could suggest a modulatory effect. Notably, we also identified three new patients with pansynostosis and a Crouzon-like phenotype with IL11RA mutation. Targeted NGS using a broad panel of CS-related genes is a simple and powerful tool for detecting pathogenic mutations in patients with syndromic forms of CS and multiple suture involvement, in particular pansynostosis. Our results provide additional evidence of an association between pansynostosis and IL11RA, an emerging core gene for autosomal recessive CS.

Cloverleaf Skull Syndrome: A Rare Case Report

Cloverleaf deformity is an extremely rare skull deformity that occurs when several joints (sutures) between a baby's skull bones begin to fuse too early. Also known as Kleeblattschädel syndrome, the cloverleaf deformity causes bulging at the front and sides of the skull, resembling a cloverleaf shape. Cloverleaf skull syndrome is an abnormal configuration of the calvaria classified as craniosynostosis, consisting of premature ossification of cranial sutures. It is a deformity characterized by a remarkable enlargement of the head, with a trilobed configuration of the frontal view, resembling a three leaved clover(1) The first report about such a syndrome in the literature occurred in 1973 and, over the years only some tens of cases have been documented worldwide(3). The present report describes a case of a severe craniofacial condition that is known as "cloverleaf skull syndrome". At Physical examination multiple malformations were observed, with altered craniofacial configuration, low set ear, hypertelorism, exopthalmos, syndactyly, closed anterior fontanelle, high arched palate, bilateral CTEV. The vast majority of patients with kleeblattschädel have intellectual impairment and hydrocephalus. It is usually seen in thanatophoric dysplasia: classically type II only, severe Apert syndrome, severe Crouzon syndrome, Boston-type craniosynostosis &amp; Carpenter syndrome.(5)Craniosynostosis has an incidence of 1 in 2100 to 1 in 2500 live births with multi-suture craniosynostosis constituting about 5% of all the cases [9]. This condition is associated with a variety of presentations including optic atrophy, hydrocephalus, respiratory problems, cleft palate, and disorders of hearing and speech.[10] These cases are very rare &amp; so shall be reported promptly to deal with management part of this disease. An expert team of maxillofacial, plastic, and neurosurgeons is needed to handle such complex conditions which involve the correction of the bony deformity.

196 Multi-omic Convergence of Human Craniosynostosis Genes Within a Developmental Bone-Dura-Brain Nexus

INTRODUCTION: Craniosynostosis (CS) is the premature fusion of the calvarial sutures and has long been considered mostly an aesthetic disorder, despite many affected children experiencing neurocognitive deficiencies and seizures. The two types of CS, syndromic and non-syndromic, present with significant genetic clinical heterogeneity, suggesting a complex interplay of genetic and environmental causes. Given the neurodevelopmental symptoms observed in CS patients, we hypothesized the genes involved in the pathophysiology of CS may play a key role in the functional development of the brain. METHODS: We applied a multimodal integrative genomic approach to examine the functional relationships as well as the spatiotemporal and cellular interactions of all currently known craniosynostosis-associated genes (CSGs) and also explored whether they are linked to other neurodevelopmental disorders (NDD). To this end, we constructed gene co-expression modules using a bulk-RNA expression dataset with 27 human brains encompassing 16 human brain regions across fetal development into early childhood. We further used scRNA-seq datasets derived from embryonic mouse meninges, calvarial sutures and developmental human brain to identify cell-types enriched with CSGs. RESULTS: The set of co-expression modules significantly enriched with CSGs were highly expressed during mid-gestation and in primary motor, somatosensory and prefrontal cortices, and the ganglionic eminence. Moreover, some of these modules were also significantly enriched with autism-spectrum disorder (ASD) and NDD genes. The most significant modules were associated with histone-3 lysine-4 methylation, neural crest differentiation, endochondral ossification and reactive astrogliosis. The mouse meninges scRNAseq analysis showed enrichment in pial and dural fibroblasts. The whole-brain scRNA-seq analysis showed CSGs were enriched in medial ganglionic eminence (MGE)-derived cortical interneurons, astrocytes and oligodendrocyte precursors during mid-fetal brain development. CONCLUSION: CSGs may contribute to pathogenesis through epigenetic dysregulation, disrupted neural crest differentiation facilitated by neuroglial cells and MGE interneuron migration very early during development. These processes are in confluence with premature suture fusion mediated by dural and pial fibroblasts.