Language Development, Hearing Loss, and Intracranial Hypertension in Children With TWIST1-Confirmed Saethre-Chotzen Syndrome

Tmco1-Deficient Mice Exhibit a High Incidence of Otitis Media Associated with Impaired Bone Homeostasis in the Middle Ear

Craniofacial dysmorphism, skeletal anomalies, and impaired intellectual development syndrome (CFSMR1; Online Inheritance in Man number 213980) is characterized by craniofacial dysmorphism, skeletal anomalies, and mental retardation. However, reports of hearing issues have been limited. To investigate hearing-related aspects of CFSMR1, Tmco1 knockout mice (Tmco1-/-) exhibiting similar symptoms to human patients were used in this study. Otitis media (OM) was discovered in approximately 80% of Tmco1-/- mice, which led to moderate conductive hearing loss at 3 months old and further progressed to deafness 2 months later. Pathology studies of Tmco1-/- mice revealed a thickened middle ear (ME) epithelium and pronounced inflammatory infiltrates in the ME cavity and Eustachian tube of Tmco1-/- OM mice. Micro-computed tomography scan of 5-month-old Tmco1-/- OM mice showed significantly reduced ME volume and ME malformation. Tartrate-resistant acid phosphatase and Runt-related transcription factor 2, receptor activator of NF-κB ligand expression in ME revealed increased osteoclast activity and significantly decreased bone formation, suggesting potential causes of ME malformation. This study represents the first report of the audiological characteristics and the elucidation of potential mechanisms in Tmco1-/- mice. It enriches our understanding of the phenotypes associated with CFSMR1 in the field of otology and provides a promising model for chronic OM with conductive hearing loss.

TWIST1 Gene Variants Cause Craniosynostosis with Limb Abnormalities in Asian Patients

The TWIST1 gene codes for a highly conserved transcription factor in a basic helix-loop-helix transcription factors family. The pattern of inheritance is autosomal dominant in Saethre-Chotzen syndrome, Robinow-Sorauf syndrome, and Sweeney-Cox syndrome. Major features of these syndromes include coronal synostosis, vision problems, and deafness, and facial features include hypertelorism, low-set ears, arched eyebrows, beaked nose, maxillary hypoplasia, and other dysmorphisms including broad great toes, clinodactyly, brachydactyly, and cutaneous syndactyly. TWIST1 (bHLH) transcription factor regulates the formation of head and limbs in the embryo. We describe three families affected with craniosynostosis in whom a sporadic TWIST1 variant was identified on whole exome sequencing, chromosomal microarray, and Sanger sequencing.

RhoA/ROCK-TAZ Axis regulates bone formation within calvarial trans-sutural distraction osteogenesis

BACKGROUND

Craniofacial skeletal deformities can be addressed by applying tensile force to sutures to prompt sutural bone formation. The intricate process of mechanical modulation in craniofacial sutures involves complex biomechanical signal transduction. The small GTPase Ras homolog gene family member A (RhoA) functions as a key mechanotransduction protein, orchestrating the dynamic assembly of the cytoskeleton by activating the Rho-associated coiled-coil containing protein kinase (ROCK). Transcriptional coactivator with PDZ-binding motif (TAZ) serves as a crucial mediator in the regulation of genes and the orchestration of biological functions within the mechanotransduction signaling pathway. However, the role of RhoA/ROCK-TAZ in trans-sutural distraction osteogenesis has not been reported.

METHODS

We utilized pre-osteoblast-specific RhoA deletion mice to establish an in vivo calvarial trans-sutural distraction model and an in vitro mechanical stretch model for pre-osteoblasts isolated from neonatal mice. Micro-CT and histological staining were utilized to detect the formation of new bone in the sagittal suture of the skull as well as the activation of RhoA, Osterix and TAZ. The activation of ROCK-limk-cofilin and the nuclear translocation of TAZ in pre-osteoblasts under mechanical tension were detected through Western blot, qRT-PCR, and immunofluorescence.

RESULTS

The osteogenic differentiation of pre-osteoblasts was facilitated by mechanical tension through the activation of RhoA and Rho-associated kinase (ROCK), while ablation of RhoA impaired osteogenesis by inhibiting pre-osteoblast differentiation after suture expansion. Furthermore, inhibiting RhoA expression could block tensile-stimulated nuclear translocation of TAZ by preventing F-actin assembly through ROCK-LIM-domain kinase (LIMK)-cofilin pathway. In addition, the TAZ agonist TM-25659 could attenuate impaired osteogenesis caused by ablation of RhoA in pre-osteoblasts by increasing TAZ nuclear accumulation.

CONCLUSIONS

This study demonstrates that mechanical stretching promotes the osteogenic differentiation of pre-osteoblasts in trans-sutural distraction osteogenesis, and this process is mediated by the RhoA/ROCK-TAZ signaling axis. Overall, our results may provide an insight for potential treatment strategies for craniosynostosis patients through trans-sutural distraction osteogenesis.

Speech and Language Development, Hearing, and Feeding in Patients With Genetically Confirmed Crouzon Syndrome With Acanthosis Nigricans: A 36-Year Longitudinal Retrospective Review of Patients at the Oxford Craniofacial Unit

OBJECTIVE

Crouzon syndrome with acanthosis nigricans (CAN) is caused by the specific mutation c.1172C>A (p.Ala391Glu) in the fibroblast growth factor receptor 3 gene, and has an estimated prevalence of 1:1,000,000 births. Most cases occur de novo; however, autosomal dominant inheritance may occur. The clinical presentation typically includes craniosynostosis, midface and maxillary hypoplasia, choanal atresia/stenosis, hydrocephalus, and intracranial hypertension. Patients develop acanthosis nigricans, a hyperkeratotic skin disorder. The authors present the first known study to investigate the speech, language, hearing, and feeding of patients with CAN.

METHODS

A retrospective case-note review of patients with a genetically confirmed diagnosis of CAN attending the Oxford Craniofacial Unit during a 36-year period (1987-2023) was undertaken.

RESULTS

Participants were 6 patients with genetically-confirmed CAN (5 females, 1 male), all cases arose de novo. All patients had craniosynostosis (n = 5/6 multisuture synostosis, n = 1/6 left unicoronal synostosis). Hydrocephalus was managed through ventriculoperitoneal shunt in 67% (n = 4/6) of patients, and 67% (n = 4/6) had a Chiari 1 malformation. Patients had a complex, multifactorial feeding history complicated by choanal atresia/stenosis (100%; n = 6/6), and significant midface hypoplasia. All patients required airway management through tracheostomy (83%; n = 5/6); and/or continuous positive airway pressure (67%; n = 4/6). All patients underwent adenotonsillectomy (100%; n = 6/6). Initial failure to thrive, low weight, and/or height were seen in 100% (n = 6/6) patients; 80% (n = 4/5) had reflux; 100% (n = 6/6) had nasogastric, or percutaneous endoscopic gastrostomy based feeding during their treatment journey. All patients had hearing loss (100%; n = 6/6). Early communication difficulties were common: receptive language disorder (50%; n = 3/6); expressive language disorder (50%; n = 3/6); and speech sound disorder in 50% (n = 3/6)-necessitating the use of Makaton in 80% of patients (n = 3/5).

CONCLUSIONS

Patients with CAN experience significant respiratory, neurological, and structural obstacles to hearing, speech, language, and feeding. The authors present a recommended pathway for management to support patients in these domains.

What We Know About Intracranial Hypertension in Children With Syndromic Craniosynostosis

OBJECTIVE

A scoping review of literature about mechanisms leading to intracranial hypertension (ICH) in syndromic craniosynostosis (sCS) patients, followed by a narrative synopsis of whether cognitive and behavioral outcome in sCS is more related to genetic origins, rather than the result of ICH.

METHODS

The scoping review comprised of a search of keywords in EMBASE, MEDLINE, Web of science, Cochrane Central Register of Trials, and Google scholar databases. Abstracts were read and clinical articles were selected for full-text review and data were extracted using a structured template. A priori, the authors planned to analyze mechanistic questions about ICH in sCS by focusing on 2 key aspects, including (1) the criteria for determining ICH and (2) the role of component factors in the Monro-Kellie hypothesis/doctrine leading to ICH, that is, cerebral blood volume, cerebrospinal fluid (CSF), and the intracranial volume.

RESULTS

Of 1893 search results, 90 full-text articles met criteria for further analysis. (1) Invasive intracranial pressure measurements are the gold standard for determining ICH. Of noninvasive alternatives to determine ICH, ophthalmologic ones like fundoscopy and retinal thickness scans are the most researched. (2) The narrative review shows how the findings relate to ICH using the Monro-Kellie doctrine.

CONCLUSIONS

Development of ICH is influenced by different aspects of sCS: deflection of skull growth, obstructive sleep apnea, venous hypertension, obstruction of CSF flow, and possibly reduced CSF absorption. Problems in cognition and behavior are more likely because of genetic origin. Cortical thinning and problems in visual function are likely the result of ICH.

What Every Internist-Endocrinologist Should Know about Rare Genetic Syndromes in Order to Prevent Needless Diagnostics, Missed Diagnoses and Medical Complications: Five Years of 'Internal Medicine for Rare Genetic Syndromes'

Patients with complex rare genetic syndromes (CRGS) have combined medical problems affecting multiple organ systems. Pediatric multidisciplinary (MD) care has improved life expectancy, however, transfer to internal medicine is hindered by the lack of adequate MD care for adults. We have launched an MD outpatient clinic providing syndrome-specific care for adults with CRGS, which, to our knowledge, is the first one worldwide in the field of internal medicine. Between 2015 and 2020, we have treated 720 adults with over 60 syndromes. Eighty-nine percent of the syndromes were associated with endocrine problems. We describe case series of missed diagnoses and patients who had undergone extensive diagnostic testing for symptoms that could actually be explained by their syndrome. Based on our experiences and review of the literature, we provide an algorithm for the clinical approach of health problems in CRGS adults. We conclude that missed diagnoses and needless invasive tests seem common in CRGS adults. Due to the increased life expectancy, an increasing number of patients with CRGS will transfer to adult endocrinology. Internist-endocrinologists (in training) should be aware of their special needs and medical pitfalls of CRGS will help prevent the burden of unnecessary diagnostics and under- and overtreatment.

Epithelial mesenchymal transition regulator TWIST1 transcription factor stimulates glucose uptake through upregulation of GLUT1, GLUT3, and GLUT12 in vitro

TWIST1 is a major regulator of epithelial mesenchymal transition process, essential in cancer metastasis. Cancer cells increase glucose uptake capabilities to meet their high energy requirements. In this study, we explored the potential role of TWIST1 on glucose transport into the 293T cells in an insulin-dependent and insulin-independent manner. For this purpose, the ectopic expression of TWIST1 was successfully performed by electroporation. The altered mRNA expressions of GLUT-1, -3, -4, and -12, insulin receptor (InsR), and insulin receptor substrate (IRS)-1 and -2 were assessed in control and TWIST1-overexpressing cells. Glucose uptake rates of the cells were evaluated by fluorometric glucose uptake assay. Our findings showed that the transcriptional expression levels of GLUT-1, -3, and -12 genes were significantly upregulated by TWIST1. However, TWIST1 did not alter the mRNA and protein expressions of the InsR, its substrates (IRS-1 and -2), and GLUT-4 genes in 293T cells which are main factors for insulin-stimulated glucose uptake pathway. Also, the glucose transport activities were significantly increased in TWIST1-overexpressing cells compared to controls due to fetal bovine serum (FBS) stimulation, but there was a slight non-significant difference in insulin stimulation. Thus, our data suggest that TWIST1 could promote glucose uptake independently of insulin and is possible to be evaluated as a metabolic marker in cancer. Further investigations are needed to clarify the precise molecular mechanisms underlying the cells' glucose uptake and consumption during tumorigenesis.

Symmetry and Aesthetics in Dentistry

Animal bodies in general and faces in particular show mirror symmetry with respect to the median-sagittal plane, with exceptions rarely occurring. Bilateral symmetry to the median sagittal plane of the body also evolved very early. From an evolutionary point of view, it should therefore have fundamental advantages, e.g., more effective locomotion and chewing abilities. On the other hand, the recognition of bilaterally symmetric patterns is an important module in our visual perception. In particular, the recognition of faces with different spatial orientations and their identification is strongly related to the recognition of bilateral symmetry. Maxillofacial surgery and Dentistry affect effective masticatory function and perceived symmetry of the lower third of the face. Both disciplines have the ability to eliminate or mitigate asymmetries with respect to form and function. In our review, we will demonstrate symmetric structures from single teeth to the whole face. We will further describe different approaches to quantify cranial, facial and dental asymmetries by using either landmarks or 3D surface models. Severe facial asymmetries are usually caused by malformations such as hemifacial hyperplasia, injury or other diseases such as Noma or head and neck cancer. This could be an important sociobiological reason for a correlation between asymmetry and perceived disfigurement. The aim of our review is to show how facial symmetry and attractiveness are related and in what way dental and facial structures and the symmetry of their shape and color influence aesthetic perception. We will further demonstrate how modern technology can be used to improve symmetry in facial prostheses and maxillofacial surgery.

Cranial Suture Regeneration Mitigates Skull and Neurocognitive Defects in Craniosynostosis

Craniosynostosis results from premature fusion of the cranial suture(s), which contain mesenchymal stem cells (MSCs) that are crucial for calvarial expansion in coordination with brain growth. Infants with craniosynostosis have skull dysmorphology, increased intracranial pressure, and complications such as neurocognitive impairment that compromise quality of life. Animal models recapitulating these phenotypes are lacking, hampering development of urgently needed innovative therapies. Here, we show that Twist1+/- mice with craniosynostosis have increased intracranial pressure and neurocognitive behavioral abnormalities, recapitulating features of human Saethre-Chotzen syndrome. Using a biodegradable material combined with MSCs, we successfully regenerated a functional cranial suture that corrects skull deformity, normalizes intracranial pressure, and rescues neurocognitive behavior deficits. The regenerated suture creates a niche into which endogenous MSCs migrated, sustaining calvarial bone homeostasis and repair. MSC-based cranial suture regeneration offers a paradigm shift in treatment to reverse skull and neurocognitive abnormalities in this devastating disease.

The Sensitivity and Specificity of Parental Report of Concern for Identifying Language Disorder in Children With Craniosynostosis

ABSTRACT

Many factors that may co-occur with craniosynostosis, such as oral structural anomalies, hearing impairment, visual impairment, cognitive difficulties and psychosocial factors, may predispose this population to communication difficulties. At the Oxford Craniofacial Unit, children's speech, language and communication are regularly monitored in accordance with a systematic developmental screening protocol developed by the Speech and Language Therapists in the 4 United Kingdom (UK) Highly Specialized Craniofacial Centers. In addition to routine assessments, when parents attend routine multidisciplinary clinic appointments, they are asked about their child's communication development, and whether they have any concerns.A retrospective review was undertaken of parental concerns about hearing, speech development, behavior, physical development, concentration, school and friendships as indicated by parents on the Oxford Craniofacial Unit Pre-Clinic Questionnaire. The areas of concern were then correlated with the results of a standardized, guided parent questionnaire about children's language development, (Children's Communication Checklist - 2 (CCC-2)), to determine whether parental concern alone is a reliable way of identifying whether patients require further assessment for Language Disorder associated with Craniosynostosis.Participants were parents of 89 monolingual English-speaking children with craniosynostosis (62 male; 27 female), age range four to 13 years (mean age = 8 years 7 months), receiving active care at the Oxford Craniofacial Unit (June 2017-July 2018). Results of the pre-clinic questionnaire indicated that 6% of parents had concerns about their child's communication development. Results of the CCC-2 indicated that 29/89 (32.6%) of children required further assessment for Language Disorder associated with Craniosynostosis. When language difficulties were identified on the CCC-2, only 14% (n = 4/29) parents indicated concern on the pre clinic questionnaire. Results indicated that parental concern about behavior was the most important factor in identifying language disorder (P = 0.023).Results reinforce that the pre-clinic questionnaire is useful for identifying areas of parental concern. Results also indicate that parental concern alone is not sufficient to identify language disorder, and that further, detailed assessment is warranted. The results are consistent with previously reported links between behavior and language in the general population.