-
Developmental Dynamics : An Official... Oct 2022Major cell-to-cell signaling pathways, such as the fibroblast growth factors and their four receptors (FGF/FGFR), are conserved across a variety of animal forms....
BACKGROUND
Major cell-to-cell signaling pathways, such as the fibroblast growth factors and their four receptors (FGF/FGFR), are conserved across a variety of animal forms. FGF/FGFRs are necessary to produce several "vertebrate-specific" structures, including the vertebrate head. Here, we examine the effects of the FGFR2 S252W mutation associated with Apert syndrome on patterns of cranial integration. Our data comprise micro-computed tomography images of newborn mouse skulls, bred to express the Fgfr2 S252W mutation exclusively in either neural crest or mesoderm-derived tissues, and mice that express the Fgfr2 S252W mutation ubiquitously.
RESULTS
Procrustes-based methods and partial least squares analysis were used to analyze craniofacial integration patterns. We found that deviations in the direction and degree of integrated shape change across the mouse models used in our study were potentially driven by the modular variation generated by differing expression of the Fgfr2 mutation in cranial tissues.
CONCLUSIONS
Our overall results demonstrate that covariation patterns can be biased by the spatial distribution and magnitude of variation produced by underlying developmental-genetic mechanisms that often impact the phenotype in disproportionate ways.
Topics: Acrocephalosyndactylia; Animals; Disease Models, Animal; Fibroblast Growth Factors; Mice; Mutation; Receptor, Fibroblast Growth Factor, Type 2; Skull; X-Ray Microtomography
PubMed: 35582939
DOI: 10.1002/dvdy.498 -
Genes Jun 2022Craniosynostosis are a heterogeneous group of genetic conditions characterized by the premature fusion of the skull bones. The most common forms of craniosynostosis are...
Craniosynostosis are a heterogeneous group of genetic conditions characterized by the premature fusion of the skull bones. The most common forms of craniosynostosis are Crouzon, Apert and Pfeiffer syndromes. They differ from each other in various additional clinical manifestations, e.g., syndactyly is typical of Apert and rare in Pfeiffer syndrome. Their inheritance is autosomal dominant with incomplete penetrance and one of the main genes responsible for these syndromes is FGFR2, mapped on chromosome 10, encoding fibroblast growth factor receptor 2. We report an FGFR2 gene variant in a mother and daughter who present with different clinical features of Crouzon syndrome. The daughter is more severely affected than her mother, as also verified by a careful study of the face and oral cavity. The c.1032G>A transition in exon 8, already reported as a synonymous p.Ala344 = variant in Crouzon patients, also activates a new donor splice site leading to the loss of 51 nucleotides and the in-frame removal of 17 amino acids. We observed lower FGFR2 transcriptional and translational levels in the daughter compared to the mother and healthy controls. A preliminary functional assay and a molecular modeling added further details to explain the discordant phenotype of the two patients.
Topics: Acrocephalosyndactylia; Craniosynostoses; Female; Humans; Mothers; Phenotype; Receptor, Fibroblast Growth Factor, Type 2
PubMed: 35885943
DOI: 10.3390/genes13071161 -
Clinical Oral Investigations Jul 2019To determine whether the intramaxillary relationship of patients with Muenke syndrome and Saethre-Chotzen syndrome or TCF12-related craniosynostosis are systematically...
OBJECTIVES
To determine whether the intramaxillary relationship of patients with Muenke syndrome and Saethre-Chotzen syndrome or TCF12-related craniosynostosis are systematically different than those of a control group.
MATERIAL AND METHODS
Forty-eight patients (34 patients with Muenke syndrome, 8 patients with Saethre-Chotzen syndrome, and 6 patients with TCF12-related craniosynostosis) born between 1982 and 2010 (age range 4.84 to 16.83 years) that were treated at the Department of Oral Maxillofacial Surgery, Special Dental Care and Orthodontics, Children's Hospital Erasmus University Medical Center, Sophia, Rotterdam, the Netherlands, were included. Forty-seven syndromic patients had undergone one craniofacial surgery according to the craniofacial team protocol. The dental arch measurements intercanine width (ICW), intermolar width (IMW), arch depth (AD), and arch length (AL) were calculated. The control group existed of 329 nonsyndromic children.
RESULTS
All dental arch dimensions in Muenke (ICW, IMW, AL, p < 0.001, ADmax, p = 0.008; ADman, p = 0.002), Saethre-Chotzen syndrome, or TCF12-related craniosynostosis patients (ICWmax, p = 0.005; ICWman, IMWmax, AL, p < 0.001) were statistically significantly smaller than those of the control group.
CONCLUSIONS
In this study, we showed that the dental arches of the maxilla and the mandible of patients with Muenke syndrome and Saethre-Chotzen syndrome or TCF12-related craniosynostosis are smaller compared to those of a control group.
CLINICAL RELEVANCE
To gain better understanding of the sutural involvement in the midface and support treatment capabilities of medical and dental specialists in these patients, we suggest the concentration of patients with Muenke and Saethre-Chotzen syndromes or TCF12-related craniosynostosis in specialized teams for a multi-disciplinary approach and treatment.
Topics: Acrocephalosyndactylia; Adolescent; Child; Child, Preschool; Craniosynostoses; Dental Arch; Female; Humans; Male; Netherlands; Syndrome
PubMed: 30392078
DOI: 10.1007/s00784-018-2710-9 -
European Journal of Orthodontics May 2022To determine whether dental maturity (dental development) was delayed in patients with 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.
Topics: Acrocephalosyndactylia; Basic Helix-Loop-Helix Transcription Factors; Child; Child, Preschool; Craniosynostoses; Humans; Netherlands; Syndrome
PubMed: 34424951
DOI: 10.1093/ejo/cjab056 -
Journal of Medical Systems Jul 2020This paper presents a methodological procedure, based on the anatomical reconstruction and constrained deformation, to design custom-made implants for forehead...
This paper presents a methodological procedure, based on the anatomical reconstruction and constrained deformation, to design custom-made implants for forehead augmentation in people affected by Apert syndrome, experiencing a frontal bone deficiency. According to the anthropometric theory, a cranial landmarks identification procedure was applied to retrieve, from a repository, a healthy skull, used as reference geometry for implant modelling. Then, using constrained deformation and free-form modelling techniques, it was possible to design a patient-specific implant. At last, the implant was realised using a custom mould, specially designed according to the patient's needs to provide an accurate fit of the defect site. The design procedure was tested on a patient suffering from Apert syndrome. Three implants were virtually modelled and 3D-printed for pre-surgical evaluation. Their shapes were 3D compared with a reference one (handcrafted by a surgeon) to test the accuracy. Deviations are negligible, and the customised implant fulfilled the surgeon's requirements.
Topics: Acrocephalosyndactylia; Computer-Aided Design; Forehead; Humans; Imaging, Three-Dimensional; Plastic Surgery Procedures; Tomography, X-Ray Computed
PubMed: 32720066
DOI: 10.1007/s10916-020-01611-9 -
Scientific Reports Apr 2021Midface hypoplasia is a major manifestation of Apert syndrome. However, the tissue component responsible for midface hypoplasia has not been elucidated. We studied mice...
Midface hypoplasia is a major manifestation of Apert syndrome. However, the tissue component responsible for midface hypoplasia has not been elucidated. We studied mice with a chondrocyte-specific Fgfr2 mutation (Col2a1-cre; Fgfr2) to investigate the effect of cartilaginous components in midface hypoplasia of Apert syndrome. In Col2a1-cre; Fgfr2 mice, skull shape was normal at birth, but hypoplastic phenotypes became evident with age. General dimensional changes of mutant mice were comparable with those of mice with mutations in EIIa-cre; Fgfr2, a classic model of Apert syndrome in mice. Col2a1-cre; Fgfr2 mice showed some unique facial phenotypes, such as elevated nasion, abnormal fusion of the suture between the premaxilla and the vomer, and decreased perpendicular plate of the ethmoid bone volume, which are related to the development of the nasal septal cartilage. Morphological and histological examination revealed that the presence of increased septal chondrocyte hypertrophy and abnormal thickening of nasal septum is causally related to midface deformities in nasal septum-associated structures. Our results suggest that careful examination and surgical correction of the nasal septal cartilage may improve the prognosis in the surgical treatment of midface hypoplasia and respiratory problems in patients with Apert syndrome.
Topics: Acrocephalosyndactylia; Animals; Chondrocytes; Collagen Type II; Cranial Sutures; Disease Models, Animal; Face; Hypertrophy; Mice; Mutation; Nasal Septum; Receptor, Fibroblast Growth Factor, Type 2; X-Ray Microtomography
PubMed: 33846505
DOI: 10.1038/s41598-021-87260-5 -
The Journal of Hand Surgery, European... May 2024This study evaluated how Apert hand syndactyly presentations and reconstructive techniques influence reconstruction outcomes. All cases at a major paediatric hospital...
UNLABELLED
This study evaluated how Apert hand syndactyly presentations and reconstructive techniques influence reconstruction outcomes. All cases at a major paediatric hospital between 2007 and 2022 were analysed, including 98 web space reconstructions in 17 patients. Overall, 62% of hands developed complications and 15% required revision surgery. Upton hand type was significantly associated with postoperative complication incidence, specifically including range-of-motion deficits, flexion contracture, web creep and revision surgery. More severe syndactylies may benefit from additional measures to reduce complications. Rectangular commissural flaps showed 1.9 times greater complication risk than interdigitating triangular flaps, including 11.2 times greater risk of web creep. Zigzag volar finger flaps showed 1.8 times greater complication risk than straight-line incisions, including 3.8 times greater risk of web creep. Our study showed that interdigitating triangular commissural flaps and straight-line volar finger incisions are preferable to rectangular commissural and zigzag finger flaps in most cases of Apert hand syndactyly to minimize complications.
LEVEL OF EVIDENCE
III.
Topics: Humans; Male; Female; Postoperative Complications; Surgical Flaps; Risk Factors; Infant; Plastic Surgery Procedures; Acrocephalosyndactylia; Child, Preschool; Reoperation; Retrospective Studies; Syndactyly; Child; Range of Motion, Articular
PubMed: 37987676
DOI: 10.1177/17531934231213516 -
Journal of Medical Genetics Jun 2021Pathogenic DNA variants in the GLI-Kruppel family member 3 ( gene are known to cause multiple syndromes: for example, Greig syndrome, preaxial polydactyly-type 4 (PPD4)...
INTRODUCTION
Pathogenic DNA variants in the GLI-Kruppel family member 3 ( gene are known to cause multiple syndromes: for example, Greig syndrome, preaxial polydactyly-type 4 (PPD4) and Pallister-Hall syndrome. Out of these, Pallister-Hall is a different entity, but the distinction between Greig syndrome and PPD4 is less evident. Using latent class analysis (LCA), our study aimed to investigate the correlation between reported limb anomalies and the reported variants in these GLI3-mediated polydactyly syndromes. We identified two subclasses of limb anomalies that relate to the underlying variant.
METHODS
Both local and published cases were included for analysis. The presence of individual limb phenotypes was dichotomised and an exploratory LCA was performed. Distribution of phenotypes and genotypes over the classes were explored and subsequently the key predictors of latent class membership were correlated to the different clustered genotypes.
RESULTS
297 cases were identified with 127 different variants in the gene. A two-class model was fitted revealing two subgroups of patients with anterior versus posterior anomalies. Posterior anomalies were observed in cases with truncating variants in the activator domain (postaxial polydactyly; hand, OR: 12.7; foot, OR: 33.9). Multivariate analysis supports these results (Beta: 1.467, p=0.013 and Beta: 2.548, p<0.001, respectively). Corpus callosum agenesis was significantly correlated to these variants (OR: 8.8, p<0.001).
CONCLUSION
There are two distinct phenotypes within the GLI3-mediated polydactyly population: anteriorly and posteriorly orientated. Variants that likely produce haploinsufficiency are associated with anterior phenotypes. Posterior phenotypes are associated with truncating variants in the activator domain. Patients with these truncating variants have a greater risk for corpus callosum anomalies.
Topics: Acrocephalosyndactylia; Genetic Association Studies; Genetic Variation; Humans; Latent Class Analysis; Limb Deformities, Congenital; Nerve Tissue Proteins; Polydactyly; Syndrome; Zinc Finger Protein Gli3
PubMed: 32591344
DOI: 10.1136/jmedgenet-2020-106948 -
The Application of Clinical Genetics 2020Pfeiffer syndrome (PS) is an autosomal dominant disorder caused by mutations in fibroblast growth factor receptor FGFR1 and FGFR2 genes, occurring in approximately...
BACKGROUND
Pfeiffer syndrome (PS) is an autosomal dominant disorder caused by mutations in fibroblast growth factor receptor FGFR1 and FGFR2 genes, occurring in approximately 1:100,000 live births. PS has a wide range of clinical expression and severity, so early prenatal diagnosis is difficult and genetic counseling is desirable. We describe a PS newborn with her ultrasound and molecular studies.
CASE REPORT
We describe a female term newborn with cloverleaf-shaped skull, facial hypoplasia, low ears, exophthalmos and wide, broad and deviated thumbs and hallux. The patient was diagnosed by ultrasound at 29 WGA and referred to a tertiary care hospital for her follow-up. Molecular test revealed a heterozygous pathogenic variant in intron 8 of the FGFR2 gene (FGFR2: c.940-1G>C). It was a de-novo mutation. At 17 days of life, craniosynostosis correction and a Lefort-III frontomaxillary advancement were performed.
CONCLUSION
Pfeiffer syndrome is a devastating genetic disorder. Prenatal diagnosis according PS morphological features in prenatal ultrasound allows timely genetic counseling, early referral to third-level centers, and close follow-up in the prenatal and postnatal stages.
PubMed: 32848441
DOI: 10.2147/TACG.S251581 -
Stem Cell Research & Therapy Dec 2020During development, excessive osteogenic differentiation of mesenchymal progenitor cells (MPC) within the cranial sutures can lead to premature suture fusion or...
BACKGROUND
During development, excessive osteogenic differentiation of mesenchymal progenitor cells (MPC) within the cranial sutures can lead to premature suture fusion or craniosynostosis, leading to craniofacial and cognitive issues. Saethre-Chotzen syndrome (SCS) is a common form of craniosynostosis, caused by TWIST-1 gene mutations. Currently, the only treatment option for craniosynostosis involves multiple invasive cranial surgeries, which can lead to serious complications.
METHODS
The present study utilized Twist-1 haploinsufficient (Twist-1) mice as SCS mouse model to investigate the inhibition of Kdm6a and Kdm6b activity using the pharmacological inhibitor, GSK-J4, on calvarial cell osteogenic potential.
RESULTS
This study showed that the histone methyltransferase EZH2, an osteogenesis inhibitor, is downregulated in calvarial cells derived from Twist-1 mice, whereas the counter histone demethylases, Kdm6a and Kdm6b, known promoters of osteogenesis, were upregulated. In vitro studies confirmed that siRNA-mediated inhibition of Kdm6a and Kdm6b expression suppressed osteogenic differentiation of Twist-1 calvarial cells. Moreover, pharmacological targeting of Kdm6a and Kdm6b activity, with the inhibitor, GSK-J4, caused a dose-dependent suppression of osteogenic differentiation by Twist-1 calvarial cells in vitro and reduced mineralized bone formation in Twist-1 calvarial explant cultures. Chromatin immunoprecipitation and Western blot analyses found that GSK-J4 treatment elevated the levels of the Kdm6a and Kdm6b epigenetic target, the repressive mark of tri-methylated lysine 27 on histone 3, on osteogenic genes leading to repression of Runx2 and Alkaline Phosphatase expression. Pre-clinical in vivo studies showed that local administration of GSK-J4 to the calvaria of Twist-1 mice prevented premature suture fusion and kept the sutures open up to postnatal day 20.
CONCLUSION
The inhibition of Kdm6a and Kdm6b activity by GSK-J4 could be used as a potential non-invasive therapeutic strategy for preventing craniosynostosis in children with SCS. Pharmacological targeting of Kdm6a/b activity can alleviate craniosynostosis in Saethre-Chotzen syndrome. Aberrant osteogenesis by Twist-1 mutant cranial suture mesenchymal progenitor cells occurs via deregulation of epigenetic modifiers Ezh2 and Kdm6a/Kdm6b. Suppression of Kdm6a- and Kdm6b-mediated osteogenesis with GSK-J4 inhibitor can prevent prefusion of cranial sutures.
Topics: Acrocephalosyndactylia; Animals; Histone Demethylases; Jumonji Domain-Containing Histone Demethylases; Mice; Molecular Targeted Therapy; Nuclear Proteins; Osteogenesis; Twist-Related Protein 1
PubMed: 33298158
DOI: 10.1186/s13287-020-02051-5