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Genes Dec 2023Nager syndrome is a rare human developmental disorder characterized by craniofacial defects including the downward slanting of the palpebral fissures, cleft palate, limb... (Review)
Review
Nager syndrome is a rare human developmental disorder characterized by craniofacial defects including the downward slanting of the palpebral fissures, cleft palate, limb deformities, mandibular hypoplasia, hypoplasia or absence of thumbs, microretrognathia, and ankylosis of the temporomandibular joint. The prevalence is very rare and the literature describes only about a hundred cases of Nager syndrome. There is evidence of autosomal dominant and autosomal recessive inheritance for Nager syndrome, suggesting genetic heterogeneity. The majority of the described causes of Nager syndrome include pathogenic variants in the gene, which encodes a component of the spliceosome; therefore, the syndrome belongs to the spliceosomopathy group of diseases. The diagnosis is made on the basis of physical and radiological examination and detection of mutations in the gene. Due to the diversity of defects associated with Nager syndrome, patients require multidisciplinary, complex, and long-lasting treatment. Usually, it starts from birth until the age of twenty years. The surgical procedures vary over a patient's lifetime and are related to the needed function. First, breathing and feeding must be facilitated; then, oral and facial clefts should be addressed, followed by correcting eyelid deformities and cheekbone reconstruction. In later age, a surgery of the nose and external ear is performed. Speech and hearing disorders require specialized logopedic treatment. A defect of the thumb is treated by transplanting a tendon and muscle or transferring the position of the index finger. In addition to surgery, in order to maximize a patient's benefit and to reduce functional insufficiency, complementary treatments such as rehabilitation and physiotherapy are recommended. In our study, we describe eight patients of different ages with various cases of Nager syndrome. The aim of our work was to present the actual genetic knowledge on this disease and its treatment procedures.
Topics: Child; Humans; Young Adult; Adult; Mandibulofacial Dysostosis; Cleft Palate; Micrognathism; Syndrome; RNA Splicing Factors
PubMed: 38254920
DOI: 10.3390/genes15010029 -
Bioscience Reports Jun 2013ORC (origin recognition complex) serves as the initiator for the assembly of the pre-RC (pre-replication complex) and the subsequent DNA replication. Together with many... (Review)
Review
ORC (origin recognition complex) serves as the initiator for the assembly of the pre-RC (pre-replication complex) and the subsequent DNA replication. Together with many of its non-replication functions, ORC is a pivotal regulator of various cellular processes. Notably, a number of reports connect ORC to numerous human diseases, including MGS (Meier-Gorlin syndrome), EBV (Epstein-Barr virus)-infected diseases, American trypanosomiasis and African trypanosomiasis. However, much of the underlying molecular mechanism remains unclear. In those genetic diseases, mutations in ORC alter its function and lead to the dysregulated phenotypes; whereas in some pathogen-induced symptoms, host ORC and archaeal-like ORC are exploited by these organisms to maintain their own genomes. In this review, I provide detailed examples of ORC-related human diseases, and summarize the current findings on how ORC is involved and/or dysregulated. I further discuss how these discoveries can be generalized as model systems, which can then be applied to elucidating other related diseases and revealing potential targets for developing effective therapies.
Topics: Animals; Congenital Microtia; DNA Replication; Ear; Epstein-Barr Virus Infections; Growth Disorders; Herpesvirus 4, Human; Host-Pathogen Interactions; Humans; Micrognathism; Mutation; Origin Recognition Complex; Patella; Trypanosoma; Trypanosomiasis
PubMed: 23662735
DOI: 10.1042/BSR20130036 -
Nature Communications Dec 2022The cohesin complex participates in many structural and functional aspects of genome organization. Cohesin recruitment onto chromosomes requires nucleosome-free DNA and...
The cohesin complex participates in many structural and functional aspects of genome organization. Cohesin recruitment onto chromosomes requires nucleosome-free DNA and the Scc2-Scc4 cohesin loader complex that catalyzes topological cohesin loading. Additionally, the cohesin loader facilitates promoter nucleosome clearance in a yet unknown way, and it recognizes chromatin receptors such as the RSC chromatin remodeler. Here, we explore the cohesin loader-RSC interaction. Amongst multi-pronged contacts by Scc2 and Scc4, we find that Scc4 contacts a conserved patch on the RSC ATPase motor module. The cohesin loader directly stimulates in vitro nucleosome sliding by RSC, providing an explanation how it facilitates promoter nucleosome clearance. Furthermore, we observe cohesin loader interactions with a wide range of chromatin remodelers. Our results provide mechanistic insight into how the cohesin loader recognizes, as well as influences, the chromatin landscape, with implications for our understanding of human developmental disorders including Cornelia de Lange and Coffin-Siris syndromes.
Topics: Humans; Chromatin; Saccharomyces cerevisiae Proteins; Cell Cycle Proteins; Nucleosomes; Chromosome Segregation; Micrognathism
PubMed: 36509793
DOI: 10.1038/s41467-022-35444-6 -
Italian Journal of Pediatrics Feb 2012The Pierre Robin Sequence features were first described by Robin in 1923 and include micrognathia, glossoptosis and respiratory distress with an incidence estimated as... (Review)
Review
BACKGROUND
The Pierre Robin Sequence features were first described by Robin in 1923 and include micrognathia, glossoptosis and respiratory distress with an incidence estimated as 1:8,500 to 1:20,000 newborns. Upper airway obstruction and feeding difficulties are the main concerns related to the pathology. Mandibular distraction should be considered a treatment option (when other treatments result inadequate). PATIANTS AND METHODS: Ten patients between the ages of 1 month and 2 years with severe micrognathia and airway obstruction were treated with Mandibular Distraction Osteogenesis (MDO).All patients underwent fibroscopic examination of the upper airway and a radiographic imaging and/or computed tomography scans to detect malformations and to confirm that the obstruction was caused by posterior tongue displacement. All patients were evaluated by a multidisciplinary team. Indications for surgery included frequent apneic episodes with severe desaturation (70%). Gavage therapy was employed in all patients since oral feeding was not possible. The two tracheotomy patients were 5 months and 2 years old respectively, and the distraction procedure was performed to remove the tracheotomy tube. All patients were treated with bilateral mandibular distraction: two cases with an external multivector distraction device, six cases with an internal non-resorbable device and two cases with an internal resorbable device. In one case, the patient with Goldenhar's Syndrome, the procedure was repeated.
RESULTS
The resolution of symptoms was obtained in all patients, and, when present, tracheotomy was removed without complications. Of the two patients with pre-existing tracheotomies, in the younger patient (5 months old) the tracheotomy was removed 7 days postoperatively. In the Goldenhar's syndrome case (2 years old) a Montgomery device was necessary for 6 months due to the presence of tracheotomy-inducted tracheomalacia. Patients were discharged when the endpoint was obtained: symptoms and signs of airway obstruction were resolved, PAS and maxillomandibular relationship improved, and tracheotomy, when present, removed. During the follow-up, no injury to the inferior alveolar nerve was noted and scarring was significant in only the two cases treated with external devices.
CONCLUSION
Mandibular Distraction Osteogenesis is a good solution in solving respiratory distress when other procedures are failed in paediatric patients with severe micrognatia.
Topics: Airway Obstruction; Child, Preschool; Female; Goldenhar Syndrome; Humans; Infant; Infant, Newborn; Male; Mandible; Micrognathism; Osteogenesis, Distraction; Pierre Robin Syndrome; Respiratory Distress Syndrome, Newborn; Treatment Outcome
PubMed: 22300418
DOI: 10.1186/1824-7288-38-7 -
Journal of Korean Medical Science Feb 2012Hereditary sclerosing poikiloderma (HSP) is a very rare disease. The clinical features are principally widespread poikiloderma and linear hyperkeratotic and sclerotic...
Hereditary sclerosing poikiloderma (HSP) is a very rare disease. The clinical features are principally widespread poikiloderma and linear hyperkeratotic and sclerotic bands. We report an 18-yr-old male who presented reticular hyperpigmented lesions on the trunk and extremities since 2-yr-old. Also, linear sclerosing bands appeared on both antecubital and popliteal fossae after yr. Histopathologic finding showed dense sclerotic collagen fibers with telangiectasia in the upper dermis and fragmentations of damaged elastic fibers in the elastic stain, consistent with HSP. We report the first Korean case of HSP.
Topics: Abnormalities, Multiple; Adolescent; Elastic Tissue; Fingers; Humans; Hyperpigmentation; Male; Micrognathism; Rothmund-Thomson Syndrome; Sclerosis; Skin Diseases
PubMed: 22323875
DOI: 10.3346/jkms.2012.27.2.225 -
BMJ Case Reports Jan 2021We report a child, diagnosed with Coffin-Siris syndrome (CSS), with chronic right otorrhoea. CT and DR-MRI were performed to further investigate, diagnose and determine...
We report a child, diagnosed with Coffin-Siris syndrome (CSS), with chronic right otorrhoea. CT and DR-MRI were performed to further investigate, diagnose and determine relevant surgical anatomy. CT temporal bones assessment was performed, and the measurements compared with previously published data for normal temporal bone anatomy. These comparisons highlighted various differences which were not initially expected; it showed that there were multiple inner ear abnormalities in addition to middle ear disease. This case highlights the importance of considering temporal bone abnormalities in all children with CSS or any dysmorphia, when they may require mastoid procedures. Reviewing the management of this case provides relevant learning opportunities for both primary, secondary and tertiary care institutions.
Topics: Abnormalities, Multiple; Bone Diseases, Developmental; Child; Face; Hand Deformities, Congenital; Humans; Intellectual Disability; Magnetic Resonance Imaging; Male; Micrognathism; Neck; Temporal Bone; Tomography, X-Ray Computed
PubMed: 33461995
DOI: 10.1136/bcr-2020-236139 -
Frontiers in Pediatrics 2023This study will list the most common comorbidities of congenital facial nerve palsy and how to detect and treat them, with special attention for ENT-problems such as...
OBJECTIVES
This study will list the most common comorbidities of congenital facial nerve palsy and how to detect and treat them, with special attention for ENT-problems such as hearing loss. Congenital facial nerve palsy is a very rare entity but in UZ Brussels hospital there was a follow-up of 16 children in the last 30 years.
METHODS
Literature review has been done, combined with thorough research of our own series of 16 children with congenital facial nerve palsy.
RESULTS
Congenital facial nerve palsy can be part of a known syndrome, most commonly Moebius syndrome, but can also appear solely. It appears often bilateral and with a severe gradation. In our series, hearing loss is frequently seen in association with congenital facial nerve palsy. Other abnormalities are dysfunction of the abducens nerve, ophthalmological problems, retro- or micrognathism and abnormalities of limbs or heart. The majority of the children in our series underwent radiological imaging (CT and/or MRI): the facial nerve but also the vestibulocochlear nerve and middle and inner ear can be evaluated.
CONCLUSION
A multidisciplinary approach of congenital facial nerve palsy is recommended as it can affect various bodily functions. Radiological imaging needs to be done to acquire additional information that can be useful for diagnostic and therapeutic purposes. Although congenital facial nerve palsy may not be treatable itself, its comorbidities can be treated and improve the quality of life of the affected child.
PubMed: 36891227
DOI: 10.3389/fped.2023.1077238 -
Pediatrics May 2011The triad of micrognathia, glossoptosis, and resultant airway obstruction is known as Robin sequence (RS). Although RS is a well-recognized clinical entity, there is... (Review)
Review
The triad of micrognathia, glossoptosis, and resultant airway obstruction is known as Robin sequence (RS). Although RS is a well-recognized clinical entity, there is wide variability in the diagnosis and care of children born with RS. Systematic evaluations of treatments and clinical outcomes for children with RS are lacking despite the advances in clinical care over the past 20 years. We explore the pathogenesis, developmental and genetic models, morphology, and syndromes and malformations associated with RS. Current classification systems for RS do not account for the heterogeneity among infants with RS, and they do not allow for prediction of the optimal management course for an individual child. Although upper airway obstruction for some infants with RS can be treated adequately with positioning, other children may require a tracheostomy. Care must be customized for each patient with RS, and health care providers must understand the anatomy and mechanism of airway obstruction to develop an individualized treatment plan to improve breathing and achieve optimal growth and development. In this article we provide a comprehensive overview of evaluation strategies and therapeutic options for children born with RS. We also propose a conceptual treatment protocol to guide the provider who is caring for a child with RS.
Topics: Airway Obstruction; Case Management; Child Development; Child, Preschool; Combined Modality Therapy; Female; Humans; Infant; Infant, Newborn; Male; Micrognathism; Oral Surgical Procedures; Patient Care Team; Pierre Robin Syndrome; Prognosis; Risk Assessment; Tongue Diseases; Tracheotomy; Treatment Outcome
PubMed: 21464188
DOI: 10.1542/peds.2010-2615 -
International Journal of Oral Science Oct 2022Micrognathia is a severe craniofacial deformity affecting appearance and survival. Previous studies revealed that multiple factors involved in the osteogenesis of...
Micrognathia is a severe craniofacial deformity affecting appearance and survival. Previous studies revealed that multiple factors involved in the osteogenesis of mandibular bone have contributed to micrognathia, but concerned little on factors other than osteogenesis. In the current study, we found that ectopic activation of Fgf8 by Osr2-cre in the presumptive mesenchyme for masseter tendon in mice led to micrognathia, masseter regression, and the disrupted patterning and differentiation of masseter tendon. Since Myf5-cre;Rosa26R-Fgf8 mice exhibited the normal masseter and mandibular bone, the possibility that the micrognathia and masseter regression resulted directly from the over-expressed Fgf8 was excluded. Further investigation disclosed that a series of chondrogenic markers were ectopically activated in the developing Osr2-cre;Rosa26R-Fgf8 masseter tendon, while the mechanical sensing in the masseter and mandibular bone was obviously reduced. Thus, it suggested that the micrognathia in Osr2-cre;Rosa26R-Fgf8 mice resulted secondarily from the reduced mechanical force transmitted to mandibular bone. Consistently, when tenogenic or myogenic components were deleted from the developing mandibles, both the micrognathia and masseter degeneration took place with the decreased mechanical sensing in mandibular bone, which verified that the loss of mechanical force transmitted by masseter tendon could result in micrognathia. Furthermore, it appeared that the micrognathia resulting from the disrupted tenogenesis was attributed to the impaired osteogenic specification, instead of the differentiation in the periosteal progenitors. Our findings disclose a novel mechanism for mandibular morphogenesis, and shed light on the prevention and treatment for micrognathia.
Topics: Mice; Animals; Micrognathism; Masseter Muscle; Mandible; Osteogenesis
PubMed: 36257937
DOI: 10.1038/s41368-022-00196-y -
JCI Insight May 2022The eukaryotic CDC45/MCM2-7/GINS (CMG) helicase unwinds the DNA double helix during DNA replication. The GINS subcomplex is required for helicase activity and is,...
The eukaryotic CDC45/MCM2-7/GINS (CMG) helicase unwinds the DNA double helix during DNA replication. The GINS subcomplex is required for helicase activity and is, therefore, essential for DNA replication and cell viability. Here, we report the identification of 7 individuals from 5 unrelated families presenting with a Meier-Gorlin syndrome-like (MGS-like) phenotype associated with hypomorphic variants of GINS3, a gene not previously associated with this syndrome. We found that MGS-associated GINS3 variants affecting aspartic acid 24 (D24) compromised cell proliferation and caused accumulation of cells in S phase. These variants shortened the protein half-life, altered key protein interactions at the replisome, and negatively influenced DNA replication fork progression. Yeast expressing MGS-associated variants of PSF3 (the yeast GINS3 ortholog) also displayed impaired growth, S phase progression defects, and decreased Psf3 protein stability. We further showed that mouse embryos homozygous for a D24 variant presented intrauterine growth retardation and did not survive to birth, and that fibroblasts derived from these embryos displayed accelerated cellular senescence. Taken together, our findings implicate GINS3 in the pathogenesis of MGS and support the notion that hypomorphic variants identified in this gene impaired cell and organismal growth by compromising DNA replication.
Topics: Animals; Chromosomal Proteins, Non-Histone; Congenital Microtia; DNA Replication; Growth Disorders; Humans; Mice; Micrognathism; Minichromosome Maintenance Proteins; Patella; Saccharomyces cerevisiae
PubMed: 35603789
DOI: 10.1172/jci.insight.155648