Search Results (4)

Background: Facial features are the first basic sign of medical knowledge of children and adults with congenital malformations. Children born with multiple contractures almost always receive the misdiagnosis of arthrogryposis multiplex. Larsen syndrome can easily be diagnosed at birth via the proper interpretations of its characteristic facial features and multiple dislocations. Comprehensive clinical diagnosis can facilitate an orthopedic strategy for early treatment and can enhance the recognition of unreported craniocervical malformation complexes. Material and Methods: Six children (four boys and two girls, with ages ranging from a few months to 7 years old) were referred to our department for diagnosis and treatment. All children received their first misdiagnosis by the pediatricians as manifesting arthrogryposis multiplex congenita. The clinical phenotype was our first decisive tool for diagnosis. All children exhibited the classical phenotype of dish-like facies associated with multiple joint dislocations. Radiological phenotypic characteristics confirmed our clinical diagnosis of Larsen syndrome. Three children out of six showed unpleasant cervical spine deformities. The first child, a 2-year-old, became tetraplegic after minor trauma. One child presented with progressive rigid cervical kyphosis. The third child was a product of a first-relative marriage and was born with congenital tetraplegia. A genotype was carried out for confirmation. Results: Three children underwent open reduction for congenital hip and knee dislocations. One child underwent spinal fusion CO-C7 because of tetraplegia. A 3D-reformatted and reconstruction CT scan of the craniocervical junction showed two forms of unusual dys-segmentation, firstly along C2-3 effectively causing the development of acute-angle cervical kyphosis. Secondly, an infant with congenital tetraplegia showed a serious previously undescribed atlanto–axial malformation complex. Namely, atlanto–axial maldevelopment (dys-segmentation) of (C1/C2) was associated with hypoplasia of the anterior and the posterior rings of the atlas. Genetic tests of these children were compatible with the autosomal dominant type of Larsen syndrome and manifested a heterozygous mutation in FLNB mapped 3p14.3, encoding an actin-binding protein, filamin B. The child with congenital tetraplegia showed no mutations in FLNB, though his clinical and radiological phenotype and his family history of first-relative marriage were totally compatible with the diagnosis of the autosomal recessive type of Larsen syndrome. Conclusions: Our strategy was and still is based on a coherent clinical and radiological diagnosis, which is based on comprehensive clinical and radiological phenotypic characterizations. We implemented a 3D-reformatted CT scan to further understand the craniocervical junction pathology in three children. Strikingly, prenatal onset of lethal maldevelopment (dys-segmentation) of the atlanto–axial spine segments has been diagnosed in an infant with congenital tetraplagia. A less serious cervical spine malformation was detected in two children who presented with progressive acute-angle cervico and cervico-thoracic kyphosis. Our clinical strategy can form the basis for a thorough clinical assessment for infants and children born with multiple malformation complexes and can lead to recognition of novel understandings. Full article

Osteochondrosis and apophysitis are common causes of pain in the growing skeleton, each with different causes and treatment approaches. Osteochondrosis involves degenerative processes affecting the epiphyseal ossification centers of the developing bones, while apophysitis results from repetitive traction injuries to the tendon insertions and affects both the cartilage and the underlying bone. Raising awareness of these conditions is crucial to facilitate the recovery of young athletes and prevent their sporting careers from being jeopardized early on. This review presents six known lower limb conditions that occur in young athletes, including three apophysitis such as Osgood–Schlatter disease, Sinding–Larsen–Johansson syndrome, and Sever’s disease, and three osteochondroses, including Perthes’ disease, Köhler’s disease, and Freiberg’s disease. The aim of this review is to outline the pathophysiology, clinical presentation, and treatment strategies for each of these conditions to provide a comprehensive understanding of their impact on young athletes. This review will provide clinicians, coaches, and physiotherapists with essential, evidence-based insights to increase their awareness of these conditions and refine treatment strategies for young athletes. Full article

Filamins (FLN) are a family of actin-binding proteins involved in regulating the cytoskeleton and signaling phenomenon by developing a network with F-actin and FLN-binding partners. The FLN family comprises three conserved isoforms in mammals: FLNA, FLNB, and FLNC. FLNB is a multidomain monomer protein with domains containing an actin-binding N-terminal domain (ABD 1–242), encompassing two calponin-homology domains (assigned CH1 and CH2). Primary variants in FLNB mostly occur in the domain (CH2) and surrounding the hinge-1 region. The four autosomal dominant disorders that are associated with FLNB variants are Larsen syndrome, atelosteogenesis type I (AOI), atelosteogenesis type III (AOIII), and boomerang dysplasia (BD). Despite the intense clustering of FLNB variants contributing to the LS-AO-BD disorders, the genotype-phenotype correlation is still enigmatic. In silico prediction tools and molecular dynamics simulation (MDS) approaches have offered the potential for variant classification and pathogenicity predictions. We retrieved 285 FLNB missense variants from the UniProt, ClinVar, and HGMD databases in the current study. Of these, five and 39 variants were located in the CH1 and CH2 domains, respectively. These variants were subjected to various pathogenicity and stability prediction tools, evolutionary and conservation analyses, and biophysical and physicochemical properties analyses. Molecular dynamics simulation (MDS) was performed on the three candidate variants in the CH2 domain (W148R, F161C, and L171R) that were predicted to be the most pathogenic. The MDS analysis results showed that these three variants are highly compact compared to the native protein, suggesting that they could affect the protein on the structural and functional levels. The computational approach demonstrates the differences between the FLNB mutants and the wild type in a structural and functional context. Our findings expand our knowledge on the genotype-phenotype correlation in FLNB-related LS-AO-BD disorders on the molecular level, which may pave the way for optimizing drug therapy by integrating precision medicine. Full article

The term linkeropathies (LKs) refers to a group of rare heritable connective tissue disorders, characterized by a variable degree of short stature, skeletal dysplasia, joint laxity, cutaneous anomalies, dysmorphism, heart malformation, and developmental delay. The LK genes encode for enzymes that add glycosaminoglycan chains onto proteoglycans via a common tetrasaccharide linker region. Biallelic variants in XYLT1 and XYLT2, encoding xylosyltransferases, are associated with Desbuquois dysplasia type 2 and spondylo-ocular syndrome, respectively. Defects in B4GALT7 and B3GALT6, encoding galactosyltransferases, lead to spondylodysplastic Ehlers-Danlos syndrome (spEDS). Mutations in B3GAT3, encoding a glucuronyltransferase, were described in 25 patients from 12 families with variable phenotypes resembling Larsen, Antley-Bixler, Shprintzen-Goldberg, and Geroderma osteodysplastica syndromes. Herein, we report on a 13-year-old girl with a clinical presentation suggestive of spEDS, according to the 2017 EDS nosology, in whom compound heterozygosity for two B3GAT3 likely pathogenic variants was identified. We review the spectrum of B3GAT3-related disorders and provide a comparison of all LK patients reported up to now, highlighting that LKs are a phenotypic continuum bridging EDS and skeletal disorders, hence offering future nosologic perspectives. Full article