Osteogenesis Imperfecta Disease Research Articles

Project SATURN– a real-world evidence data collaboration with existing European datasets in Osteogenesis Imperfecta to support future therapies

Regulatory marketing authorisation is not enough to ensure patient access to new medicinal products. Health Technology Assessment bodies may require data on effectiveness, relative effectiveness, and cost-effectiveness. Healthcare systems may require data on clinical utility, savings, and budget impact. Furthermore, the exact requirements of these bodies vary country by country and sometimes even region to region, resulting in a patchwork of different data requirements to achieve effective, reimbursed patient access to new therapies. In addition, clinicians require data to make informed clinical management decisions. This requirement is of key importance in rare diseases where there is often limited data and clinical experience at the time of regulatory approval.This paper describes an innovative initiative that is called Project SATURN: Systematic Accumulation of Treatment practices and Utilization, Real world evidence, and Natural history data for the rare disease Osteogenesis Imperfecta. The objective of this project is to generate a common core dataset by utilising existing data sources to meet the needs of the various stakeholders and avoiding fragmentation through multiple approaches (e.g., a series of individual national requests/approaches, and unconnected with the regulators’ potential requirements). It is expected that such an approach will reduce the time for patient access to life-changing medications. Whilst Project SATURN applies to Osteogenesis Imperfecta, it is anticipated that the principles could also be applied to other rare diseases and reduce the time for patient access to new medications.

The effect of carbamazepine on bone structure and strength in control and osteogenesis imperfecta (Col1a2+/p.G610C) mice

The inherited brittle bone disease osteogenesis imperfecta (OI) is commonly caused by COL1A1 and COL1A2 mutations that disrupt the collagen I triple helix. This causes intracellular endoplasmic reticulum (ER) retention of the misfolded collagen and can result in a pathological ER stress response. A therapeutic approach to reduce this toxic mutant load could be to stimulate mutant collagen degradation by manipulating autophagy and/or ER‐associated degradation. Since carbamazepine (CBZ) both stimulates autophagy of misfolded collagen X and improves skeletal pathology in a metaphyseal chondrodysplasia model, we tested the effect of CBZ on bone structure and strength in 3‐week‐old male OI Col1a2 +/p.G610C and control mice. Treatment for 3 or 6 weeks with CBZ, at the dose effective in metaphyseal chondrodysplasia, provided no therapeutic benefit to Col1a2 +/p.G610C mouse bone structure, strength or composition, measured by micro‐computed tomography, three point bending tests and Fourier‐transform infrared microspectroscopy. In control mice, however, CBZ treatment for 6 weeks impaired femur growth and led to lower femoral cortical and trabecular bone mass. These data, showing the negative impact of CBZ treatment on the developing mouse bones, raise important issues which must be considered in any human clinical applications of CBZ in growing individuals.

Quantitative gait analysis in children with osteogenesis imperfecta: relationship between gait deviations and clinical features.

Osteogenesis imperfecta is a rare congenital disease of connective tissue characterized by recurrent fractures and progressive skeletal deformities which may impact on gait. The aims of this prospective study were to identify gait deviations in children with osteogenesis imperfecta compared to age-matched controls and establish relationships with clinical features. We evaluated 22 patients with different types of osteogenesis imperfecta using three-dimensional gait analysis. The incidence and location of frac- tures, fracture at birth, age at first fracture, use of intramedullary rodding and number of surgical in- terventions in the lower extremities, bone mineral density, hypermobility and number of injections of bisphosphonates were recorded for each patient. Step length was lower in the osteogenesis imperfecta group compared with the control group. Kinematics showed that sagittal pelvic and transversal hip range of motion were higher in the osteogenesis imperfecta group, whereas sagittal knee range of motion during swing phase was reduced. Regarding kinetics, hip flexion moment and hip negative power peak were significantly decreased in the osteogenesis imperfecta group. Mechanical and energetic parameters were considered as normal. The principal component analysis revealed that the bone mineral density was increased in children who had received more in- jections of bisphosphonates and these had also less deficit in kinematic parameters. Main modifications in gait parameters were observed in spatiotemporal, kinematic and kinetic data. More studies are necessary to allow stratification of severity of the osteogenesis imperfecta disease, help improve its challenging multidisciplinary treatment and ob- jectively assess treatment outcomes.

Genetic Analysis and Functional Study of a Pedigree With Bruck Syndrome Caused by PLOD2 Variant.

BackgroundBruck syndrome (BS) is a rare autosomal recessive inherited osteogenesis imperfecta disease characterized by increased bone fragility and joint contracture. The pathogenic gene of type I BS is FKBPl0, whereas that of type II BS is PLOD2. No significant difference has been found in the clinical phenotype between the two types of BS. In this study, we performed genetic analysis of a BS pedigree caused by PLOD2 variant and studied the corresponding cellular function.MethodsSerum biochemistry, parathyroid hormone (PTH), 25-hydroxyvitamin D [25-(OH) D], osteocalcin, and 24-h urinary calcium levels of a family member with BS was assessed. The genes of the proband were analyzed by second-generation sequencing and exon capture techniques. Sanger sequencing was also performed for the suspected responsible variant of the family member. Wild- and variant-type lentivirus plasmids were constructed by gene cloning and transfected into HEK293T cells. Cell function was verified by real-time quantitative polymerase chain reaction, western blotting, and immunofluorescence detection.ResultsIn this pedigree, the proband was found to have a homozygous variant c.1856G > A (p.Arg619His) in exon 17 of PLOD2 (NM_182943.3). His consanguineous parents and sisters were p.Arg619His heterozygous carriers. The mRNA expression of PLOD2 in the constructed p.Arg619His variant cells was significantly upregulated, while the expression of PLOD2 and collagen I protein in the cell lysate was significantly downregulated. Immunofluorescence revealed that the wild-type PLOD2 was mainly located in the cytoplasm, and the expression of the PLOD2 protein after c.1856G > A variant was significantly downregulated, with almost no expression, aligning with the western blot results. The serum sodium, potassium, calcium, phosphorus, magnesium, alkaline phosphatase, PTH, 25-(OH) D, osteocalcin, and 24 h urinary calcium levels of the proband, his parents, and sisters were normal.ConclusionThrough gene and cell function analyses, PLOD2 Arg619His missense variant was preliminarily confirmed to cause BS by reducing protein expression.

Infrared Spectroscopy-Determined Bone Compositional Changes Associated with Anti-Resorptive Treatment of the oim/oim Mouse Model of Osteogenesis Imperfecta.

Applications of vibrational spectroscopy to assess bone disease and therapeutic interventions are continually advancing, with tissue mineral and protein composition frequently investigated. Here, we used two spectroscopic approaches for determining bone composition in a mouse model (oim) of the brittle bone disease osteogenesis imperfecta (OI) with and without antiresorptive agent treatment (alendronate, or ALN, and RANK-Fc). Near-infrared (NIR) spectral analysis using a fiber optic probe and attenuated total reflection Fourier transform infrared spectroscopy (ATR FTIR) mode were applied to investigate bone composition, including water, mineral, and protein content. Spectral parameters revealed differences among the control wildtype (WT) and OIM groups. NIR spectral analysis of protein and water showed that OIM mouse humerii had ∼50% lower protein and ∼50% higher overall water content compared to WT bone. Moreover, some OIM-treated groups showed a reduction in bone water compared to OIM controls, approximating values observed in WT bone. Differences in bone quality based on increased mineral content and reduced carbonate content were also found between some groups of treated OIM and WT bone, but crystallinity did not differ among all groups. The spectroscopically determined parameters were evaluated for correlations with gold-standard mechanical testing values to gain insight into how composition influenced bone strength. As expected, bone mechanical strength parameters were consistently up to threefold greater in WT mice compared to OIM groups, except for stiffness in the ALN-treated OIM groups. Furthermore, bone stiffness, maximum load, and post-yield displacement showed the strongest correlations with NIR-determined protein content (positive correlations) and bound-water content (negative correlations). These results demonstrate that in this study, NIR spectral parameters were more sensitive to bone composition differences than ATR parameters, highlighting the potential of this nondestructive approach for screening of bone diseases and therapeutic efficacy in pre-clinical models.

Cytoplasmic polyadenylation by TENT5A is required for proper bone formation.

Osteoblasts orchestrate bone formation through the secretion of type I collagen and other constituents of the matrix on which hydroxyapatite crystals mineralize. Here, we show that TENT5A, whose mutations were found in congenital bone disease osteogenesis imperfecta patients, is a cytoplasmic poly(A) polymerase playing a crucial role in regulating bone mineralization. Direct RNA sequencing revealed that TENT5A is induced during osteoblast differentiation and polyadenylates mRNAs encoding Col1α1, Col1α2, and other secreted proteins involved in osteogenesis, increasing their expression. We postulate that TENT5A, possibly together with its paralog TENT5C, is responsible for the wave of cytoplasmic polyadenylation of mRNAs encoding secreted proteins occurring during bone mineralization. Importantly, the Tent5a knockout (KO) mouse line displays bone fragility and skeletal hypomineralization phenotype resulting from quantitative and qualitative collagen defects. Thus, we report a biologically relevant posttranscriptional regulator of collagen production and, more generally, bone formation.

Postural balance, handgrip strength and mobility in Brazilian children and adolescents with osteogenesis imperfecta

ObjectiveTo describe postural balance, handgrip strength and mobility in children and adolescents with different types of osteogenesis imperfecta. MethodsCross-sectional study. Fifty selected subjects diagnosed with types I (n=11), III (n=21), and IV (n=18), followed up at Brazilian reference center for osteogenesis imperfecta in the Midwest region, aged 2–21 years (9.2±5.0), were enrolled in this study. Children and adolescents were evaluated for postural balance in the upright position with eyes-open and eyes-closed conditions, handgrip strength and the mobility domain (Pediatric Dysfunction Assessment Inventory). Data normality and difference between groups was verified. ResultsHandgrip strength was significantly lower in people with type III of osteogenesis imperfecta when compared to the osteogenesis imperfecta types I and IV, and to the age-specific reference data. Center of pressure length and mean velocity in the condition with eyes closed were worse compared to the open-eyes condition for children and adolescents with type I of osteogenesis imperfecta. There were worse results in the mobility domain for the participants classified with the most severe type of osteogenesis imperfecta. ConclusionsIt was observed that the severity of the osteogenesis imperfecta disease affected handgrip strength and locomotor function assessed by the mobility domain. Comparing osteogenesis imperfecta types, the higher the severity of osteogenesis imperfecta, the lower the handgrip strength. These results can contribute to new strategies of treatment focused on improving functional capacity and quality of life in people with osteogenesis imperfecta.

Molecular underpinnings of integrin binding to collagen-mimetic peptides containing vascular Ehlers–Danlos syndrome–associated substitutions

Collagens carry out critical extracellular matrix (ECM) functions by interacting with numerous cell receptors and ECM components. Single glycine substitutions in collagen III, which predominates in vascular walls, result in vascular Ehlers-Danlos syndrome (vEDS), leading to arterial, uterine, and intestinal rupture and an average life expectancy of <50 years. Collagen interactions with integrin α2β1 are vital for platelet adhesion and activation; however, how these interactions are impacted by vEDS-associated mutations and by specific amino acid substitutions is unclear. Here, we designed collagen-mimetic peptides (CMPs) with previously reported Gly → Xaa (Xaa = Ala, Arg, or Val) vEDS substitutions within a high-affinity integrin α2β1-binding motif, GROGER. We used these peptides to investigate, at atomic-level resolution, how these amino acid substitutions affect the collagen III-integrin α2β1 interaction. Using a multitiered approach combining biological adhesion assays, CD, NMR, and molecular dynamics (MD) simulations, we found that these substitutions differentially impede human mesenchymal stem cell spreading and integrin α2-inserted (α2I) domain binding to the CMPs and were associated with triple-helix destabilization. Although an Ala substitution locally destabilized hydrogen bonding and enhanced mobility, it did not significantly reduce the CMP-integrin interactions. MD simulations suggested that bulkier Gly → Xaa substitutions differentially disrupt the CMP-α2I interaction. The Gly → Arg substitution destabilized CMP-α2I side-chain interactions, and the Gly → Val change broke the essential Mg2+ coordination. The relationship between the loss of functional binding and the type of vEDS substitution provides a foundation for developing potential therapies for managing collagen disorders.

Bone biology: insights from osteogenesis imperfecta and related rare fragility syndromes.

The limited accessibility of bone and its mineralized nature have restricted deep investigation of its biology. Recent breakthroughs in identification of mutant proteins affecting bone tissue homeostasis in rare skeletal diseases have revealed novel pathways involved in skeletal development and maintenance. The characterization of new dominant, recessive and X-linked forms of the rare brittle bone disease osteogenesis imperfecta (OI) and other OI-related bone fragility disorders was a key player in this advance. The development of invitro models for these diseases along with the generation and characterization of murine and zebrafish models contributed to dissecting previously unknown pathways. Here, we describe the most recent advances in the understanding of processes involved in abnormal bone mineralization, collagen processing and osteoblast function, as illustrated by the characterization of new causative genes for OI and OI-related fragility syndromes. The coordinated role of the integral membrane protein BRIL and ofthe secreted protein PEDF in modulating bone mineralization as well as the function and cross-talk of the collagen-specific chaperones HSP47 and FKBP65 in collagen processing and secretion are discussed. We address the significance of WNT ligand, the importance of maintaining endoplasmic reticulum membrane potential and of regulating intramembrane proteolysis in osteoblast homeostasis. Moreover, we also examine the relevance of the cytoskeletal protein plastin-3 and of the nucleotidyltransferase FAM46A. Thanks to these advances, new targets for the development of novel therapies for currently incurable rare bone diseases have been and, likely, will be identified, supporting the important role of basic science for translational approaches.

Generation of a heterozygous COL1A1 (c.3969_3970insT) osteogenesis imperfecta mutation human iPSC line, MCRIi001-A-1, using CRISPR/Cas9 editing

To develop a disease model for the human ‘brittle bone’ disease, osteogenesis imperfecta, we have used gene editing to produce a facsimile of the patient heterozygous COL1A1 mutation in an established control iPSC line. The gene-edited line had a normal karyotype, expressed pluripotency markers and differentiated into cells representative of the three embryonic germ layers. This iPSC line and the isogenic parental iPSC line will be of use in exploring osteogenesis imperfecta disease mechanisms and therapeutic approaches in vitro.

Splicing defect in FKBP10 gene causes autosomal recessive osteogenesis imperfecta disease: a case report

BackgroundOsteogenesis imperfecta (OI) is a group of connective tissue disorder caused by mutations of genes involved in the production of collagen and its supporting proteins. Although the majority of reported OI variants are in COL1A1 and COL1A2 genes, recent reports have shown problems in other non-collagenous genes involved in the post translational modifications, folding and transport, transcription and proliferation of osteoblasts, bone mineralization, and cell signaling. Up to now, 17 types of OI have been reported in which types I to IV are the most frequent cases with autosomal dominant pattern of inheritance.Case PresentationHere we report an 8- year- old boy with OI who has had multiple fractures since birth and now he is wheelchair-dependent. To identify genetic cause of OI in our patient, whole exome sequencing (WES) was carried out and it revealed a novel deleterious homozygote splice acceptor site mutation (c.1257-2A > G, IVS7-2A > G) in FKBP10 gene in the patient. Then, the identified mutation was confirmed using Sanger sequencing in the proband as homozygous and in his parents as heterozygous, indicating its autosomal recessive pattern of inheritance. In addition, we performed RT-PCR on RNA transcripts originated from skin fibroblast of the proband to analyze the functional effect of the mutation on splicing pattern of FKBP10 gene and it showed skipping of the exon 8 of this gene. Moreover, Real-Time PCR was carried out to quantify the expression level of FKBP10 in the proband and his family members in which it revealed nearly the full decrease in the level of FKBP10 expression in the proband and around 75% decrease in its level in the carriers of the mutation, strongly suggesting the pathogenicity of the mutation.ConclusionsOur study identified, for the first time, a private pathogenic splice site mutation in FKBP10 gene and further prove the involvement of this gene in the rare cases of autosomal recessive OI type XI with distinguished clinical manifestations.

Patients with osteogenesis imperfecta disease walk with reduced ground reaction force compared to healthy subjects

Assessing the physical capacity of OI patients is important to evaluate disease progression and to adapt treatment, specifically rehabilitation protocol. While functional scores, such as the medical outcome study short form-36 (MOS SF-36) or the Oswestry disability index (ODI), are validated and used to assess physical capacity in this population, instrumented gait test could improve the evaluation. Analyzing ground reaction forces (GRF) during walking, which can be done with a single force plate, was shown to be an easy and efficient method to differentiate ambulatory pattern in relation to disease severity for a variety of musculoskeletal pathologies. This study tested the hypothesis that OI patients walk with smaller magnitude of vertical and fore-aft forces than control subjects. Gait analysis was performed for 6 OI patients (2 males; 27 ± 9 years old; 26 ± 3 kg m 2 ) and 12 healthy subjects (7 males; 24 ± 2 years old; 22 ± 2 kg/m 2 ). Each study participant walked several trials at self-selected normal speed in a lab equipped with floor-mounted forceplates (Kistler, CH). One leg was randomly selected for analysis and standard characteristic peaks in vertical and fore-aft GRF were measured for each step of the selected leg on a forceplate. To allow comparison among participants, GRF were normalized to percent bodyweight (%BW). Measurements were averaged across trials in order to have one value per GRF peak and participant. Finally, two tailed unpaired t-tests were done to compare GRF peaks between both groups at an alpha level of 5%. OI patients walked with significantly reduced vertical GRF during loading response (88 ± 19 Vs 114 ± 8%BW; P P P = 0.03) and reduced fore force during terminal stance (17 ± 3 Vs 22 ± 4%BW; P = 0.01). OI patients walked slower than controls (1.22 ± 0.14 Vs 1.47 ± 0.20 m/s; P = 0.02). This study showed a significantly lower GRF in OI patients. Smaller GRF were specifically hypothesized in this study due to muscle weakness, proprioceptive acuity diminution and fear of falling in this population. These expected results suggest that a single force plate can already provide valuable information to characterize the ambulatory function of OI patients. The case control comparison yielded results, which were congruent with gait alterations, previously reported in OI and hyperlaxity patients. Further study is needed to evaluate specific change in GFR among OI patients with functional treatment.

Loss of Type I Collagen Telopeptide Lysyl Hydroxylation Causes Musculoskeletal Abnormalities in a Zebrafish Model of Bruck Syndrome.

Bruck syndrome (BS) is a disorder characterized by joint flexion contractures and skeletal dysplasia that shows strong clinical overlap with the brittle bone disease osteogenesis imperfecta (OI). BS is caused by biallelic mutations in either the FKBP10 or the PLOD2 gene. PLOD2 encodes the lysyl hydroxylase 2 (LH2) enzyme, which is responsible for the hydroxylation of lysine residues in fibrillar collagen telopeptides. This hydroxylation directs crosslinking of collagen fibrils in the extracellular matrix, which is necessary to provide stability and tensile integrity to the collagen fibrils. To further elucidate the function of LH2 in vertebrate skeletal development, we created a zebrafish model harboring a homozygous plod2 nonsense mutation resulting in reduced telopeptide hydroxylation and crosslinking of bone type I collagen. Adult plod2 mutants present with a shortened body axis and severe skeletal abnormalities with evidence of bone fragility and fractures. The vertebral column of plod2 mutants is short and scoliotic with compressed vertebrae that show excessive bone formation at the vertebral end plates, and increased tissue mineral density in the vertebral centra. The muscle fibers of mutant zebrafish have a reduced diameter near the horizontal myoseptum. The endomysium, a layer of connective tissue ensheathing the individual muscle fibers, is enlarged. Transmission electron microscopy of mutant vertebral bone shows type I collagen fibrils that are less organized with loss of the typical plywood-like structure. In conclusion, plod2 mutant zebrafish show molecular and tissue abnormalities in the musculoskeletal system that are concordant with clinical findings in BS patients. Therefore, the plod2 zebrafish mutant is a promising model for the elucidation of the underlying pathogenetic mechanisms leading to BS and the development of novel therapeutic avenues in this syndrome. © 2016 American Society for Bone and Mineral Research.

Microstructural and Photoacoustic Infrared Spectroscopic Studies of Human Cortical Bone with Osteogenesis Imperfecta

The molecular basis of bone disease osteogenesis imperfecta (OI) and the mineralization of hydroxyapatite in OI bone have been of significant research interest. To further investigate the mechanism of OI disease and bone mineralization, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, and x-ray diffraction (XRD) are used in the present study to describe the structural and compositional differences between OI and healthy bone. OI bone exhibits more porous, fibrous features, abnormal collagen fibrils, and abnormal mineral deposits. Likewise, photoacoustic-FTIR experiments indicate an aberrant collagen structure and an altered mineral structure in OI. In contrast, there is neither significant difference in the non-collagenous proteins (NCPs) composition observed nor apparent change in the crystal structure between OI and healthy bone minerals as shown in XRD and energy-dispersive x-ray spectroscopy (EDS) results. This observation indicates that the biomineralization process is more controlled by the bone cells and non-collagenous phosphorylated proteins. The present study also confirms that there is an orientational influence on the stoichiometry of the mineral in OI bone. Also, a larger volume of the hydrated layer in the transverse plane than the longitudinal plane of the mineral crystal structure is proposed. The appearance of a new C–S band in the FTIR spectra in OI bone suggests the substitution of glycine by cysteine in collagen molecules or/and an increased amount of cysteine-rich osteonectin that relates to mineral nucleation and mineral crystal formation.

Local amino acid sequence patterns dominate the heterogeneous phenotype for the collagen connective tissue disease Osteogenesis Imperfecta resulting from Gly mutations.

Osteogenesis Imperfecta (OI), a hereditary connective tissue disease in collagen that arises from a single Gly → X mutation in the collagen chain, varies widely in phenotype from perinatal lethal to mild. It is unclear why there is such a large variation in the severity of the disease considering the repeating (Gly-X-Y)n sequence and the uniform rod-like structure of collagen. We systematically evaluate the effect of local (Gly-X-Y)n sequence around the mutation site on OI phenotype using integrated bio-statistical approaches, including odds ratio analysis and decision tree modeling. We show that different Gly → X mutations have different local sequence patterns that are correlated with lethal and nonlethal phenotypes providing a mechanism for understanding the sensitivity of local context in defining lethal and non-lethal OI. A number of important trends about which factors are related to OI phenotypes are revealed by the bio-statistical analyses; most striking is the complementary relationship between the placement of Pro residues and small residues and their correlation to OI phenotype. When Pro is present or small flexible residues are absent nearby a mutation site, the OI case tends to be lethal; when Pro is present or small flexible residues are absent further away from the mutation site, the OI case tends to be nonlethal. The analysis also reveals the dominant role of local sequence around mutation sites in the Major Ligand Binding Regions that are primarily responsible for collagen binding to its receptors and shows that non-lethal mutations are highly predicted by local sequence considerations alone whereas lethal mutations are not as easily predicted and may be a result of more complex interactions. Understanding the sequence determinants of OI mutations will enhance genetic counseling and help establish which steps in the collagen hierarchy to target for drug therapy.

Osteogenesis Imperfecta (Oi): A Case Report and Diagnosis Thinking Beyond Bone Fracture

Objectives: Most times in the medical practice, when we have a case of bone fracture, the patient is sent to the Orthopedic Department in order to treat locally the bone fracture with bone consolidation, without thinking at other diseases, of which the patient could suffer from and which in fact represent the real cause of the fracture, exception making the women at menopause, which make frequent fractures on background of osteoporosis and the cancers with different localizations complicate with bone metastasis, in these situations the fractures appear on pathologic bone and have a reserved prognosis. We should investigate further for other pathologies in order to find the real cause of the fracture. Methods: Present the case of a young girl aged 19, comes for a consultation with her mother with a complaint of fatigue, loss of appetite, lack of concentration and attention at school, getting tired easily after minimal physical and intellectual effort, the patient also mentions that about eight months ago she sustained a minor trauma to her left forearm which resulted in a fracture, which was then followed by a fracture of the radius and resulted in her being referred to the orthopedics department where her arm had to be fitted with metal rods. The principal signs was: bone deformation, bone shortening, thin bones, abnormally fragile bones, small muscles, joints and weak tendons, formation of thick scars, small somatic conformation, defective dentition (incomplete dentition , the teeth was damaged, the teeth falled quickly),the cornea was transparent blue(blue sclera) and also her mother had blue sclera. The molecular genetic test was used for clinic diagnosis confirmation and releaved mutations in COL1 A1 and COL1 A2 genes responsabile of sintesis of type I procollagen and confirmed the disease osteogenesis imperfecta. Results: The case of the fracture of the forearm was a very rare genetic disease - osteogenesis imperfecta- a congenital autosomal dominance. A.D. illness and occur even if only one parent transmits the effected gene. As in this case the daughter inherited the disease from her mother. Conclusions: Initially the case appeared to be a trivial case with a simple forearm bone fracture./Subsequently detailed physical examination revealed clinical signs such as somatic changes dentition and more importantly blue sclera pointing us towards the extremely rare disease osteogenesis imperfecta / An examination of the patient’s mother revealed the same signs, confirming the patient had inherited the autosomal dominant disease from her mother./Starting from a simple fracture and some nonspecific clinical symptoms, the final diagnosis was an unexpected surprise to finally discover a hereditary disease with autosomal dominant transmission which is extremely rare - osteogenesis imperfecta. This clinical case should point out that sometimes when a simple fracture is discovered there may be previously unknown underlying disease which may have contributed to the injury and fractures can also be caused by other bone disease./ The molecular genetic test was used for clinic diagnosis confirmation and releaved mutations in COL1 A1 and COL1 A2 genes responsabile of sintesis of type I procollagen and confirmed the disease osteogenesis imperfecta.

Investigation of the human disease osteogenesis imperfecta: A research‐based introduction to concepts and skills in biomolecular analysis

A blended approach encompassing problem-based learning (PBL) and structured inquiry was used in this laboratory exercise based on the congenital disease Osteogenesis imperfecta (OI), to introduce commonly used techniques in biomolecular analysis within a clinical context. During a series of PBL sessions students were presented with several scenarios involving a 2 year old child, who had experienced numerous fractures. Key learning goals related to both the theory and practical aspects of the course, covering biomolecular analysis and functional genomics, were identified in successive PBL sessions. The laboratory exercises were conducted in 3 hour blocks over six weeks, focused firstly on protein analysis, followed by nucleic acids. Students isolated collagen from normal and OI affected fibroblast cultures. Analysis by SDS-PAGE demonstrated α1 and α2 of collagen Type I chains at approximately 95 kDa and 92 kDa, respectively. Subtle differences in protein mobility between the control and OI samples were observed by some students, but most considered it inconclusive as a diagnostic tool. The nucleic acid module involved isolation of RNA from OI affected fibroblasts. The RNA was reverse transcribed and used as template to amplify a 354 bp COL1A1 fragment. Students were provided with the sequence of the OI affected COL1A1 PCR product aligned with the normal COL1A1 sequence, allowing identification of the mutation, as the substitution of Arg for Gly(976) of the triple helical region. Our experience with student cohorts over several years is that presentation of this laboratory exercise within a relevant clinical context, and the opportunity for active engagement with the experimental procedures via PBL sessions, supported the learning of basic theory and practical techniques of biomolecular analysis.

Variable expressivity of osteogenesis imperfecta in a Brazilian family due to p.G1079S mutation in the COL1A1 gene

Osteogenesis imperfecta (OI) is a Mendelian disease with genetic heterogeneity characterized by bone fragility, recurrent fractures, blue sclerae, and short stature, caused mostly by mutations in COL1A1 or COL1A2 genes, which encode the pro-α1(I) and pro-α2(I) chains of type I collagen, respectively. A Brazilian family that showed variable expression of autosomal dominant OI was identified and characterized. Scanning for mutations was carried out using SSCP and DNA sequence analysis. The missense mutation c.3235G>A was identified within exon 45 of the COL1A1 gene in a 16-year-old girl diagnosed as having OI type I; it resulted in substitution of a glycine residue (G) by a serine (S) at codon 1079 (p.G1079S). The proband's mother had the disease signs, but without bone fractures, as did five of nine uncles and aunts of the patient. All of them carried the mutation, which was excluded in four healthy brothers of the patient's mother. This is the first description in a Brazilian family with OI showing variable expression; only one among seven carriers for the c.3235G>A mutation developed bone fractures, the most striking clinical feature of this disease. This finding has a significant implication for prenatal diagnosis in OI disease.

Joint hypermobility with and without musculoskeletal complaints: a physiotherapeutic approach

IntroductionPhysiotherapists’ attitudes to hypermobility and its problems should be changing in ways which reflect current views on function, disability, and health. For example, rather than a focus on optimizing body functions, we should optimize activities and participation. We examined the current evidence base for guidance on the best therapeutic strategies when hypermobility is present.MethodsWe searched the databases Pubmed and Cinahl to find randomized controlled trials (RCTs) focusing on interventions for generalized joint hypermobility (GHM) and hypermobility syndrome (HMS).ResultsWe found three RCTs regarding HMS and GHM and one RCT regarding intervention in children with the collagen disease osteogenesis imperfecta. All the trials had some methodological problems but suggested that improvements may result from exercise, education, and training.ConclusionIntervention seems to be effective, as reported by experience and case reports but further research is required to identify appropriate exercise and training, according to the problems and capabilities of individual cases.

Robust physical methods that enrich genomic regions identical by descent for linkage studies: confirmation of a locus for osteogenesis imperfecta

BackgroundThe monogenic disease osteogenesis imperfecta (OI) is due to single mutations in either of the collagen genes ColA1 or ColA2, but within the same family a given mutation is accompanied by a wide range of disease severity. Although this phenotypic variability implies the existence of modifier gene variants, genome wide scanning of DNA from OI patients has not been reported. Promising genome wide marker-independent physical methods for identifying disease-related loci have lacked robustness for widespread applicability. Therefore we sought to improve these methods and demonstrate their performance to identify known and novel loci relevant to OI.ResultsWe have improved methods for enriching regions of identity-by-descent (IBD) shared between related, afflicted individuals. The extent of enrichment exceeds 10- to 50-fold for some loci. The efficiency of the new process is shown by confirmation of the identification of the Col1A2 locus in osteogenesis imperfecta patients from Amish families. Moreover the analysis revealed additional candidate linkage loci that may harbour modifier genes for OI; a locus on chromosome 1q includes COX-2, a gene implicated in osteogenesis.ConclusionTechnology for physical enrichment of IBD loci is now robust and applicable for finding genes for monogenic diseases and genes for complex diseases. The data support the further investigation of genetic loci other than collagen gene loci to identify genes affecting the clinical expression of osteogenesis imperfecta. The discrimination of IBD mapping will be enhanced when the IBD enrichment procedure is coupled with deep resequencing.