BACKGROUND: Osteogenesis imperfecta (OI) is a heritable skeletal disorder and comprises various subtypes that differ in clinical presentation, with Type I considered the least severe and Types III/IV the most severe forms. The study aim was to understand the OI patient diagnostic and treatment journey across Europe.
METHODS: We conducted a qualitative, descriptive study to understand the OI patient journey. A selection of people with OI/their caregivers and clinicians involved in OI-patient care from across Europe were interviewed using a specially developed questionnaire.
RESULTS: Between May 2022 and July 2022, 22 people with OI/caregivers and 22 clinicians (endocrinologists, orthopaedic surgeons, geneticists and metabolic specialists) from across Europe were interviewed. Our study showed various areas of concerns for the OI community. Timely diagnosis of OI is essential; misdiagnoses and a delay to treatment initiation are all too common. There are a lack of consensus guidelines regarding optimal treatments (including when bisphosphonate therapy should be initiated and the route of administration) and patient management throughout the duration of the patient\'s life. Adult OI patients do not have a medical home and are often managed by endocrinologists and rheumatologists. Adult care is often reactive based on the development of new symptoms. The psychosocial burden of OI impacts on the patient\'s quality of life.
CONCLUSIONS: There is an urgent need for increased awareness about OI and its wide range of symptoms. In particular, there is a need for consensus guidelines outlining the optimum care throughout the duration of the OI patient\'s life.

UNASSIGNED: Osteogenesis imperfecta (OI) is a genetic connective tissue disease defined by the loss of bone mass and density, which makes the bones more brittle and more likely to fracture over time. Bone deformity and articular instability are the subsequent symptoms.
UNASSIGNED: This 25-year-old man had malformed lower limbs and trouble walking due to OI and dwarfism. He arrived complaining of fever, nausea, vomiting and diffuse peri-umbilical pain. During ultrasonography a blinded, oedematous lobe formation containing an appendicolith was discovered. Acute suppurative appendicitis was diagnosed, necessitating a laparoscopic appendectomy. Because the patient had previously undergone general anaesthesia, anaesthesia was thought to be attainable. Pneumoperitoneum and a 10 mm optical port inserted into the umbilicus were used in the surgical procedure. A diagnostic laparoscopy revealed faecolith obstruction and an acute suppurative appendicitis. After an hour, a laparoscopic appendectomy was performed effectively with little blood loss. Without experiencing any difficulties because of the surgery position, the patient was discharged.
UNASSIGNED: We present a case of an OI dwarf patient with acute suppurative appendicitis. It highlights the possibility of performing laparoscopic surgery in general and a laparoscopic appendectomy in particular on OI patients.
CONCLUSIONS: In rare instances involving OI, laparoscopic surgery in general and laparoscopic appendectomy in particular are practical and efficient options.

Collagen posttranslational processing is crucial for its proper assembly and function. Disruption of collagen processing leads to tissue development and structure disorders like osteogenesis imperfecta (OI). OI-related collagen processing machinery includes prolyl 3-hydroxylase 1 (P3H1), peptidyl-prolyl cis-trans isomerase B (PPIB), and cartilage-associated protein (CRTAP), with their structural organization and mechanism unclear. We determine cryo-EM structures of the P3H1/CRTAP/PPIB complex. The active sites of P3H1 and PPIB form a face-to-face bifunctional reaction center, indicating a coupled modification mechanism. The structure of the P3H1/CRTAP/PPIB/collagen peptide complex reveals multiple binding sites, suggesting a substrate interacting zone. Unexpectedly, a dual-ternary complex is observed, and the balance between ternary and dual-ternary states can be altered by mutations in the P3H1/PPIB active site and the addition of PPIB inhibitors. These findings provide insights into the structural basis of collagen processing by P3H1/CRTAP/PPIB and the molecular pathology of collagen-related disorders.

Osteogenesis imperfecta (OI) is a rare congenital bone dysplasia characterized by high fracture rates and broad variations in clinical manifestations ranging from mild to increasingly severe and perinatal lethal forms. The underlying mutations affect either the synthesis or processing of the type I procollagen molecule itself or proteins that are involved in the formation and mineralization of the collagen matrix. Consequently, the collagen forming cells, the osteoblasts, become broadly dysfunctional in OI. Strikingly, hypermineralized bone matrix seems to be a frequent feature in OI, despite the variability in clinical severity and mutations in the so far studied different forms of human OI. While the causes of the increased mineral content of the bone matrix are not fully understood yet, there is evidence that the descendants of the osteoblasts, the osteocytes, which play a critical role not only in bone remodeling, but also in mineralization and sensing of mechanical loads, are also highly dysregulated and might be of major importance in the pathogenesis of OI. In this review article, we firstly summarize findings of cellular abnormalities in osteoblasts and osteocytes, alterations of the organic matrix, as well as of the microstructural organization of bone. Secondly, we focus on the hypermineralization of the bone matrix in OI as observed in several different forms of human OI as well as in animal models, its measurement and potential mechanical implications and its effect on the bone mineral density measured by dual X-ray absorptiometry. Thirdly, we give an overview of established medication treatments of OI and new approaches with a focus of their known or possible effects on the bone material, particularly on bone matrix mineralization.

BACKGROUND: Osteogenesis imperfecta (OI) is a connective tissue disorder in which the Type 1 collagen is defective. The eye is a structure rich in collagen Type 1 and is heavily impacted by the disease. Many vision-threatening eye diseases have been associated with OI. The onset of these diseases also tend to occur at an earlier age in individuals with OI. Despite the research on these risks, appropriate ophthalmological screening or care guidelines for individuals with OI remain unknown. As such, the purpose of this scoping review was to explore and describe existing ophthalmological screening and care guidelines to orient OI patient care.
METHODS: A scoping review based on the Joanna Briggs Institute (JBI) methodology was conducted. A search of databases (PubMed and Medline) was completed in consultation with a research librarian. A total of 256 studies were imported for screening. Primary sources matching the inclusion and exclusion criteria were screened, extracted, and analyzed using Covidence.
CONCLUSIONS: A total of 12 primary articles met inclusion and exclusion criteria, containing case reports, case series and cohort studies. Despite the risk of blindness associated with the consequences of OI on the eye, the primary literature fails to provide detailed screening and care guidelines aimed at identifying disease early. We provide general recommendations based on the review findings to guide the ophthalmological care of patients with OI and call upon the experts to convene globally to create screening guidelines. Further investigations of ophthalmological screening are warranted to limit these vision-threatening risks with early detection and treatment. Standardized ophthalmological screening guidelines for OI remain an area for research.

Rare diseases are an often an overlooked public health problem. Although they are infrequent, occurring on average in 100-500 people per million, these diseases represent a significant challenge in paediatric dentistry due to their complex manifestations and the need for specialised care. Conditions such as X-linked hypophosphatemic rickets (XLH), hypophosphatasia (HPP), and osteogenesis imperfecta (OI) exemplify the intersection of systemic health issues and oral health, requiring a multidisciplinary approach for their effective management. Dentists frequently play a crucial role in identifying genetic alterations through their dental manifestations and then referring patients to the geneticist for a definitive diagnosis. X-linked hypophosphatemia is the most common genetic form of rickets, with a prevalence of 1/20,000 - 1/60,000. XLH is characterised by stunted growth with disproportionate short stature, bowing of the lower limbs associated with reduced motor skills, osteoarticular pain, hypotonia, and dental and periodontal anomalies. XLH is due to inactivating mutations in the PHEX gene which cause excessive production of fibroblast growth factor 23 (FGF23). Increased concentration of FGF23 represents the main pathogenetic mechanism of XLH, stimulating urinary phosphate loss and renal 24-hydroxylase activity, and reducing renal 1α-hydroxylase activity with insufficient production of 1,25 -dihydroxy-vitamin D (1,25(OH)2D). PHEX protein is also expressed in osteoblasts, osteocytes, and odontoblasts. Regardless of FGF23\'s systemic effects on phosphate homeostasis, odontoblast differentiation, and dentin formation, its overexpression directly reduces osteoblast differentiation and matrix mineralisation. In patients with XLH, the deficit of 1,25(OH)2D induced by FGF23 causes poor enamel mineralisation with presence of cracks on teeth surface. XLH patients have recurrent dental abscesses with fistulas. Radiographic investigations highlight a generalised enlargement of the pulp chambers, molars with short roots, and a taurodontic appearance. Hypophosphatasia (HPP) is another condition in which dental manifestations precede systemic symptoms; it is a rare genetic disease (1/300,000 for severe forms, 1/100,000 for moderate forms. The incidence is perhaps underestimated due to missed diagnosis of moderate forms of the disease). It mainly affects bone and dental mineralisation. It is caused by pathogenic variant mutations in the ALPL gene which is located on the short arm of chromosome 1 and encodes the non-tissue-specific alkaline phosphatase (TNSALP) enzyme. TNSALP deficiency results in vitamin B6 (pyridoxine) deficiency and pathological accumulation of alkaline phosphatase substrates which may be responsible for extra-osseous manifestations, such as neurologic ones (pyridoxine sensitive seizures) as well as involvement of muscles and joints (arthropathies, muscle fatigue/hypotonia). Early non-traumatic loss of primary teeth between the ages of 2 and 4 years (and sometimes earlier) with an intact, non-resorbed root is a sign of disease. Tooth mobility precedes exfoliation of the tooth/teeth, most often without associated gum inflammation or pain. The primary incisors are the most affected teeth, and the number and type of primary teeth lost are proportional to the severity of the disease. From a radiologic perspective, characteristic signs include localised or generalised horizontal alveolar bone loss, large pulp chambers, intrapulpal calcifications, and reduced enamel thickness. Osteogenesis imperfecta, or brittle bone disease, is a rare condition characterised by bone fragility and osteopenia. It combines skeletal signs of varying severity (mainly fractures, hyperlaxity, and ligament deformities) and extra skeletal signs (bluish sclera, deafness, vascular fragility). It may also involve dentinogenesis imperfecta. The severity of clinical manifestations is highly variable, ranging from moderate forms that can go unnoticed to major forms that are lethal in the perinatal period. The birth prevalence of osteogenesis imperfecta is approximately 1 in 10,000 people. In approximately 90% of cases, it is an autosomal dominant disease due to monoallelic mutations in the COL1A1, COL1A2 or IFITM5 genes. Ten percent of cases are recessive forms characterised by dentinogenesis imperfecta, where the dental manifestations include teeth discoloration and weakness. The timely recognition of dental manifestations of these rare genetic diseases can allow providers to make an early diagnosis even prior to the development of systemic complications, and for this reason paediatric dentists have a key role in the recognition and management of these patients. Once the diagnosis is suspected, the dentist should refer patients for a genetic evaluation so as to ensure multidisciplinary management and initiation of medical therapies with the collaboration of paediatricians, endocrinologists and other health specialists. The role of dental professionals is not limited to the diagnosis of these rare diseases, but it also encompasses delivering specific, patient-tailored treatments, encouraging preventive care with regular dental visits and educating patients with the ultimate goal to promote not only oral health but the patient\'s overall wellbeing.

Fahr\'s disease is characterized by idiopathic bilateral deposition of calcium in the striopallidodentate area. We are presenting 83-year-old female, who failed responding while having lunch around 10 AM soon after she lost consciousness for an hour. It was associated with difficulty in walking, mood disturbances, fatigability, blurring of vision and occasional dizziness since past 4 months. Her neurological examination revealed Parkinsonian features. Her computed tomography of head report showed bilateral, symmetrical, large area of calcification over the basal ganglia, the thalamus and the cerebellum. To rule out the seizure disorder we have done an electroencephalogram and some laboratory test including calcium, Phosphorus, Parathyroid hormone and magnesium, vitamin D which were suggestive of Fahr\'s disease.

OBJECTIVE: Osteogenesis imperfecta (OI) is a rare genetic disease that is responsible for bone fragility, but also for dental malocclusions and dentinogenesis imperfecta (DI). The aim of this study was to assess whether the severity of dental malocclusion influenced the oral health-related quality of life (OHRQoL) and exposure to bullying in a paediatric OI population compared with a control group.
METHODS: Dental and occlusal characteristics were noted during oral and radiographic examination. The severity of malocclusion was assessed using the PAR index. P-CPQ, COHIP(34), and BCS-A questionnaires were used to evaluate, respectively, externally and self-perceived OHRQoL and bullying.
RESULTS: We included 39 patients with a mean age of 11.3 (±4.8 SD) in the OI group, and 45 patients with a mean age of 12.3 (±3.2 SD) in the control group. There were no significant differences between the two groups in terms of occlusal vertical and transverse dimensions. Patients with severe OI, presenting with bone fractures, bones deformities, and short stature, had significantly more anterior (p < 0.05) and posterior openbites (p < 0.05) and more DI (p < 0.05) compared to patients who had moderate or mild OI. Self-perceived OHRQoL was negatively impacted by the disease (p = 0.01), particularly in the domains of oral health (p < 0.05) and self-image (p < 0.001), but not by its severity. Exposure to bullying did not differ significantly between the two groups, although more patients with OI reported being teased (21.4% face to face and 7.1% online vs. 14.6% and 2.4% in the control group).
CONCLUSIONS: Interventions for dental malocclusion and oral health in OI patients would help to improve their quality of life and self-image.

UNASSIGNED: Osteogenesis imperfecta (OI) is a rare genetic disorder characterized by bone fragility. While skeletal manifestations are well documented, few studies have explored the effect of OI on the fetal heart. This retrospective case series investigates cardiac pathology in OI type II fetuses, aiming to address this gap.
UNASSIGNED: Medical records and autopsy reports of 6 genetically confirmed OI type II cases were examined. Fetuses had pathogenic variants in COL1A1 or PPIB, inducing structural defects in collagen type I. In addition to hematoxylin and eosin and Elastic van Gieson staining, the expression of collagen type I, COL1A1 and COL1A2 chains was examined by immunohistochemistry.
UNASSIGNED: Immunohistochemistry confirmed robust expression of collagen type I throughout the heart. Five fetuses had normal heart weight, while 1 had a low heart weight in the context of generalized growth retardation. None displayed structural heart anomalies.
UNASSIGNED: This study reveals robust collagen type I expression in the hearts of OI type II fetuses without structural anomalies. We hypothesize that collagen type I abnormalities may not be causative factors for heart anomalies during early embryonic development. Instead, their impact may be conceivably related to an increased susceptibility to degenerative changes later in life.

Excessive production of Transforming Growth Factor β (TGFβ) is commonly associated with dominant and recessive forms of OI. Previous reports have indicated that administration of TGFβ-targeted antibodies maybe of potential therapeutic benefit to OI patients. However, direct targeting of TGFβ is likely to cause multiple adverse effects including simulation of autoimmunity. In the current study we use patient-derived normal and OI fibroblasts, osteoblasts and OIM mouse models to determine the effects of Losartan, an angiotensin II receptor type 1 (AT1) antagonist, on TGFβ signalling and bone morphology in OI. In OIM mice bred on a mixed background administration of 0.6 g/L losartan for 4 weeks was associated with a significant reduction in TGFβ from 79.2 g/L in the control to 60.0 ng/ml following losartan (p < 0.05), reduced osteoclast activity as measured by CTX from 275.9 ng/ml in the control to 157.2 ng/ml following 0.6 g/L of losartan (p < 0.05) and increased cortical bone thickness (P < 0.001). Furthermore in OIM mice bred on a C57BL/6 background 0.6 g/L losartan increased trabecular bone volume in the tibiae (P < 0.05) and the vertebrae (P < 0.01), increased cortical bone thickness (P < 0.001) reduced the trabecular pattern factor (P < 0.01 and P < 0.001 for the tibiae and vertebrae respectively), reduced osteoclast (P < 0.05) and osteoblast (P < 0.01) numbers as well as reducing the area of bone covered by these cell types. Interestingly, losartan did not affect immune cells infiltrating into bone, nor did this drug alter TGFβ signalling in normal or OI fibroblasts. Instead, losartan reduced SMAD2 phosphorylation in osteoblasts, inhibiting their ability to differentiate. Our data suggest that losartan may be an effective treatment for the bone-associated dysmorphia displayed in OI whilst minimising potential adverse immune cell-related effects.