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A homozygous mutation causes osteogenesis and dentinogenesis imperfecta with craniofacial anomalies.JBMR Plus May 2024Osteogenesis imperfecta (OI) is a heterogeneous spectrum of hereditary genetic disorders that cause bone fragility, through various quantitative and qualitative defects...
Osteogenesis imperfecta (OI) is a heterogeneous spectrum of hereditary genetic disorders that cause bone fragility, through various quantitative and qualitative defects of type 1 collagen, a triple helix composed of two α1 and one α2 chains encoded by and , respectively. The main extra-skeletal manifestations of OI include blue sclerae, opalescent teeth, and hearing impairment. Moreover, multiple genes involved in osteoblast maturation and type 1 collagen biosynthesis are now known to cause recessive forms of OI. In this study a multiplex consanguineous family of two affected males with OI was recruited for genetic screening. To determine the causative, pathogenic variant(s), genomic DNA from two affected family members were analyzed using whole exome sequencing, autozygosity mapping, and then validated with Sanger sequencing. The analysis led to the mapping of a homozygous variant previously reported in SP7/OSX, a gene encoding for Osterix, a transcription factor that activates a repertoire of genes involved in osteoblast and osteocyte differentiation and function. The identified variant (c.946C > T; p.Arg316Cys) in exon 2 of results in a pathogenic amino acid change in two affected male siblings and develops OI, dentinogenesis imperfecta, and craniofacial anomaly. On the basis of the findings of the present study, :c. 946C > T is a rare homozygous variant causing OI with extra-skeletal features in inbred Arab populations.
PubMed: 38562913
DOI: 10.1093/jbmrpl/ziae026 -
JBMR Plus Jul 2023Intravenous (iv) bisphosphonates are widely used to treat the skeletal manifestations of osteogenesis imperfecta (OI). Obtaining peripheral iv access in pediatric...
Intravenous (iv) bisphosphonates are widely used to treat the skeletal manifestations of osteogenesis imperfecta (OI). Obtaining peripheral iv access in pediatric patients with OI is often difficult and traumatic. Although this may be mitigated with surgically placed iv ports (port-a-caths), surgeons may be hesitant to perform this procedure on these children because of the lack of safety data. This study aims to gain better insight into the safety and efficacy of port-a-cath use in this population and identify risk factors for port-a-cath complications. In the present study, we conducted a retrospective cohort analysis of patient characteristics and the incidence of port-a-cath-related complications in children with OI. Fifty-three port-a-caths were placed in 29 children (21 males and 8 females). Of the 29 patients, most are OI type III ( = 18), followed by type I ( = 4), type IV ( = 4), and type V ( = 3). At the time of initial port-a-cath placement, the median age was 52 months (10-191 months), and the median weight was 7.9 kg (5.1-41.1 kg). Most patients ( = 20) weighed less than 10 kg during initial placement. Weight correlated significantly with OI type ( = 0.048), sex ( = 0.03), and vessel used ( = 0.02). Median initial port-a-cath longevity was 43 months (1-113 months), and we found no significant difference in port-a-cath longevity between sexes, OI types, or vessels used. Most patients ( = 19) required multiple port-a-cath placements. There is a significant difference ( = 0.02) between the number of placements and OI type, with type IV having more than type III. Port-a-cath removal was almost always due to mechanical complications ( = 19) but also for infection ( = 1) and malposition ( = 1). Eight patients still had their initial port-a-caths in place at the conclusion of this study. These findings indicate that complications associated with port-a-cath placement are mild and can be used to safely deliver iv bisphosphonates to pediatric OI patients. © 2023 The Authors. published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
PubMed: 37457882
DOI: 10.1002/jbm4.10752 -
Journal of Bone and Mineral Research :... Nov 2023SNARE proteins comprise a conserved protein family responsible for catalyzing membrane fusion during vesicle traffic. Syntaxin18 (STX18) is a poorly characterized...
SNARE proteins comprise a conserved protein family responsible for catalyzing membrane fusion during vesicle traffic. Syntaxin18 (STX18) is a poorly characterized endoplasmic reticulum (ER)-resident t-SNARE. Recently, together with TANGO1 and SLY1, its involvement was shown in ER to Golgi transport of collagen II during chondrogenesis. We report a fetus with a severe osteochondrodysplasia in whom we identified a homozygous substitution of the highly conserved p.Arg10 to Pro of STX18. CRISPR/Cas9-mediated Stx18 deficiency in zebrafish reveals a crucial role for Stx18 in cartilage and bone development. Furthermore, increased expression of multiple components of the Stx18 SNARE complex and of COPI and COPII proteins suggests that Stx18 deficiency impairs antero- and retrograde vesicular transport in the crispant stx18 zebrafish. Taken together, our studies highlight a new candidate gene for a recessive form of osteochondrodysplasia, thereby possibly broadening the SNAREopathy phenotypic spectrum and opening new doors toward future research avenues. © 2023 American Society for Bone and Mineral Research (ASBMR).
Topics: Animals; Humans; Qa-SNARE Proteins; Zebrafish; Osteochondrodysplasias; Golgi Apparatus; Cartilage; Bone Development; Protein Transport
PubMed: 37718532
DOI: 10.1002/jbmr.4914 -
JCI Insight Nov 2023Osteogenesis imperfecta (OI), or brittle bone disease, is a disorder characterized by bone fragility and increased fracture incidence. All forms of OI also feature short...
Osteogenesis imperfecta (OI), or brittle bone disease, is a disorder characterized by bone fragility and increased fracture incidence. All forms of OI also feature short stature, implying an effect on endochondral ossification. Using the Aga2+/- mouse, which has a mutation in type I collagen, we show an affected growth plate primarily due to a shortened proliferative zone. We used single-cell RNA-Seq analysis of tibial and femoral growth plate tissues to understand transcriptional consequences on growth plate cell types. We show that perichondrial cells, which express abundant type I procollagen, and growth plate chondrocytes, which were found to express low amounts of type I procollagen, had ER stress and dysregulation of the same unfolded protein response pathway as previously demonstrated in osteoblasts. Aga2+/- proliferating chondrocytes showed increased FGF and MAPK signaling, findings consistent with accelerated differentiation. There was also increased Sox9 expression throughout the growth plate, which is expected to accelerate early chondrocyte differentiation but reduce late hypertrophic differentiation. These data reveal that mutant type I collagen expression in OI has an impact on the cartilage growth plate. These effects on endochondral ossification indicate that OI is a biologically complex phenotype going beyond its known impacts on bone to negatively affect linear growth.
Topics: Animals; Mice; Cartilage; Collagen Type I; Gene Expression; Osteogenesis Imperfecta
PubMed: 37796615
DOI: 10.1172/jci.insight.171984 -
Children (Basel, Switzerland) Aug 2023Osteogenesis Imperfecta (OI) is a rare genetic disorder in Type I collagen characterized by bone fractures, fragility, and deformity. Current treatments are focused on...
Osteogenesis Imperfecta (OI) is a rare genetic disorder in Type I collagen characterized by bone fractures, fragility, and deformity. Current treatments are focused on decreasing fracture rates, improving bone strength, and improving overall global function. Recent research has focused primarily on fracture fixation and outcomes of intramedullary rodding of long bones. While surgical techniques continue to evolve, recent trends in OI research are focusing on patient quality of life and patient-reported outcomes. We created a 12-question survey seeking information regarding aspects of orthopedic care that OI patients and families feel are the most pressing to improve. The survey was electronically administered, and 341 individuals participated. A total of 75% of respondents who answered the age question (254/335) were adults. Regarding surgical intervention for long bones, only 16% of respondents recall being told they could not have surgery because they were too young. Of the 16%, 37.8% were told that <5 years was too young, 13.4% <4 years was too young, and 48.8% <3 years of age was too young for surgical intervention for fractures or deformities. Nearly 22% of respondents were told that their bones were too small for intramedullary fixation. The patient and family responses help elucidate the topics requiring focus for the improvement of OI orthopedic care. Patient concerns and insights should drive the research questions we ask to advance the orthopedic care of OI patients.
PubMed: 37628344
DOI: 10.3390/children10081345 -
Frontiers in Endocrinology 2023The present study aims to describe a large cohort of Italian patients affected by osteogenesis imperfecta, providing a picture of the clinical bony and non-bony features...
INTRODUCTION
The present study aims to describe a large cohort of Italian patients affected by osteogenesis imperfecta, providing a picture of the clinical bony and non-bony features and the molecular background to improve knowledge of the disease to inform appropriate management in clinical practice.
METHODS
A total of 568 subjects (from 446 unrelated Italian families) affected by osteogenesis imperfecta who received outpatient care at Istituto Ortopedico Rizzoli from 2006 to 2021 were considered in the present study.
RESULTS
Skeletal and extraskeletal features were analyzed showing a lower height (mean z-scores equal to -1.54 for male patients and -1.47 for female patients) compared with the general Italian population. Half of the patient population showed one or more deformities, and most of the patients had suffered a relatively low number of fractures (<10). An alteration in the sclera color was identified in 447 patients. Similarly, several extraskeletal features, like deafness, dental abnormalities, and cardiac problems, were investigated. Additionally, inheritance and genetic background were evaluated, showing that most of the patients have a positive family history and the majority of pathogenic variants detected were on collagen genes, as per literature.
CONCLUSION
This study supports the definition of a clear picture of the heterogeneous clinical manifestations leading to variable severity in terms of skeletal and extra-skeletal traits and of the genetic background of an Italian population of osteogenesis imperfecta patients. In this perspective, this clearly highlights the crucial role of standardized and structured collection of high-quality data in disease registries particularly in rare disease scenarios, helping clinicians in disease monitoring and follow-up to improve clinical practice.
Topics: Humans; Male; Female; Osteogenesis Imperfecta; Cross-Sectional Studies; Fractures, Bone; Phenotype; Italy
PubMed: 38274230
DOI: 10.3389/fendo.2023.1299232 -
Journal of Endocrinological... Jan 2024To evaluate the genotypic and phenotypic relationship in a large cohort of OI patients and to compare the differences between eastern and western OI cohorts.
PURPOSE
To evaluate the genotypic and phenotypic relationship in a large cohort of OI patients and to compare the differences between eastern and western OI cohorts.
METHODS
A total of 671 OI patients were included. Pathogenic mutations were identified, phenotypic information was collected, and relationships between genotypes and phenotypes were analyzed. Literature about western OI cohorts was searched, and differences were compared between eastern and western OI cohorts.
RESULTS
A total of 560 OI patients were identified as carrying OI pathogenic mutations, and the positive detection rate of disease-causing gene mutations was 83.5%. Mutations in 15 OI candidate genes were identified, with COL1A1 (n = 308, 55%) and COL1A2 (n = 164, 29%) being the most common mutations, and SERPINF1 and WNT1 being the most common biallelic variants. Of the 414 probands, 48.8, 16.9, 29.2 and 5.1% had OI types I, III, IV and V, respectively. Peripheral fracture was the most common phenotype (96.6%), and femurs (34.7%) were most commonly affected. Vertebral compression fracture was observed in 43.5% of OI patients. Biallelic or COL1A2 mutation led to more bone deformities and poorer mobility than COL1A1 mutation (all P < 0.05). Glycine substitution of COL1A1 or COL1A2 or biallelic variants led to more severe phenotypes than haploinsufficiency of collagen type I α chains, which induced the mildest phenotypes. Although the gene mutation spectrum varied among countries, the fracture incidence was similar between eastern and western OI cohorts.
CONCLUSION
The findings are valuable for accurate diagnosis and treatment of OI, mechanism exploration and prognosis judgment. Genetic profiles of OI may vary among races, but the mechanism needs to be explored.
Topics: Humans; Osteogenesis Imperfecta; Collagen Type I, alpha 1 Chain; Fractures, Compression; Spinal Fractures; Collagen Type I; Genotype; Phenotype; Mutation; Bone Diseases, Metabolic
PubMed: 37270749
DOI: 10.1007/s40618-023-02123-2 -
BMJ Open Jun 2024Severe osteogenesis imperfecta (OI) is a debilitating disease with no cure or sufficiently effective treatment. Mesenchymal stem cells (MSCs) have good safety profile,...
An exploratory open-label multicentre phase I/II trial evaluating the safety and efficacy of postnatal or prenatal and postnatal administration of allogeneic expanded fetal mesenchymal stem cells for the treatment of severe osteogenesis imperfecta in infants and fetuses: the BOOSTB4 trial protocol.
INTRODUCTION
Severe osteogenesis imperfecta (OI) is a debilitating disease with no cure or sufficiently effective treatment. Mesenchymal stem cells (MSCs) have good safety profile, show promising effects and can form bone. The Boost Brittle Bones Before Birth (BOOSTB4) trial evaluates administration of allogeneic expanded human first trimester fetal liver MSCs (BOOST cells) for OI type 3 or severe type 4.
METHODS AND ANALYSIS
BOOSTB4 is an exploratory, open-label, multiple dose, phase I/II clinical trial evaluating safety and efficacy of postnatal (n=15) or prenatal and postnatal (n=3, originally n=15) administration of BOOST cells for the treatment of severe OI compared with a combination of historical (1-5/subject) and untreated prospective controls (≤30). Infants<18 months of age (originally<12 months) and singleton pregnant women whose fetus has severe OI with confirmed glycine substitution in or can be included in the trial.Each subject receives four intravenous doses of 3×10/kg BOOST cells at 4 month intervals, with 48 (doses 1-2) or 24 (doses 3-4) hours in-patient follow-up, primary follow-up at 6 and 12 months after the last dose and long-term follow-up yearly until 10 years after the first dose. Prenatal subjects receive the first dose via ultrasound-guided injection into the umbilical vein within the fetal liver (16+0 to 35+6 weeks), and three doses postnatally.The primary outcome measures are safety and tolerability of repeated BOOST cell administration. The secondary outcome measures are number of fractures from baseline to primary and long-term follow-up, growth, change in bone mineral density, clinical OI status and biochemical bone turnover.
ETHICS AND DISSEMINATION
The trial is approved by Competent Authorities in Sweden, the UK and the Netherlands (postnatal only). Results from the trial will be disseminated via CTIS, ClinicalTrials.gov and in scientific open-access scientific journals.
TRIAL REGISTRATION NUMBERS
EudraCT 2015-003699-60, EUCT: 2023-504593-38-00, NCT03706482.
Topics: Humans; Osteogenesis Imperfecta; Female; Pregnancy; Mesenchymal Stem Cell Transplantation; Infant; Clinical Trials, Phase I as Topic; Multicenter Studies as Topic; Infant, Newborn; Clinical Trials, Phase II as Topic; Mesenchymal Stem Cells; Treatment Outcome; Male; Fetal Stem Cells
PubMed: 38834319
DOI: 10.1136/bmjopen-2023-079767 -
BMJ Open Nov 2023Osteogenesis imperfecta (OI) is a rare genetic disease associated with multiple fractures throughout life. It is often treated with osteoporosis medications but their...
INTRODUCTION
Osteogenesis imperfecta (OI) is a rare genetic disease associated with multiple fractures throughout life. It is often treated with osteoporosis medications but their effectiveness at preventing fractures is unknown. The Treatment of Osteogenesis Imperfecta with Parathyroid Hormone and Zoledronic Acid trial will determine if therapy with teriparatide (TPTD) followed by zoledronic acid (ZA) can reduce the risk of clinical fractures in OI.
METHODS AND ANALYSIS
Individuals aged ≥18 years with a clinical diagnosis of OI are eligible to take part. At baseline, participants will undergo a spine X-ray, and have bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) at the spine and hip. Information on previous fractures and previous bone targeted treatments will be collected. Questionnaires will be completed to assess pain and other aspects of health-related quality of life (HRQoL). Participants will be randomised to receive a 2-year course of TPTD injections 20 µg daily followed by a single intravenous infusion of 5 mg ZA, or to receive standard care, which will exclude the use of bone anabolic drugs. Participants will be followed up annually, have a repeat DXA at 2 years and at the end of study. Spine X-rays will be repeated at the end of study. The duration of follow-up will range between 2 and 8 years. The primary endpoint will be new clinical fractures confirmed by X-ray or other imaging. Secondary endpoints will include participant reported fractures, BMD and changes in pain and HRQoL.
ETHICS AND DISSEMINATION
The study received ethical approval in December 2016. Following completion of the trial, a manuscript will be submitted to a peer-reviewed journal. The results will inform clinical practice by determining if TPTD/ZA can reduce the risk of fractures in OI compared with standard care.
TRIAL REGISTRATION NUMBER
ISRCTN15313991.
Topics: Humans; Adult; Adolescent; Zoledronic Acid; Teriparatide; Osteogenesis Imperfecta; Bone Density Conservation Agents; Quality of Life; Fractures, Bone; Bone Density; Pain; Randomized Controlled Trials as Topic
PubMed: 37993151
DOI: 10.1136/bmjopen-2023-078164 -
Calcified Tissue International Mar 2024Osteogenesis imperfecta (OI) is a rare genetic disorder caused by abnormal collagen type I production. While OI is primarily characterized by bone fragility and... (Review)
Review
Osteogenesis imperfecta (OI) is a rare genetic disorder caused by abnormal collagen type I production. While OI is primarily characterized by bone fragility and deformities, patients also have extraskeletal manifestations, including an increased risk of cardiovascular disease. This review provides a comprehensive overview of the literature on cardiovascular diseases in OI patients in order to raise awareness of this understudied clinical aspect of OI and support clinical guidelines. In accordance with the PRISMA guidelines, a systematic literature search in PubMed, Embase, Web of Science and Scopus was conducted that included articles from the inception of these databases to April 2023. Valvular disease, heart failure, atrial fibrillation, and hypertension appear to be more prevalent in OI than in control individuals. Moreover, a larger aortic root was observed in OI compared to controls. Various cardiovascular diseases appear to be more prevalent in OI than in controls. These cardiovascular abnormalities are observed in all types of OI and at all ages, including young children. As there are insufficient longitudinal studies, it is unknown whether these abnormalities are progressive in nature in OI patients. Based on these findings, we would recommend referring individuals with OI to a cardiologist with a low-threshold.
Topics: Child; Humans; Child, Preschool; Osteogenesis Imperfecta; Cardiovascular Diseases; Cardiovascular Abnormalities; Collagen Type I; Longitudinal Studies
PubMed: 38243143
DOI: 10.1007/s00223-023-01171-3