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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 -
Anatomical Record (Hoboken, N.J. : 2007) Mar 2024Osteogenesis imperfecta (OI), a disorder of type I collagen, causes skeletal deformities as well as defects in dental tissues, which lead to increased enamel wear and...
Osteogenesis imperfecta (OI), a disorder of type I collagen, causes skeletal deformities as well as defects in dental tissues, which lead to increased enamel wear and smaller teeth with shorter roots. Mice with OI exhibit similar microstructural dentin changes, including reduced dentin tubule density and dentin cross-sectional area. However, the effects of these mutations on gross dental morphology and dental tissue volumes have never been characterized in the osteogenesis imperfecta murine (OIM) mouse model. Here we compare mineralized dental tissue measurements of OIM mice and unaffected wild type (WT) littermates at the juvenile and adult stages. The maxillary and mandibular incisors and first molars were isolated from microCT scans, and tissue volumes and root length were measured. OIM mice have smaller teeth with shorter roots relative to WT controls. Maxillary incisor volumes differed significantly between OIM and WT mice at both the juvenile and young adult stage, perhaps due to shortening of the maxilla itself in OIM mice. Additionally, adult OIM mice have significantly less crown enamel volume than do juveniles, potentially due to loss through wear. Thus, OIM mice demonstrate a dental phenotype similar to humans with OI, with decreased tooth size, decreased root length, and accelerated enamel wear. Further investigation of dental development in the OIM mouse may have important implications for the development and treatment of dental issues in OI patients.
Topics: Mice; Humans; Animals; Osteogenesis Imperfecta; Collagen Type I; Phenotype; Mutation; Incisor; Disease Models, Animal
PubMed: 37638385
DOI: 10.1002/ar.25306 -
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 -
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 -
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 -
Pediatric Research Sep 2023Osteogenesis imperfecta (OI) is associated with short stature, which is mild, severe and moderate in OI types I, III and IV, respectively. Standardized OI type- and...
BACKGROUND
Osteogenesis imperfecta (OI) is associated with short stature, which is mild, severe and moderate in OI types I, III and IV, respectively. Standardized OI type- and sex-specific growth charts across all pediatric ages do not exist.
METHODS
We assessed 573 individuals with OI (type I, III or IV), each with at least one height measurement between ages 3 months and 20 years (total 6523 observations). Analogous to the Centers for Disease Control pediatric growth charts, we generated OI type- and sex-specific growth charts for infants (ages 3-36 months) as well as children and adolescents (ages 2-20 years). Growth curves were fitted to the data using the LMS method and percentiles were smoothed.
RESULTS
Age was associated with a decline in height z-scores (p < 0.001 for all OI types), which was more pronounced in females. Height multiplier curves were produced to predict adult height in children with OI. Among individuals with OI type I, those with COL1A1 pathogenic variants leading to haploinsufficiency were taller than those with COL1A1 or COL1A2 pathogenic variants not leading to haploinsufficiency.
CONCLUSION
Our standardized OI type- and sex-specific growth charts can be used to assess the growth of individuals with OI from infancy to adulthood.
IMPACT
Standardized osteogenesis imperfecta (OI) type- and sex-specific growth charts across all pediatric ages do not exist. Our study is the first to generate OI type- and sex-specific growth charts across all pediatric ages. Our height multiplier curves can be utilized to predict adult height in children with OI.
Topics: Male; Infant; Adult; Female; Adolescent; Humans; Child; Osteogenesis Imperfecta; Growth Charts; Collagen Type I; Body Height; Mutation
PubMed: 36922619
DOI: 10.1038/s41390-023-02550-0 -
Bone Dec 2023Missense variants in the MBTPS2 gene, located on the X chromosome, have been associated with an X-linked recessive form of osteogenesis imperfecta (X-OI), an inherited...
Mice heterozygous for an osteogenesis imperfecta-linked MBTPS2 variant display a compromised subchondral osteocyte lacunocanalicular network associated with abnormal articular cartilage.
Missense variants in the MBTPS2 gene, located on the X chromosome, have been associated with an X-linked recessive form of osteogenesis imperfecta (X-OI), an inherited bone dysplasia characterized by multiple and recurrent bone fractures, short stature, and various skeletal deformities in affected individuals. The role of site-2 protease, encoded by MBTPS2, and the molecular pathomechanism underlying the disease are to date elusive. This study is the first to report on the generation of two Mbtps2 mouse models, a knock-in mouse carrying one of the disease-causative MBTPS2 variants (N455S) and a Mbtps2 knock-out (ko) mouse. Because both loss-of-function variants lead to embryonic lethality in hemizygous male mutant mice, we performed a comprehensive skeletal analysis of heterozygous Mbtps2 and Mbtps2 female mice. Both models displayed osteochondral abnormalities such as thinned subchondral bone, altered subchondral osteocyte interconnectivity as well as thickened articular cartilage with chondrocyte clustering, altogether resembling an early osteoarthritis (OA) phenotype. However, distant from the joints, no alterations in the bone mass and turnover could be detected in either of the mutant mice. Based on our findings we conclude that MBTPS2 haploinsufficiency results in early OA-like alterations in the articular cartilage and underlying subchondral bone, which likely precede the development of typical OI phenotype in bone. Our study provides first evidence for a potential role of site-2 protease for maintaining homeostasis of both bone and cartilage.
Topics: Mice; Male; Female; Animals; Cartilage, Articular; Osteogenesis Imperfecta; Osteocytes; Bone and Bones; Osteoarthritis; Peptide Hydrolases
PubMed: 37797712
DOI: 10.1016/j.bone.2023.116927 -
BMJ Case Reports Nov 2023
Topics: Humans; Osteogenesis Imperfecta; Retina
PubMed: 37918942
DOI: 10.1136/bcr-2023-256366 -
Hormones (Athens, Greece) Jan 2024Sclerostin inhibits osteoblast activity by hampering activation of the canonical Wnt signaling pathway and simultaneously stimulates osteoclastogenesis through... (Review)
Review
Sclerostin inhibits osteoblast activity by hampering activation of the canonical Wnt signaling pathway and simultaneously stimulates osteoclastogenesis through upregulation of the receptor activator of NFκB ligand (RANKL). Thus, antibodies against sclerostin (Scl-Abs), besides promoting bone formation, suppress bone resorption and dissociate bone formation from resorption. This dual action results in remarkable increases of bone mineral density which are of a greater magnitude compared to the other antiosteoporotic treatments and are accompanied by decreases of fracture risk at all skeletal sites. The anabolic effect subsides after the first few months of treatment and a predominantly antiresorptive effect remains after this period, limiting its use to 12 months. Furthermore, these effects are largely reversible upon discontinuation; therefore, subsequent treatment with antiresorptives is indicated to maintain or further increase the bone gains achieved. Romosozumab is currently the only Scl-Ab approved for the treatment of severe postmenopausal osteoporosis. Indications for use in other populations, such as males, premenopausal women, and patients with glucocorticoid-induced osteoporosis, are pending. Additionally, the efficacy of Scl-Abs in other bone diseases, such as osteogenesis imperfecta, hypophosphatasia, X-linked hypophosphatemia, and bone loss associated with malignancies, is under thorough investigation. Cardiovascular safety concerns currently exclude patients at high cardiovascular risk from this treatment.
PubMed: 38170438
DOI: 10.1007/s42000-023-00521-y -
Acta Ortopedica Brasileira 2023This study aimed to assess the treatment of patients with Osteogenesis Imperfecta (OI) operated on with a telescopic Fassier-Duval (FD) rod in a querterenario hospital...
OBJECTIVES
This study aimed to assess the treatment of patients with Osteogenesis Imperfecta (OI) operated on with a telescopic Fassier-Duval (FD) rod in a querterenario hospital from 2010 to 2020.
METHODS
We analyzed indication for surgical treatment, causes of reoperation, complications and the effectiveness of telescoping rod.
RESULTS
The results were compared with the literature and with the same parameters from a previous study which a different telescopic rod developed by the same authors. This was a retrospective study based on the analysis of digital and radiographic clinical records. Fifteen patients with 21 FD rods were evaluated, most were used on the femur (18 rods or 85.7%), eight patients were female (53.3%), with a mean age of 10.47 (3.92 to 16.44) years, most of whom had type III Sillence (46.7%), with a mean follow-up of 5.22 (1.43 to 7.02) years. Seven rods (33.3%) had complications. The main indication was for fracture (57.1%). Regarding the ability to telescope, we observed that 15 rods (71.4%) followed the child's growth.
CONCLUSION
We had good results using FD rods, similar to the data found in the literature and the data obtained with our rod. .
PubMed: 37720808
DOI: 10.1590/1413-785220233103e266775