Home care needs assessment among caregivers of children and adolescents with osteogenesis imperfecta: a cross-sectional study

BACKGROUND

Children and adolescents with complex medical issues need home care services; however, few studies have provided insight into the unmet home care needs of the families of patients with osteogenesis imperfecta (OI). In this study, we aimed to assess the home care needs of caregivers of children and adolescents with OI and the associated factors.

METHODS

A self-administered questionnaire was administered online to 142 caregivers of patients with OI aged 3-17 years between May and October 2022 from 25 provinces in China. The questionnaire comprised 15 questions on demographic variables and 14 questions on home care needs. Chi-square analysis was used to compare group differences for categorical variables. Multivariate binary logistic regression analysis was conducted to examine predictors of caregivers' home care needs.

RESULTS

The study findings indicated that 81.5% of caregivers had high home care needs. The three leading types of home care needs were helping the child carry out physical fitness recovery exercises at home (72.5%), understanding precautions regarding treatment drugs (72.5%), and relieving the child's pain (70.4%). OI patients' poor self-care ability (adjusted odds ratio = 5.9, 95% confidence interval = 1.8-19.0) was related to caregivers' high level of home care needs.

CONCLUSIONS

The findings of this study suggest that future scientific research and nursing guidance should focus on OI patients' physical training, medication management, pain relief, fracture prevention, and treatment. In addition, caregivers of patients with poor self-care ability should receive special attention in the development of interventions. This study can help with addressing the unmet home care needs of caregivers of children and adolescents with OI. It is vital to develop a personalized intervention plan based on patients' self-care ability.

The impact of osteogenesis imperfecta severity on oral health-related quality of life in Spain: a cross-sectional study

BACKGROUND

Osteogenesis imperfecta (OI) affects dental and craniofacial development; therefore, it can influence oral health-related quality of life (OHRQoL). The objective of this study was to explore the influence of the severity of OI on OHRQoL in adults older than eighteen years residing in Spain.

METHOD

Adults with OI were recruited from the Spanish Association of Crystal Bone (AHUCE) foundation. OHRQoL was evaluated using the Spanish version of the Oral Health Impact Profile questionnaire (OHIP-14sp), oral hygiene habits, and a dental care survey. Clinical and radiological dental examinations were performed to evaluate the patients' oral conditions.

RESULTS

A total of 65 adults (n = 46 females) aged between nineteen and sixty-two years who were diagnosed with OI and classified as type I, III, and IV (n = 20, 14, and 31, respectively) participated in this research. The total OHIP-14sp scores were significantly greater (worse) for type III (23 [SD = 10]) and type IV (21.4 [SD = 12]) than for type I (13.8 [SD = 6]) (P < 0.05). The negative impact of OHRQoL was due to the association of type III OI with all domains except for the handicap domain, while type IV OI was associated with the physical disability, social disability, and handicap domains (P < 0.05 for all).

CONCLUSION

The severity of OI negatively impacted OHRQoL in adults. This association was statistically significant.

Short-term effects of Mediterranean diet on nutritional status in adults affected by Osteogenesis Imperfecta: a pilot study

BACKGROUND

Osteogenesis Imperfecta (OI) is a heterogeneous group of connective tissue disorders, characterized by varying degrees of skeletal fragility. Patients experience a range of comorbidities, such as obesity, cardiovascular, and gastrointestinal complications, especially in adulthood. All aspects that could benefit from dietary intervention. The aim of this study was to evaluate the effects of a 6-months restricted Mediterranean Diet (rMD) on nutritional status in adult patients affected by OI. We carried out a 6-months longitudinal pilot study. 14 adults (median age: 35 years; 7 women; 7 OI type III) where recruited in 2019 among the members of As.It.O.I., the Italian Association of Osteogenesis Imperfecta. As.It.O.I. All the evaluations were performed at the University of Milan, Italy. The rMD provided a reduction of 30% from daily total energy expenditure. 45% of calories derived from carbohydrates, 35% from fat and 0.7-1.0 g/kg of body weight from proteins. Comparisons of continuous variables after 6 months of intervention were performed by the paired t-test. All P-values were two-tailed, and p < 0.05 was considered significant.

RESULTS

Patients showed significant improvement in anthropometric measurements (BMI = 30.5 vs 28.1 kg/cm2, p < 0.001; Body Fat % = 32.9 vs 29.9, p = 0.006; Waist circumferences = 83.6 vs 79.6 cm; p < 0.001; Arm Fat Area = 29.8 vs 23.07 cm2; p < 0.011) and energy expenditure (REE/kg = 27.2 vs 29.2 kcal/kg, p < 0.001). Glucose and lipid profiles improved (Δglycemia = - 8.6 ± 7.3 mg/dL, p = 0.003; ΔTC = - 14.6 ± 20.1 mg/dL, p = 0.036; ΔLDL = - 12.0 ± 12.1 mg/dL, p = 0.009). Adherence to the MD significantly increased, moving from a moderate to a strong adherence and reporting an increased consumption of white meat, legumes, fish, nuts, fruits and vegetables.

CONCLUSION

A rMD was effective in improving nutritional status and dietary quality in adults with OI. These results underscores the need to raise awareness of nutrition as part of the multidisciplinary treatment of this disease.

The impact of craniofacial and dental osteogenesis imperfecta manifestations on oral health-related quality of life of children and adolescents

OBJECTIVE

Craniofacial and oral manifestations of Osteogenesis Imperfecta (OI) can affect the functioning of the stomatognathic system and impact the patient's quality of life. The objective of the study was to evaluate the relationship between craniofacial and oral manifestations and the Oral Health-related Quality of Life (OHRQoL) of OI children and adolescents.

MATERIAL AND METHODS

A total of 30 OI patients aged eight to fourteen years old followed up at the Oral Care Center for Inherited Diseases were enrolled in the research. OHRQoL was assessed using the short form of the Child Perceptions Questionnaire (CPQ) for eight to ten-year-olds (CPQ8-10) and 11 to 14-year-olds (CPQ11-14). The relationship between the OHRQoL index and its assessment domains, OI types, and the presence of dentinogenesis imperfecta (DI), class III malocclusion, and dental agenesis were evaluated.

RESULTS

The median CPQ score of patients was 5, and there was no significant difference in OHRQoL between children and adolescents, nor associated with the disease severity or the presence of DI. The oral manifestations evaluated did not directly impact the patients' OHRQoL.

CONCLUSIONS

The study demonstrated that the perception of OHRQoL is similar for both adolescents and children. The oral symptom was the most relevant domain for the index among patients aged eight to fourteen years while the emotional well-being was the most impacted.

CLINICAL RELEVANCE

this study makes contributions by indicating that addressing dental care for children and adolescents with OI is important in clinical management and better OHRQoL for this population.

Bleeding assessment in a large cohort of patients with Osteogenesis Imperfecta

BACKGROUND

Osteogenesis Imperfecta (OI) is characterised by bone fragility. Among several features, easy bruising and multiple case reports on haemorrhagic events have been reported. This paper describes the diverse manifestations of bleeding and bruising in a large cohort of 328 OI patients. The aim of this study is to provide insight in the diverse aspects and therapeutic considerations of bleedings in OI.

METHODS

This descriptive cohort study was conducted at the National Expert Center for adults with OI in the Netherlands. Bleeding was assessed by the validated self-bleeding assessment tool (Self-BAT) The tool was distributed among 328 adults with different clinically confirmed types of OI.

RESULTS

195 of 328 invited patients (completion rate 60%) with OI type 1 (n = 144), OI type 3 (n = 17) and OI type 4 (n = 34), aged between 18 and 82 years, completed the tool. Self-BAT scores were above the normal range in 42% of all patients. For males Self-BAT scores were increased in 37% with a mean score of 3.7, ranged between 0 and 18. For females the Self-BAT scores were increased in 44% with a mean of 5.4 and a range of 0-24. No statistical differences in OI subtypes were found.

CONCLUSIONS

Bleeding tendency appears to be a relevant complication in OI patients as this study confirms the presumption of bleeding tendency. There are specific recommendations to clinicians who treat OI patients to consider an assessment of bleeding tendency and use potential interventions to reduce haemorrhagic complications and improve quality of life.

An FGFR2 mutation as the potential cause of a new phenotype including early-onset osteoporosis and bone fractures: a case report

Osteoporosis is a systemic, multifactorial disorder of bone mineralization. Many factors contributing to the development of osteoporosis have been identified so far, including gender, age, nutrition, lifestyle, exercise, drug use, as well as a range of comorbidities. In addition to environmental and lifestyle factors, molecular genetic factors account for 50-85% of osteoporosis cases. For example, the vitamin D receptor (VDR), collagen type I (COL1), estrogen receptor (ER), apolypoprotein Е (ApoE), bone morphogenetic protein (BMP), and Low-density lipoprotein receptor-related protein 5 (LRP5) are all involved in the pathogenesis of osteoporosis. Among the candidate genes, the pathogenic variants in which are involved in the pathogenesis of osteoporosis is FGFR2. Additionally, FGFs/FGFRs-dependent signaling has been shown to regulate skeletal development and has been linked to a plethora of heritable disorders of the musculoskeletal system. In this study we present the clinical, biochemical and radiological findings, as well as results of molecular genetic testing of a 13-year-old male proband with heritable osteoporosis, arthralgia and multiple fractures and a family history of abnormal bone mineralization and fractures. Whole exome sequencing found a heterozygous previously undescribed variant in the FGFR2 gene (NM_000141.5) (GRCh37.p13 ENSG00000066468.16: g.123298133dup; ENST00000358487.5:c.722dup; ENSP00000351276.5:p.Asn241LysfsTer43). The same variant was found in two affected relatives. These data lead us to believe that the variant in FGFR2 found in our proband and his relatives could be related to their phenotype. Therefore, modern methods of molecular genetic testing can allow us to differentiate between osteogenesis imperfecta and other bone mineralization disorders.

"Osteogenesis Imperfecta Patients Wish Orthopedic Surgeons Had Better Strategies to Help with…"-Results of a Patient and Parent-Oriented Survey

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.

Pharmacological options in the treatment of osteogenesis imperfecta: A comprehensive review of clinical and potential alternatives

Osteogenesis imperfecta (OI) is a genetically heterogeneous connective tissue disorder characterized by bone fragility and different extra-skeletal manifestations. The severity of these manifestations makes it possible to classify OI into different subtypes based on the main clinical features. This review aims to outline and describe the current pharmacological alternatives for treating OI, grounded on clinical and preclinical reports, such as antiresorptive agents, anabolic agents, growth hormone, and anti-TGFβ antibody, among other less used agents. The different options and their pharmacokinetic and pharmacodynamic properties will be reviewed and discussed, focusing on the variability of their response and the molecular mechanisms involved to attain the main clinical goals, which include decreasing fracture incidence, improving pain, and promoting growth, mobility, and functional independence.

Influence of the Severity of Osteogenesis Imperfecta on Cranial Measurements

Osteogenesis Imperfecta (OI) is a disease that causes bone fragility and deformities, affecting both the cranial base and the craniocervical junction, and may lead to other neurological disorders. A retrospective cross-sectional study was carried out based on cephalometric analysis of the cranial base in a sample of patients with OI, in lateral skull radiographs and magnetic resonance imaging (MRI), comparing them with a sample of age-matched controls. When the different variables of the craniocervical junction were analyzed, significance was found in comparisons with the different age groups. All measurements of the variables studied stabilized as growth progressed. For most of the variables, the severity of the disease influences the measurements of the skull base, with statistically significant differences. Both age and severity of the disease are factors that directly influence the anatomy of the craniocervical junction in these patients and may serve as indicators in the early detection and prevention of other derived alterations.

Key4OI Recommendations for Lung Function Guidance in Osteogenesis Imperfecta: Based on an Internationally Performed Comprehensive International Consortium for Health Outcomes Measurement Procedure

INTRODUCTION

Pulmonary involvement in Osteogenesis Imperfecta (OI) can be severe but may be overlooked in milder cases. The Care4BrittleBones Foundation initiated this project to develop a set of global outcome measures focusing on respiratory-related issues in patients with OI. The objective was to reach an international consensus for a standardized set of outcomes and associated measuring instruments for the pulmonary care of individuals with OI. Based on the initial tests and questionnaires, we suggest parameters for when pulmonologists should seek guidance from the growing literature on OI pulmonary care and/or recognized experts in the field.

STUDY DESIGN AND METHODS

The project team consisted of a multidisciplinary mix of 12 people from six countries, including an OI patient representative, and facilitated by the Care4BrittleBones Foundation director. The International Consortium for Health Outcomes Measurement (ICHOM) process was followed, which includes the Delphi method, used to collect the opinions of the expert team. Patient input was present in each meeting due to the inclusion of a patient representative. In addition, online focus groups were held. They consisted of adults with OI from different countries, and they determined which questions matter the most to the OI community worldwide.

RESULTS

After three Delphi rounds, the expert team reached a consensus on the final set of measuring instruments, which included pulmonary function testing and patient self-reporting of symptoms related to breathing and sleep. Two questionnaires were decided upon: St. George's Respiratory Questionnaire (shortened version) and four questions regarding sleep. Patients should be screened for a history of pneumonia. Advanced testing for select patients by a pulmonologist would include further pulmonary function tests and a chest radiograph.

CONCLUSIONS

A standardized set of outcome measures related to pulmonary care of individuals with OI was determined based on what is important to both experts and patients. This included patient-reported outcome measures and basic pulmonary function testing. Using these outcome measures, it can be determined which patients are at high risk for pulmonary complications.

A progeroid syndrome caused by a deep intronic variant in TAPT1 is revealed by RNA/SI-NET sequencing

Exome sequencing has introduced a paradigm shift for the identification of germline variations responsible for Mendelian diseases. However, non-coding regions, which make up 98% of the genome, cannot be captured. The lack of functional annotation for intronic and intergenic variants makes RNA-seq a powerful companion diagnostic. Here, we illustrate this point by identifying six patients with a recessive Osteogenesis Imperfecta (OI) and neonatal progeria syndrome. By integrating homozygosity mapping and RNA-seq, we delineated a deep intronic TAPT1 mutation (c.1237-52 G>A) that segregated with the disease. Using SI-NET-seq, we document that TAPT1's nascent transcription was not affected in patients' fibroblasts, indicating instead that this variant leads to an alteration of pre-mRNA processing. Predicted to serve as an alternative splicing branchpoint, this mutation enhances TAPT1 exon 12 skipping, creating a protein-null allele. Additionally, our study reveals dysregulation of pathways involved in collagen and extracellular matrix biology in disease-relevant cells. Overall, our work highlights the power of transcriptomic approaches in deciphering the repercussions of non-coding variants, as well as in illuminating the molecular mechanisms of human diseases.

Investigating the psychometric properties of the EQ-5D-Y-3L, EQ-5D-Y-5L, CHU-9D, and PedsQL in children and adolescents with osteogenesis imperfecta

The objective of this study was to evaluate and compare the psychometric properties of the EQ-5D-Y-3L, EQ-5D-Y-5L, CHU-9D, and PedsQL, in a sample of children and adolescents with osteogenesis imperfecta (OI). A web-based cross-sectional survey was conducted among Chinese children and adolescents with OI in 2021. The EQ-5D-Y-3L, EQ-5D-Y-5L, CHU-9D, and PedsQL were used to assess the health-related quality of life for the participants. Construct validity, including convergent and divergent validity, known-group validity, and test-retest reliability, was examined to assess the psychometric properties of the measures. A total of 157 pediatric OI patients self-completed the questionnaire. Few of them reported the full health status. A strong ceiling effect was observed for all dimensions on the EQ-5D-Y and most on CHU-9D. Most dimensions of the EQ-5D-Y and CHU-9D showed statistically significant correlations with the hypothesized PedsQL subscales. The test-retest reliability for the EQ-5D-Y-3L, EQ-5D-Y-5L, and CHU-9D was acceptable. The EQ-5D-Y-5L showed a better known-group validity than EQ-5D-Y-3L, CHU-9D, and PedsQL in differentiating patients in risk groups.

CONCLUSION

The results confirmed that the EQ-5D-Y and CHU-9D are reliable and valid in pediatric OI patients. The EQ-5D-Y-5L performed better than EQ-5D-Y-3L regarding acceptability, convergent validity, and discriminatory power.

WHAT IS KNOWN

• Performance of the preference-based measures has never been reported in patients with Osteogenesis imperfecta.

WHAT IS NEW

• The EQ-5D-Y demonstrated higher sensitivity and discriminatory power than the CHU-9D in patients with osteogenesis Imperfecta • The EQ-5D-Y-3L performed slightly better than EQ-5D-Y-5L regarding convergent validity and discriminant ability.

Lung and chest wall volume during vital capacity manoeuvre in Osteogenesis Imperfecta

Background

Although Osteogenesis Imperfecta (OI) affects the connective tissue, pulmonary function might be compromised because of thoracic deformities. OI is known to be a restrictive lung disease, but spirometry provides global measurement without localizing the site of the restriction. Opto-electronic plethysmography (OEP), is a non-invasive method able to underline altered respiratory function as well as ventilatory thoraco-abdominal paradoxes during spontaneous breathing. We aimed to reconstruct the thoraco-abdominal surface, to perform local analyses of trunk motion and to make quantitative comparison of trunk shape and respiratory kinematics according to OI severity, particularly during maximal inspiratory and expiratory expansions. This is a cross-sectional study where we have studied the thoraco-abdominal compartmental analysis in 26 adult OI patients (14 Type III) at rest and during vital capacity manoeuvre using OEP. We have also applied a new method that created realistic and accurate 3D models to perform local analyses of trunk motion and to make quantitative comparison of trunk shape and respiratory kinematics.

Results

Type III patients were characterized by lower spirometric lung volume, by lower sleep quality, by a more compressed thoracic configuration aggravated by severe scoliosis, by reduced global expansion at rest and during maximal maneuvers because of the reduced expansion of the pulmonary ribcage at rest (12% vs. 65% in healthy subjects), during maximal inspiration (37% vs. 69%) and expiration (16% vs. 68%) with local paradoxical movement occurring on the side of the ribcage region.

Conclusion

The kinematics of the trunk changed to compensate for the severe structural deformities by shifting the expansion in the abdomen both at rest and during maximal manoeuvre because of a restricted thorax. For the first time, we have quantified and localized the site of the restriction in OI patients in the lateral part of the thorax. The 3D analysis proposed seemed a promising graphical immediate new method for pathophysiology study of chest wall restriction.

Evaluation of the Severity of Malocclusion in Children with Osteogenesis Imperfecta

Occlusion is the way in which the dental arches are related to each other and depends on craniofacial growth and development. It is affected in patients with Osteogenesis Imperfecta (OI) who present altered craniofacial development. The malocclusion present in 49 patients diagnosed with different types of OI aged between 4 and 18 was studied. The control group of healthy people was matched for age, sex, and molar class. To study the mixed and permanent dentition, the American Board of Orthodontics (ABO) discrepancy Index was applied. The primary dentition was evaluated with a Temporary Dentition Occlusion Analysis proposed for this study. The OI group obtained higher scores in the Discrepancy Index than the control group, indicating a high difficulty of treatment. The most significant differences were found in types III and IV of the disease. Regarding the variables studied, the greatest differences were found in the presence of lateral open bite in patients with OI, and in the variable "others" (agenesis and ectopic eruption). The analysis of primary dentition did not show significant differences between the OI and control groups. Patients with OI have more severe malocclusions than their healthy peers. Malocclusion is related to the severity of the disease and may progress with age.

Osteogenesis Imperfecta: characterization of fractures during pregnancy and post-partum

Background

Pregnancy and breastfeeding are associated with bone density loss. Fracture occurrence during pregnancy and post-partum, and its determinants, remain poorly known in Osteogenesis Imperfecta (OI). The aim of this study was to characterize fractures that occurred during pregnancy and post-partum in OI patients.

Results

We conducted a retrospective multicentric study including a total of 50 previously pregnant OI women from 10 Bone Centers in France. Among these patients, 12 (24%) patients experienced fractures during pregnancy or in the 6 months following delivery, and 38 (76%) did not experience any fracture. The most frequent localizations were: proximal femur (25%), spine (25%), distal femur (12.5%), and pelvis (12.5%). Fractures during pregnancy occurred during the third trimester and post-partum fractures occurred with a mean delay of 2 months following delivery. No fractures occurred during childbirth.

We next compared the 12 patients with pregnancy or post-partum fractures with the 38 patients without fractures. Mean age at pregnancy was 32.7 ± 3.1 years-old in the fractured group, vs 29.3 ± 5.0 years-old in the non-fractured group (p = 0.002). Breastfeeding was reported in 85.7% of patients in the fractured group, vs 47.1% in the non-fractured group (p = 0.03). All patients with post-partum fractures were breastfeeding. Bone mineral density was significantly lower in patients with pregnancy-related fractures compared with other patients: spine Z-score − 2.9 ± 1.6DS vs − 1.5 ± 1.7DS (p = 0.03), and total hip Z-score − 2.0 ± 0.7DS vs − 0.5 ± 1.4DS (p = 0.04). At least one osteoporosis-inducing risk factor or disease other than OI was identified in 81.8% vs 58.6% of fractured vs non-fractured patients (not significant). Fracture during pregnancy or post-partum was not associated with the severity of OI. Bisphosphonates before pregnancy were reported in 16.7% and 21.1% of patients with pregnancy-related fractures and non-fractured patients, respectively (not significant).

Conclusions

OI management during pregnancy and post-partum should aim for optimal control of modifiable osteoporosis risk factors, particularly in patients with low BMD. Breastfeeding should be avoided.

Clinical Manifestations and Medical Imaging of Osteogenesis Imperfecta: Fetal Through Adulthood

The aim of this paper is to describe the varying clinical and imaging manifestations of Osteogenesis Imperfecta (OI) in the fetus, the child, and the adult. OI is a genetic disorder with mutation of Type 1 and non-type 1 collagen genes that results in disruption of multiple collagen based organ systems, most notably bones, often leading to "brittle bones". Additional features such as blue sclera, dentinogenesis imperfecta, joint and ligamentous hyperlaxity, hearing loss and cardiac defects may be present. Currently, there are at least 30 recognized genetic forms of OI. Given the multiple genes involved, variable genetic inheritance, and the wide range in phenotype, diagnosis can be challenging. While OI may sometimes be diagnosed in the fetus, patients with mild forms of OI may be diagnosed in childhood or even in adulthood. Imaging, including ultrasound, radiography, computed tomography, and magnetic resonance imaging, plays an important role in the diagnoses of OI in the fetus, the child, and the adult. Imaging is also crucial in identifying the many multisystem manifestations of OI. In particular, imaging can help differentiate manifestations of OI from injuries sustained in non-accidental trauma. Age, severity and manner of presentation of OI vary broadly depending on the specific genetic mutation involved, mode of inheritance, and age of the patient. Successful diagnosis of OI hinges on a detailed knowledge of the variable presentation and complications that may be encountered with this disease. CONCLUSION: In conclusion, OI comprises a heterogeneous group of genetic disorders responsible for bone fragility and additional connective tissue disorders, which can result in specific clinical and imaging findings in the fetus, the child, and the adult.

Pathophysiology of respiratory failure in patients with osteogenesis imperfecta: a systematic review

INTRODUCTION

Respiratory failure is a major cause of death in patients with Osteogenesis Imperfecta. Moreover, respiratory symptoms seem to have a dramatic impact on their quality of life. It has long been thought that lung function disorders in OI are mainly due to changes in the thoracic wall, caused by bone deformities. However, recent studies indicate that alterations in the lung itself can also undermine respiratory health.

OBJECTIVES

Is there any intrapulmonary alteration in Osteogenesis Imperfecta that can explain decreased pulmonary function? The aim of this systematic literature review is to investigate to what extent intrapulmonary or extrapulmonary thoracic changes contribute to respiratory dysfunction in Osteogenesis Imperfecta.

METHODS

A literature search (in PubMed, Embase, Web of Science, and Cochrane), which included articles from inception to December 2020, was performed in accordance with the PRISMA guidelines.

RESULTS

Pulmonary function disorders have been described in many studies as secondary to scoliosis or to thoracic skeletal deformities. The findings of this systematic review suggest that reduced pulmonary function can also be caused by a primary pulmonary problem due to intrinsic collagen alterations.

CONCLUSIONS

Based on the most recent studies, the review indicates that pulmonary defects may be a consequence of abnormal collagen type I distorting the intrapulmonary structure of the lung. Lung function deteriorates further when intrapulmonary defects are combined with severe thoracic abnormalities. This systematic review reveals novel findings of the underlying pathological mechanism which have clinical and diagnostic implications for the assessment and treatment of pulmonary function disorders in Osteogenesis Imperfecta.KEY MESSAGESDecreased pulmonary function in Osteogenesis Imperfecta can be attributed to primary pulmonary defects due to intrapulmonary collagen alterations and not solely to secondary problems arising from thoracic skeletal dysplasia.Type I collagen defects play a crucial role in the development of the lung parenchyma and defects, therefore, affect pulmonary function. More awareness is needed among physicians about pulmonary complications in Osteogenesis Imperfecta to develop novel concepts on clinical and diagnostic assessment of pulmonary functional disorders.

Rough endoplasmic reticulum expansion: a consistent finding in a patient cohort with vascular Ehlers-Danlos Syndrome and Osteogenesis Imperfecta

Vascular Ehlers-Danlos Syndrome (vEDS) and Osteogenesis Imperfecta (OI) are two forms of connective tissue disorders. Previously, transmission electron microscopy of skin biopsies was routinely performed on all patients who were clinically suspected to have vEDS. At present, molecular genetics using genomic DNA extracted from a blood sample is the first line investigation for these patients. However, when variants of uncertain clinical significance are identified on genetic testing and individuals do not have the classical features of OI or vEDS, additional phenotypic information obtained from a skin biopsy can be valuable for contributing to the evidence for re-classifying pathogenicity of variants.We present a cohort of six patients with molecularly confirmed vEDS and one patient with a severe form of OI, who each had expanded (or dilated), protein-filled, rough endoplasmic reticulum identified on transmission electron microscopy. The patients were identified through retrospective screening of medical records, and biopsies were taken between 1999-2016. We discuss the potential role for assessing rough endoplasmic reticulum expansion as a useful tool to allow further phenotyping of these individuals.

Osteogenesis Imperfecta and hearing loss in the paediatric population

BACKGROUND

Osteogenesis Imperfecta is a genetic disorder affecting the synthesis of collagen in the body. It is also known as 'Brittle Bone Disease'. It is heterogenous in its clinical presentation. The commonest presentation is a history of frequent fractures, joint deformities and blue sclera. Secondary deformities of the extremities, spine, skull as well short stature observed frequently. Hearing loss has been well documented to occur in Osteogenesis Imperfecta. It is most commonly seen in types I, II and III. Hearing loss forms part of the diagnostic criteria for these types. Depending on the study, the prevalence of hearing loss in children with Osteogenesis imperfecta is between 6.7% and 77.3% The estimated prevalence of Osteogenesis Imperfecta is 1 in 20000.

OBJECTIVES

In South Africa, the commonest type of Osteogenesis Imperfecta was found to be Type III. The prevalence of OI Type III has been estimated to be between 1:125000 and 1:200000. Hearing loss is a common feature of OI Type III.

METHODS

This study was a Prospective Cross-sectional study. Ethics Approval was obtained from the University of Witwatersrand Ethics committee (Ethics number M190975) Children with Osteogenesis Imperfecta attending the Metabolic Bone Clinic at Chris Hani Baragwanath Academic Hospital were the target group. The patients and their parents or guardians were recruited at the clinic after a consent and or an assent was obtained. An Otoscopy followed by tympanometry and a hearing screen based on the age of the patient was done. DPEOAEs were also done as a screening test to confirm the pure tone audiogram findings. The results were given to the patients and their parents/guardians immediately.

RESULTS

The paediatric patients with Osteogenesis Imperfecta who consented to take part in the study had their hearing screen done at the Audiology Department at Chris Hani Baragwanath Academic Hospital. All of the children were found to have normal hearing. On tympanometry, all except 2 were found to have type A curves in bilaterally. Two patients had a type As curve in one ear with an A curve on the other side.

CONCLUSION

Hearing loss in Osteogenesis Imperfecta forms part of the diagnostic criteria for certain types of this genetic disorder. Hearing loss in the paediatric patients does not seem to be as prevalent as previously thought. All the patients involved in the study were receiving the bisphosphonate therapy (Zoledronic acid) for OI. This may possibly cause a delay in the onset of hearing loss but long term follow-up studies and bigger sample sizes will be required to prove this hypothesis.

Eat, breathe, sleep with Osteogenesis Imperfecta

BACKGROUND

Although Osteogenesis Imperfecta (OI) affects the connective tissue causing extremely brittle bones with consequent skeletal deformities, it is important to go beyond bones. Indeed, the quality of life in OI does not only depend on bones status, as OI might affect also other important functions. We have therefore implemented a multidisciplinary study to assess lung function, breathing pattern, sleep quality and nutritional status in 27 adult OI type III and IV patients (median age: 34.6 years; 19 women; 14 type III).

RESULTS

According to nocturnal oxygen desaturation, two groups were identified: 13 patients with (OI_OSA, incidence: 48.2%) and 14 without (no_OSA) obstructive sleep apnea. The former was characterized by higher spinal and ribcage deformity, by more restrictive lung function, by paradoxical thoracic breathing in supine position, by rapid and shallow breathing, by higher body mass index, by longer neck and waist circumferences; by higher abdominal volume and by greater percentage of body fat mass, particularly localized in the trunk. The best predictor of OI_OSA was the negative value of the supine ribcage contribution to tidal volume, followed by the ratio between the neck and the waist circumferences with body height and the supine thoraco-abdominal volumes phase shift angle.

CONCLUSIONS

The pathophysiology of OI ensued a dangerous vicious circle, in which breathing, sleep and nutritional status are tightly linked, and they might all end up in negatively affecting the quality of life. The vicious circle is fed by some intrinsic characteristics of the disease (thoracic, cranial and mandibular deformities) and some bad daily habits of the patients (i.e. physical inactivity and low dietary quality). The former impacts on restricting the respiratory function, the latter makes Olers more prone to experience overweight or obesity. The main consequence is a high incidence of obstructive sleep apnea, which remains an underdiagnosed disorder in individuals with severe OI who are obese, with a neck to height ratio over than 31.6%, and characterized by paradoxical breathing in supine position. A multidisciplinary approach, including evaluations of breathing, sleep and nutrition, is required to better manage the disease and fulfil the maximizing well-being of OI patients.

Osteogenesis imperfecta tooth level phenotype analysis: Cross-sectional study

INTRODUCTION

Dental anomalies in Osteogenesis imperfecta (OI), such as tooth discoloration, pulp obliteration (calcified dental pulp space), and taurodontism (enlarged dental pulp space) vary between and within patients. To better understand the associations and variations in these anomalies, a cross-sectional study was designed to analyze the dental phenotype in OI patients at the individual tooth type.

METHOD

A cohort of 171 individuals with OI type I, III and IV, aged 3-55 years, were recruited and evaluated for tooth discoloration, pulp obliteration, and taurodontism at the individual tooth level, using intraoral photographs and panoramic radiographs.

RESULTS

Genetic variants were identified in 154 of the participants. Patients with Helical α1 and α2 glycine substitutions presented the highest prevalence of tooth discoloration, while those with α1 Haploinsufficiency had the lowest (<10%). C-propeptide variants did not cause discoloration but resulted in the highest pulp obliteration prevalence (~%20). The prevalence of tooth discoloration and pulp obliteration was higher in OI types III and IV and increased with age. Tooth discoloration was mainly observed in teeth known to have thinner enamel (i.e. lower anterior), while pulp obliteration was most prevalent in the first molars. A significant association was observed between pulp obliteration and tooth discoloration, and both were associated with a lack of occlusal contact. Taurodontism was only found in permanent teeth and affected mostly first molars, and its prevalence decreased with age.

CONCLUSION

The dental phenotype evaluation at the tooth level revealed that different genetic variants and associated clinical phenotypes affect each tooth type differently, and genetic variants are better predictors of the dental phenotype than the type of OI. Our results also suggest that tooth discoloration is most likely an optical phenomenon inversely proportional to enamel thickness, and highly associated with pulp obliteration. In turn, pulp obliteration is proportional to patient age, it is associated with malocclusion and likely related to immature progressive dentin deposition. Taurodontism is an isolated phenomenon that is probably associated with delayed pulpal maturation.

Leg lengthening and deformity correction in rare bone diseases: a multidisciplinary approach

Congenital and acquired conditions presenting with leg length discrepancy, leg deformity or short stature are not only a challenge for paediatric orthopaedic surgeons in terms of treatment options but may also involve a number of medical specialties due to the complex clinical manifestations of the diseases. Various surgical treatment options are available for these rare genetic diseases, including bone lengthening and growth inhibition techniques for lower limb discrepancy, as well as guided growth and other surgical procedures for correction of angular deformities. Surgical techniques may be similar, but the treatment plans and specific multidisciplinary approaches may differ. The present report is focused on paediatric orthopaedic and multidisciplinary aspects of the treatment of rare bone diseases. We address the clinical presentation of these diseases, gait and surgical procedures for conditions such as achondroplasia, X‑linked hypophosphatemia and osteogenesis imperfecta. We also provide a short overview of other rare bone diseases.

Bone density, fractures and the associated factors in iranian children and adolescent with Osteogenesis Imperfecta

Backround

Osteogenesis imperfecta(OI) is a frequent bone fragility disorder in children. The purpose of this study was to assess the BMD and Vitamin D level in children with OI in southern Iran.

Method

This case-control study was conducted on 23 children, clinically diagnosed as osteogenesis imperfecta and 23 age- and gender-matched healthy controls. Demographic and anthropometric data, biochemical parameters, puberty, sun exposure and physical activity were assessed. Bone mineral density (BMD) was measured by Dual-energy X-ray absorptiometry (DXA). Data analysis was done by SPSS22.

Results

Forty-three point four percent of OI patients and fifty-six point five percent of control group had vitamin D deficiency (P = 0.376). Thirteen OI patients (56%) had low bone mass for chronological age in lumbar area (P < 0.001). Fracture episodes during treatment was significantly influenced by time of Pamidronate start, courses of Pamidronate injection, puberty and sun exposure (P values = 0.015, 0.030, 0.044 and 0.032, respectively). Fracture episodes during treatment had significantly increased in patients who had received Pamidronate more than 3 years compared with those received less than 3 years(P values = 0.047).

Conclusions

This study showed that vitamin D deficiency is prevalent amongst OI children in southern Iran. More than half of the OI children had low bone mass for chronological age in lumbar area, despite receiving bisphosphonate therapy. The present results revealed that early initiation of Pamidronate and number of Pamidronate courses are associated with lower fracture rate. However, treatment period more than 3 years can have adverse effect on fracture rates.

Osteogenesis Imperfecta in neonatal period in Cameroon: A case report

Early forms of Osteogenesis Imperfecta should be considered as main etiology of bone deformities in newborns. Prenatal diagnosis and genetic counseling should be improved in Africa. Management of these children remains difficult in low-income countries.

Muscle-bone properties after prolonged voluntary wheel running in a mouse model of dominant severe osteogenesis imperfecta

OBJECTIVE

The objective of the current study is to assess the effect of a seven-week voluntary wheel running intervention on muscles and bones properties in a mouse model mimicking dominant severe osteogenesis imperfecta (OI).

METHODS

Female wild-type (WT) and OI (Col1a1^Jrt/+) mice either performed voluntarily wheel-running exercise for 7-weeks or remained sedentary. Running distance and speed, forelimb grip strength, isolated muscle force and fatigability as well as bone morphology and mechanical properties were assessed.

RESULTS

We demonstrate that female WT and OI mice voluntarily performed exercise, although OI mice exercised less than WT littermates. The exercise regimen increased soleus muscle masses in WT and OI but increased relative grip strength in WT mice only. Specific muscle force and fatigability were similar between WT and OI mice and did not improve with exercise. Furthermore, the exercise regimen did not improve the femoral architectural and biomechanical properties in OI mice.

CONCLUSION

Our study suggests that voluntary wheel running is not appropriate to assess the effects of exercise in a mouse model of OI. Findings from exercising OI mice model studies may not necessarily be transferable to humans.

Osteogenesis imperfecta type I: The role of deep phenotyping in a patient with a ruptured uterus

As molecular diagnosis of Osteogenesis Imperfecta has become more accessible, there is an increasing ability to consider additional techniques to undertake deep phenotyping of the patient. In this report, we present the details of a female patient with type I Osteogenesis Imperfecta caused due to a pathogenic COL1A1 variant, who suffered from uterine rupture during labour in her second pregnancy, at age 33. Her presentation, patient journey, and histological results are described. Collagen flowers were identified with electron microscopy of a skin biopsy, and the significance of these are explored. Two other recorded cases of women with Osteogenesis Imperfecta who developed uterine rupture are discussed. This report demonstrates the potential role for ultrastructural tissue examination and deep phenotyping, to allow further insights into the relationship between genotype and phenotype.

Reproductive options for families at risk of Osteogenesis Imperfecta: a review

Background

Osteogenesis Imperfecta (OI) is a rare genetic disorder involving bone fragility. OI patients typically suffer from numerous fractures, skeletal deformities, shortness of stature and hearing loss. The disorder is characterised by genetic and clinical heterogeneity. Pathogenic variants in more than 20 different genes can lead to OI, and phenotypes can range from mild to lethal forms. As a genetic disorder which undoubtedly affects quality of life, OI significantly alters the reproductive confidence of families at risk. The current review describes a selection of the latest reproductive approaches which may be suitable for prospective parents faced with a risk of OI. The aim of the review is to alleviate suffering in relation to family planning around OI, by enabling prospective parents to make informed and independent decisions.

Main body

The current review provides a comprehensive overview of possible reproductive options for people with OI and for unaffected carriers of OI pathogenic genetic variants. The review considers reproductive options across all phases of family planning, including pre-pregnancy, fertilisation, pregnancy, and post-pregnancy. Special attention is given to the more modern techniques of assisted reproduction, such as preconception carrier screening, preimplantation genetic testing for monogenic diseases and non-invasive prenatal testing. The review outlines the methodologies of the different reproductive approaches available to OI families and highlights their advantages and disadvantages. These are presented as a decision tree, which takes into account the autosomal dominant and autosomal recessive nature of the OI variants, and the OI-related risks of people without OI.

The complex process of decision-making around OI reproductive options is also discussed from an ethical perspective.

Conclusion

The rapid development of molecular techniques has led to the availability of a wide variety of reproductive options for prospective parents faced with a risk of OI. However, such options may raise ethical concerns in terms of methodologies, choice management and good clinical practice in reproductive care, which are yet to be fully addressed.

Bisphosphonate-related osteonecrosis of the jaws and dental surgery procedures in children and young people with osteogenesis imperfecta: A systematic review

BACKGROUND

Bisphosphonates (BPs) contrast the bone fragility and improve bone density in some metastatic cancers and bone diseases, such as Osteogenesis Imperfecta (OI). BPs use has been associated with osteonecrosis of the jaws (BRONJs) in adults needing for invasive dental procedures.

AIM

To conduct a systematic review on BRONJ occurrence after dental surgery in paediatric population under BPs therapy for OI, so as to identify the pre-surgical protocols adopted.

DESIGN

According to PRISMA guidelines, Pubmed, Web of Science (WoS) and Cochrane were investigated on September 2018, and re-checked on July 2019. Inclusion criteria were English-language papers on children/young adults (until 24 years old) reporting dental/oral surgery procedures.

RESULTS

Totally, 60 articles were found. After title/abstract reviews and duplicates exclusion, 22 eligible titles underwent full-text evaluation. Finally, 10 studies were included.

CONCLUSIONS

The lack of BRONJ occurrence in paediatric population suffering OI and treated with BPs, was confirmed, but the reasons are still debated, being the BPs therapies and the surgical strategies various and not standardized. Longitudinal studies should evaluate what happens to those former children once adult, to evaluate the delayed BRONJs onset associated with the occurrence of comorbidities during the adulthood.

Combination therapy in the Col1a2G610C mouse model of Osteogenesis Imperfecta reveals an additive effect of enhancing LRP5 signaling and inhibiting TGFβ signaling on trabecular bone but not on cortical bone

Enhancing LRP5 signaling and inhibiting TGFβ signaling have each been reported to increase bone mass and improve bone strength in wild-type mice. Monotherapy targeting LRP5 signaling, or TGFβ signaling, also improved bone properties in mouse models of Osteogenesis Imperfecta (OI). We investigated whether additive or synergistic increases in bone properties would be attained if enhanced LRP5 signaling was combined with TGFβ inhibition. We crossed an Lrp5 high bone mass (HBM) allele (Lrp5^A214V) into the Col1a2^G610C/+ mouse model of OI. At 6-weeks-of-age we began treating mice with an antibody that inhibits TGFβ1, β2, and β3 (mAb 1D11), or with an isotype-matched control antibody (mAb 13C4). At 12-weeks-old, we observed that combining enhanced LRP5 signaling with inhibited TGFβ signaling produced an additive effect on femoral and vertebral trabecular bone volumes, but not on cortical bone volumes. Although enhanced LRP5 signaling increased femur strength in a 3-point bending assay in Col1a2^G610C/+ mice, femur strength did not improve further with TGFβ inhibition. Neither enhanced LRP5 signaling nor TGFβ inhibition, alone or in combination, improved femur 3-point-bending post-yield displacement in Col1a2^G610C/+ mice. These pre-clinical studies indicate combination therapies that target LRP5 and TGFβ signaling should increase trabecular bone mass in patients with OI more than targeting either signaling pathway alone. Whether additive increases in trabecular bone mass will occur in, and clinically benefit, patients with OI needs to be determined.

6'-Methoxy Raloxifene-analog enhances mouse bone properties with reduced estrogen receptor binding

Raloxifene (RAL) is an FDA-approved drug used to treat osteoporosis in postmenopausal women. RAL suppresses bone loss primarily through its role as a selective estrogen receptor modulator (SERM). This hormonal estrogen therapy promotes unintended side effects, such as hot flashes and increased thrombosis risk, and prevents the drug from being used in some patient populations at-risk for fracture, including children with bone disorders. It has recently been demonstrated that RAL can have significant positive effects on overall bone mechanical properties by binding to collagen and increasing bone tissue hydration in a cell-independent manner. A Raloxifene-Analog (RAL-A) was synthesized by replacing the 6-hydroxyl substituent with 6-methoxy in effort to reduce the compound's binding affinity for estrogen receptors (ER) while maintaining its collagen-binding ability. It was hypothesized that RAL-A would improve the mechanical integrity of bone in a manner similar to RAL, but with reduced estrogen receptor binding. Molecular assessment showed that while RAL-A did reduce ER binding, downstream ER signaling was not completely abolished. In-vitro, RAL-A performed similarly to RAL and had an identical concentration threshold on osteocyte cell proliferation, differentiation, and function. To assess treatment effect in-vivo, wildtype (WT) and heterozygous (OIM+/−) female mice from the Osteogenesis Imperfecta (OI) murine model were treated with either RAL or RAL-A from 8 weeks to 16 weeks of age. There was an untreated control group for each genotype as well. Bone microarchitecture was assessed using microCT, and mechanical behavior was assessed using 3-point bending. Results indicate that both compounds produced analogous gains in tibial trabecular and cortical microarchitecture. While WT mechanical properties were not drastically altered with either treatment, OIM+/− mechanical properties were significantly enhanced, most notably, in post-yield properties including bone toughness. This proof-of-concept study shows promising results and warrants the exploration of additional analog iterations to further reduce ER binding and improve fracture resistance.

Fatigue in adults with Osteogenesis Imperfecta

Background

Osteogenesis Imperfecta (OI) is characterized by bone fragility, and features such as blue sclerae, dentinogenesis imperfecta, hearing loss, ligamentous laxity and short stature can be present. It has long been assumed that the functional ability and quality of life of patients with OI depends primarily on the severity of skeletal deformities. However, fatigue is often mentioned in clinic by patients with all types of OI as an important modifier of their quality of life and does not always seem to be related to their functional ability. The aim of this study is to investigate whether adults with Osteogenesis Imperfecta are significantly more fatigued than the normal population.

Methods

The Fatigue Severity Scale (FSS) was distributed by mobile phone application among 151 adult patients with different OI types. Results of the FSS in the OI group were compared with two control populations from America (n = 20) and the Netherlands (n = 113).

Results

Ninety-nine patients (OI type 1 (n = 72), OI type 3 (n = 13), OI type 4 (n = 14) completed the FSS questionnaire. The mean FSS score of this cohort was 4.4 and significantly higher than the control populations (2.3/2.9). 65% of our cohort reported at least moderate fatigue compared with 2 control populations from America and the Netherlands.

Conclusion

Fatigue in patients with OI is a frequently encountered problem in our expert clinic but research into this topic is sparse. This pilot study is the largest study to date investigating fatigue in patients with OI and results have been compared with two control groups. The mean FSS score of 4.4 in the OI group indicates that people with OI are generally significantly more fatigued than the control population. Further evaluation of fatigue and its influencers in a larger group of OI patients is important for future management.

Plethora of Traumatic Lesions of Bilateral Knee Extensor Mechanism in Osteogenesis Imperfecta

INTRODUCTION

Injuries to the quadriceps extensor mechanism are rare in patients with Osteogenesis Imperfecta (OI). To the best of our knowledge, non-union of the patella in OI, either as an isolated problem or in combination with an acute fracture, has not been previously reported.

CASE REPORT

We describe how we surgically approached both the fracture and the non-union simultaneously. The surgical technique and steps are described in detail. Post-operative course was uneventful and the outcome was favorable, with full return of function for the patient.

CONCLUSION

A review of various knee extensor mechanism injuries in OI is described as illustrated in a single patient. The unusual simultaneous surgical treatment of a non-union and an acute fracture in the same patella shows that despite the severely compromised bone in this rare bone disease the bone still has a capacity to heal with a functional outcome.

Zoledronate and Raloxifene combination therapy enhances material and mechanical properties of diseased mouse bone

Current interventions to reduce skeletal fragility are insufficient at enhancing both the quantity and quality of bone when attempting to improve overall mechanical integrity. Bisphosphonates, such as Zoledronate (ZOL), are used to treat a variety of bone disorders by increasing bone mass to decrease fracture risk, but long-term use has been shown in some settings to compromise bone quality. Alternatively, Raloxifene (RAL) has recently been demonstrated to improve tissue quality and overall mechanical properties in a cell-independent manner by binding to collagen and increasing tissue hydration. We hypothesized that a combination of RAL and ZOL would improve mechanical and material properties of bone more than either monotherapy alone by enhancing both quantity and quality. In this study, wildtype (WT) and heterozygous (OIM+/-) male mice from the Osteogenesis Imperfecta (OI) murine model were treated with either RAL, ZOL, or both from 8 weeks to 16 weeks of age. Using the OIM model allows for investigation of therapeutic effects on a quality-based bone disease. Combination treatment resulted in higher trabecular architecture, cortical mechanical properties, and cortical fracture toughness in diseased mouse bone. Two fracture toughness properties, which are direct measures of the tissue's ability to resist the initiation and propagation of a crack, were significantly improved with combination treatment in OIM+/- compared to control. There was no significant effect on fracture toughness with either monotherapy alone in either genotype. Following the mass-based effects of ZOL, trabecular bone volume fraction was significantly higher with combination treatment in both genotypes. Combination treatment resulted in higher ultimate stress in both genotypes. RAL and combination treatment in OIM+/- also increased resilience compared to the control. In conclusion, this study demonstrates the beneficial effects of using combination drug treatments to increase bone mass while simultaneously improving tissue quality, especially to enhance the mechanical integrity of diseased bone. Combination therapies could be a potential method to improve bone health and combat skeletal fragility on both the microscopic and macroscopic levels.

Bleeding and bruising in Osteogenesis Imperfecta: International Society on Thrombosis and Haemostasis bleeding assessment tool and haemostasis laboratory assessment in 22 individuals

Osteogenesis imperfecta (OI) is characterized by susceptibility to bone fractures. Other symptoms, such as easy bruising and bleeding complications during surgery necessitating transfusions, have also been reported. The aim of the cross-sectional pilot study was to assess the bleeding and bruising tendency in OI patients and to screen for possible underlying haematological disorders. Bleeding tendency was investigated using the International Society on Thrombosis and Haemostasis bleeding assessment tool (ISTH-BAT) in 22 adult OI patients. Laboratory testing was performed to investigate for bleeding disorders or abnormal coagulation. Four patients [OI type 1(n = 3), OI type 4(n = 1)] had a bleeding score (BS) fitting with a bleeding tendency, but without test results pointing to a coagulopathy. Two patients [OI type 1(n = 1), OI type 3 (n = 1)] without a bleeding tendency according to the BS had increased fibrinolysis. This is the second largest study to date addressing bleeding tendency in OI and the first study to use ISTH-BAT and elaborate laboratory testing for coagulopathies. Four patients had an increased bleeding tendency. However, laboratory testing demonstrated no bleeding disorder or abnormal coagulation. Increased fibrinolysis was demonstrated in two patients without bleeding tendency on BS. Vascular fragility as a cause of bleeding tendency in OI has been suggested earlier. Further research on bleeding tendency in OI is important.

Bone dysplasias in 1.6 million births in Argentina

Currently accepted birth prevalence for osteochondrodysplasias (OCDs) is about 2 per 10,000 births. Our main goal is to estimate the prevalence of OCDs in Argentina and compare it with other surveillance systems. We examined 1,663,610 births among 160 hospitals of RENAC (Red Nacional de Anomalías Congénitas - National Network of Congenital Anomalies) between November 2009 and December 2016. Cases were detected and registered according to a pre-established protocol, ranked in three diagnostic evidence levels according to available clinical documentation, and categorized according to the 9th edition of the nosology and classification of genetic skeletal disorders. Within our dataset, the most frequent groups were Group-1 (FGFR3, chondrodysplasia) and Group-25 (Osteogenesis Imperfecta and decreased bone density). Birth prevalence per 10,000 for the main OCD types, were: Achondroplasia 0.47 (95% CI: 0.38-0.59), Thanatophoric Dysplasia 0.37 (95% CI: 0.29-0.48), and the Osteogenesis Imperfecta group 0.34 (95% CI: 0.26-0.44). For total OCD, birth prevalence was 2.20 per 10.000 births (95% CI: 1.98-2.44). RENAC prevalence of total OCDs was found to be lower than that reported by the Latin-American Study of Congenital Malformations (ECLAMC) and Utah Birth Defect Network but higher than EUROCAT. Our investigation is the first study of OCD prevalence in Argentina using data from every jurisdiction of the country.

Collagen Gly missense mutations: Effect of residue identity on collagen structure and integrin binding

Gly missense mutations in type I collagen, which replace a conserved Gly in the repeating (Gly-Xaa-Yaa)_n sequence with a larger residue, are known to cause Osteogenesis Imperfecta (OI). The clinical consequences of such mutations range from mild to lethal, with more serious clinical severity associated with larger Gly replacement residues. Here, we investigate the influence of the identity of the residue replacing Gly within and adjacent to the integrin binding ⁵⁰²GFPGER⁵⁰⁷ sequence on triple-helix structure, stability and integrin binding using a recombinant bacterial collagen system. Recombinant collagens were constructed with Gly substituted by Ala, Ser or Val at four positions within the integrin binding region. All constructs formed a stable triple-helix structure with a small decrease in melting temperature. Trypsin was used to probe local disruption of the triple helix, and Gly to Val replacements made the triple helix trypsin sensitive at three of the four sites. Any mutation at Gly505, eliminated integrin binding, while decreased integrin binding affinity was observed in the replacement of Gly residues at Gly502 following the order Val > Ser > Ala. Molecular dynamics simulations indicated that all Gly replacements led to transient disruption of triple-helix interchain hydrogen bonds in the region of the Gly replacement. These computational and experimental results lend insight into the complex molecular basis of the varying clinical severity of OI.

Bilateral giant retinal tears in Osteogenesis Imperfecta

Background

Osteogenesis imperfecta (OI) is a rare primarily autosomal dominant condition in which the connective tissues of bones, ligaments and sclerae do not form properly. Typically, mutations in COL1A1 and COL1A2 genes lead to the defective formation or quantity of type I collagen, the principle matrix in these tissues. Molecular genetic studies have now elucidated multiple genetic subtypes of the disorder but little literature exists on the risk of retinal tears and detachments in OI.

Case presentation

We report the first case of a child with a rare recessive type of OI, subtype VIII, resulting from a P3H1 (also known as LEPRE1) gene mutation presenting with bilateral giant retinal tears and the surgical challenges encountered in performing retinal detachment repair due to scleral thinning. The P3H1 gene encodes for prolyl 3-hydroxylase 1 which is involved in the post-translational modification of not only collagen type I but also types II and V which when mutated may result in pathological posterior vitreous detachment (PVD) and giant retinal tear detachments.

Conclusions

Genetic analyses are increasingly important in such cases and may guide patient monitoring and potential prophylactic treatment, known to significantly reduce the probability of giant retinal tear detachments in other high-risk collagenopathies such as Stickler Syndrome Type I.

Genetic causes and mechanisms of Osteogenesis Imperfecta

Osteogenesis Imperfecta (OI) is a genetic disorder characterized by various clinical features including bone deformities, low bone mass, brittle bones, and connective tissue manifestations. The predominant cause of OI is due to mutations in the two genes that encode type I collagen. However, recent advances in sequencing technology has led to the discovery of novel genes that are implicated in recessive and dominant OI. These include genes that regulate the post-translational modification, secretion and processing of type I collagen as well as those required for osteoblast differentiation and bone mineralization. As such, OI has become a spectrum of genetic disorders informing about the determinants of both bone quantity and quality. Here we summarize the known genetic causes of OI, animal models that recapitulate the human disease and mechanisms that underlie disease pathogenesis. Additionally, we discuss the effects of disrupted collagen networks on extracellular matrix signaling and its impact on disease progression.

Mutational analysis of COL1A1 and COL1A2 genes among Estonian osteogenesis imperfecta patients

Background

Osteogenesis imperfecta (OI) is a rare bone disorder. In 90% of cases, OI is caused by mutations in the COL1A1/2 genes, which code procollagen α1 and α2 chains. The main aim of the current research was to identify the mutational spectrum of COL1A1/2 genes in Estonian patients. The small population size of Estonia provides a unique chance to explore the collagen I mutational profile of 100% of OI families in the country.

Methods

We performed mutational analysis of peripheral blood gDNA of 30 unrelated Estonian OI patients using Sanger sequencing of COL1A1 and COL1A2 genes, including all intron-exon junctions and 5′UTR and 3′UTR regions, to identify causative OI mutations.

Results

We identified COL1A1/2 mutations in 86.67% of patients (26/30). 76.92% of discovered mutations were located in the COL1A1 (n = 20) and 23.08% in the COL1A2 (n = 6) gene. Half of the COL1A1/2 mutations appeared to be novel. The percentage of quantitative COL1A1/2 mutations was 69.23%. Glycine substitution with serine was the most prevalent among missense mutations. All qualitative mutations were situated in the chain domain of pro-α1/2 chains.

Conclusion

Our study shows that among the Estonian OI population, the range of collagen I mutations is quite high, which agrees with other described OI cohorts of Northern Europe. The Estonian OI cohort differs due to the high number of quantitative variants and simple missense variants, which are mostly Gly to Ser substitutions and do not extend the chain domain of COL1A1/2 products.

Application of anti-Sclerostin therapy in non-osteoporosis disease models

Sclerostin, a known inhibitor of the low density lipoprotein related protein 5 and 6 (LRP5 and LRP6) cell surface signaling receptors, is integral in the maintenance of normal bone mass and strength. Patients with loss of function mutations in SOST or missense mutations in LRP5 that prevent Sclerostin from binding and inhibiting the receptor, have significantly increased bone mass. This observation leads to the development of Sclerostin neutralizing therapies to increase bone mass and strength. Anti-Sclerostin therapy has been shown to be effective at increasing bone density and strength in animal models and patients with osteoporosis. Loss of function of Sost or treatment with a Sclerostin neutralizing antibody improves bone properties in animal models of Osteoporosis Pseudoglioma syndrome (OPPG), likely due to action through the LRP6 receptor, which suggests patients may benefit from these therapies. Sclerostin antibody is effective at improving bone properties in mouse models of Osteogenesis Imperfecta, a genetic disorder of low bone mass and fragility due to type I collagen mutations, in as little as two weeks after initiation of therapy. However, these improvements are due to increases in bone quantity as the quality (brittleness) of bone remains unaffected. Similarly, Sclerostin antibody treatment improves bone density in animal models of other diseases. Sclerostin neutralizing therapies are likely to benefit many patients with genetic disorders of bone, as well as other forms of metabolic bone disease.

Letter to the Editor: Therapies for Osteogenesis Imperfecta

N/A.

Enhanced Wnt signaling improves bone mass and strength, but not brittleness, in the Col1a1(+/mov13) mouse model of type I Osteogenesis Imperfecta

Osteogenesis Imperfecta (OI) comprises a group of genetic skeletal fragility disorders. The mildest form of OI, Osteogenesis Imperfecta type I, is frequently caused by haploinsufficiency mutations in COL1A1, the gene encoding the α1(I) chain of type 1 collagen. Children with OI type I have a 95-fold higher fracture rate compared to unaffected children. Therapies for OI type I in the pediatric population are limited to anti-catabolic agents. In adults with osteoporosis, anabolic therapies that enhance Wnt signaling in bone improve bone mass, and ongoing clinical trials are determining if these therapies also reduce fracture risk. We performed a proof-of-principle experiment in mice to determine whether enhancing Wnt signaling in bone could benefit children with OI type I. We crossed a mouse model of OI type I (Col1a1(+/Mov13)) with a high bone mass (HBM) mouse (Lrp5(+/p.A214V)) that has increased bone strength from enhanced Wnt signaling. Offspring that inherited the OI and HBM alleles had higher bone mass and strength than mice that inherited the OI allele alone. However, OI+HBM and OI mice still had bones with lower ductility compared to wild-type mice. We conclude that enhancing Wnt signaling does not make OI bone normal, but does improve bone properties that could reduce fracture risk. Therefore, agents that enhance Wnt signaling are likely to benefit children and adults with OI type 1.

Osteoblastic differentiation of bone marrow mesenchymal stromal cells in Bruck Syndrome

Background

Osteogenesis Imperfecta (OI) (OMIM %259450) is a heterogeneous group of inherited disorders characterized by increased bone fragility, with clinical severity ranging from mild to lethal. The majority of OI cases are caused by mutations in COL1A1 or COL1A2. Bruck Syndrome (BS) is a further recessively-inherited OI-like phenotype in which bone fragility is associated with the unusual finding of pterygia and contractures of the large joints. Notably, several studies have failed to show any abnormalities in the biosynthesis of collagen 1 in BS patientes. Evidence was obtained for a specific defect of the procollagen telopeptide lysine hydroxylation in BS, whereas mutations in the gene PLOD2 have been identified. Recently, several studies described FKBP10 mutations in OI-like and BS patients, suggesting that FKBP10 is a bonafide BS locus.

Methods

We analyzed the coding region and intron/exon boundaries of COL1A1, COL1A2, PLOD2 and FKBP10 genes by sequence analysis using an ABI PRISM 3130 automated sequencer and Big Dye Terminator Sequencing protocol. Mononuclear cells obtained from the bone marrow of BS, OI patients and healthy donors were cultured and osteogenic differentiation was induced. The gene expression of osteoblast specific markers were also evaluated during the osteoblastic differentiation of mesenchymal stem cell (MSC) by qRT-PCR using an ABI7500 Sequence Detection System.

Results

No mutations in COL1A1, COL1A2 or PLOD2 were found in BS patient. We found a homozygous 1-base-pair duplication (c.831dupC) that is predicted to produce a translational frameshift mutation and a premature protein truncation 17 aminoacids downstream (p.Gly278ArgfsX95). The gene expression of osteoblast specific markers BGLAP, COL1A1, MSX2, SPARC and VDR was evaluated by Real Time RT-PCR during differentiation into osteoblasts and results showed similar patterns of osteoblast markers expression in BS and healthy controls. On the other hand, when compared with OI patients, the expression pattern of these genes was found to be different.

Conclusions

Our work suggests that the gene expression profiles observed during mesenchymal stromal cell differentiation into osteoblast are distinct in BS patients as compared to OI patients. The present study shows for the first time that genes involved in osteogenesis are differentially expressed in BS and OI patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12881-016-0301-7) contains supplementary material, which is available to authorized users.

Echocardiographic Evidence of Early Diastolic Dysfunction in Asymptomatic Children with Osteogenesis Imperfecta

OBJECTIVES

Structural and functional cardiovascular abnormalities have been reported in adults with osteogenesis imperfecta (OI); however, there is a lack of paediatric literature on this topic. This study aimed to investigate cardiovascular abnormalities in children with OI in comparison to a control group.

METHODS

This case-control study was conducted at the Sultan Qaboos University Hospital in Muscat, Oman, between May 2013 and August 2014. Data from eight patients with OI and 24 healthy controls were compared using conventional and tissue Doppler echocardiography (TDE).

RESULTS

The OI group had significantly lower peak early mitral valve flow velocity (P = 0.027), peak a-wave reversal in the pulmonary vein (P = 0.030) and peak early diastolic velocity of the mitral valve and upper septum (P = 0.001 each). The peak late diastolic velocities of the mitral valve (P = 0.002) and the upper septum (P = 0.037) were significantly higher in the OI group; however, the peak early/late diastolic velocity ratios of the mitral valve (P = 0.002) and upper septum (P = 0.001) were significantly lower. Left ventricular dimensions and aortic and pulmonary artery diameters were larger in the OI group when indexed for body surface area. Both groups had normal systolic cardiac function.

CONCLUSION

Children with OI had normal systolic cardiac function. However, changes in myocardial tissue Doppler velocities were suggestive of early diastolic cardiac dysfunction. They also had increased left ventricular dimensions and greater vessel diameters. These findings indicate the need for early and detailed structural and functional echocardiographic assessment and follow-up of young patients with OI.

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.

Association between spondylolisthesis and L5 fracture in patients with Osteogenesis Imperfecta

PURPOSE

To investigate if an association between spondylolisthesis and L5 fracture occurs in patients affected by Osteogenesis Imperfecta (O.I.).

METHODS

Anteroposterior and lateral radiograms were performed on the sample (38 O.I. patients, of whom 19 presenting listhesis); on imaging studies spondylolisthesis was quantified according to the Meyerding classification. Genant's semiquantitative classification was applied on lateral view to evaluate the L5 fractures; skeleton spinal morphometry (MXA) was carried out on the same images to collect quantitative data comparable and superimposable to Genant's classification. The gathered information were analyzed through statistical tests (O.R., χ ² test, Fisher's test, Pearson's correlation coefficient).

RESULTS

The prevalence of L5 fractures is 73.7 % in O.I. patients with spondylolisthesis and their risk of experiencing such a fracture is twice than O.I. patients without listhesis (OR 2.04). Pearson's χ ² test demonstrates an association between L5 spondylolisthesis and L5 fracture, especially with moderate, posterior fractures (p = 0.017) and primarily in patients affected by type IV O.I.

CONCLUSIONS

Spondylolisthesis represents a risk factor for the development of more severe and biconcave/posterior type fractures of L5 in patients suffering from O.I., especially in type IV. This fits the hypothesis that the anterior sliding of the soma of L5 alters the dynamics of action of the load forces, localizing them on the central and posterior heights that become the focus of the stress due to movement of flexion-extension and twisting of the spine. As a result, there is greater probability of developing an important subsidence of the central and posterior walls of the soma.

Osteosynthesis in Osteogenesis Imperfecta, telescopic versus non-telescopic nailing

The paper refers to a pediatric patient suffering from Osteogenesis Imperfecta that was diagnosed soon after birth, after suffering from an intrauterine fracture of the femur in the 7th month of pregnancy. The beginning of the presentation contains some general considerations regarding the illness and the treatment done up to the point when the first telescopic rod was used. Following the evolution of the child from birth to the age of 7 years, we could trace a line of evolution under several methods of treatment, surgical or conservative, and also on different surgical treatment variants and their outcome during growth. Together with the X-rays that documented each step of the treatment, we could affirm for sure that both clinically and radiologically, the best results were obtained after the last 4 interventions, when all 4 major bones of the lower limbs were operated on. Until the moment Fassier-Duval nails were used, the evolution of the illness and the complications that appeared after certain surgery procedures were not so good. Several procedures had to be revised because of nail or pin displacement and eventually the patient lost the walking capability. The main problem with non telescopic treatment was the lack of stability that the bone needed to have after an open surgery for deformity correction, and up to that moment, the methods used were not designed to work on the long term; even in the best circumstances, the patient had to go to the OR for nail replacement after the bone outgrew it.

Early telescopic rod osteosynthesis for Osteogenesis Imperfecta patients

Osteogenesis imperfecta is a genetically determined pathology that implies bone variability and osteoporosis with early onset of fractures after low energy trauma. For a better understanding of the clinical problems, Sillence and Danks created a classification. The study group consisted of 12 patients both males and females, with ages ranging from 2 years and 3 months to 12 years. All of them came to the hospital late, after walking, after several fractures occurred and the only treatment they underwent was with prolonged cast immobilization that caused rapid bone demineralization, axial deformations of the affected bones, increased number of fractures and eventually loss of ambulation. Following the discharged patients, we appreciated that the open bone alignment and Fassier Duval osteosynthesis were the best way to treat a patient with Lobstein disease. The results showed that by using these two techniques a lot of time is saved on a long term because all the great complications associated with older techniques are gone and a rapid ambulation is possible due to the soft tissue damage that is kept to a minimum.

Living donor liver transplantation for an infant with osteogenesis imperfecta and intrahepatic cholestasis: report of a case

Osteogenesis imperfecta (OI) is a group of genetic disorders characterized by bone fragility and connective tissue manifestations. We report a successful liver transplantation (LT) in an 8-month-old boy with OI and cholestatic biliary cirrhosis. After 4 cycles of intravenous pamidronate, LT was performed under intravenous anesthesia using a left lateral section from his mother without mechanical retractors. The operation time was 420 min and estimated blood loss was 520 mL requiring one unit of RBC transfusion. He was discharged without surgical complications. Therefore, LT should be considered for patients with end stage liver disease and OI under organic multidisciplinary cooperation.