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Molecular Genetics & Genomic Medicine May 2024Bone tissue homeostasis relies on the coordinated activity of the bone-forming osteoblasts and bone-resorbing osteoclasts. Osteomesopyknosis is considered a distinctive...
BACKGROUND
Bone tissue homeostasis relies on the coordinated activity of the bone-forming osteoblasts and bone-resorbing osteoclasts. Osteomesopyknosis is considered a distinctive rare sclerosing skeletal disorder of unelucidated pathophysiology and presumably autosomal dominant transmission. However, the causal genes are unknown.
METHODS
We present a case report encompassing clinical assessments, imaging studies, and whole-exome sequencing analysis, complemented by functional in vitro experiments.
RESULTS
This new case of osteomesopyknosis was associated with a missense ALOX5 variant predicted to induce protein misfolding and proteasomal degradation. Transfection experiments demonstrated that the variant was associated with reduced protein levels restored by proteasomal inhibition with bortezomib. Likewise, gene expression analysis showed that the mutated gene was associated with a decreased RANKL/OPG ratio, which is a critical driver of osteoclast precursor differentiation.
CONCLUSION
Our data indicate impaired bone resorption as the underlying mechanism of this rare osteosclerosis, implicating ALOX5 pathogenic variants as potential etiological factors.
Topics: Humans; RANK Ligand; Arachidonate 5-Lipoxygenase; Mutation, Missense; Osteosclerosis; Male; Female; Osteoclasts; Signal Transduction
PubMed: 38803233
DOI: 10.1002/mgg3.2471 -
Journal of Clinical Medicine Apr 2024: Pycnodysostosis is a rare genetic disorder causing skeletal dysplasia. It is determined by a gene mutation leading to cathepsin K deficiency and predisposes a patient...
: Pycnodysostosis is a rare genetic disorder causing skeletal dysplasia. It is determined by a gene mutation leading to cathepsin K deficiency and predisposes a patient to osteosclerosis, resulting in increased bone fragility. The altered bone quality typical of this disease is responsible for an increased risk of fractures. The purpose of our study was to evaluate the orthopedic manifestations and potential pitfalls in the surgical treatments of pathological fractures in a series of patients treated in our institution who were affected by pycnodysostosis. : We retrospectively evaluated clinical and radiographic characteristics of five patients with pycnodysostosis treated for pathological fractures at our hospital in the past 5 years. : Two male and three female patients were included in this study. Four patients had a family history of pycnodysostosis. All the patients were of short stature, but only two underwent growth hormone treatment. All the patients experienced fractures, mostly in their lower limbs and occurring as a result of low-energy trauma. Most of the patients experienced either consolidation delay or nonunion. : The orthopedic management of fractures in patients with pycnodysostosis poses an ongoing challenge for orthopedic surgeons. The fact that the bone is simultaneously sclerotic and brittle makes any orthopedic surgical treatment challenging and at a high risk of nonunion in any case.
PubMed: 38731051
DOI: 10.3390/jcm13092522 -
Scientific Reports Apr 2024Raine syndrome (RNS) is a rare autosomal recessive osteosclerotic dysplasia. RNS is caused by loss-of-function disease-causative variants of the FAM20C gene that encodes...
Raine syndrome (RNS) is a rare autosomal recessive osteosclerotic dysplasia. RNS is caused by loss-of-function disease-causative variants of the FAM20C gene that encodes a kinase that phosphorylates most of the secreted proteins found in the body fluids and extracellular matrix. The most common RNS clinical features are generalized osteosclerosis, facial dysmorphism, intracerebral calcifications and respiratory defects. In non-lethal RNS forms, oral traits include a well-studied hypoplastic amelogenesis imperfecta (AI) and a much less characterized gingival phenotype. We used immunomorphological, biochemical, and siRNA approaches to analyze gingival tissues and primary cultures of gingival fibroblasts of two unrelated, previously reported RNS patients. We showed that fibrosis, pathological gingival calcifications and increased expression of various profibrotic and pro-osteogenic proteins such as POSTN, SPARC and VIM were common findings. Proteomic analysis of differentially expressed proteins demonstrated that proteins involved in extracellular matrix (ECM) regulation and related to the TGFβ/SMAD signaling pathway were increased. Functional analyses confirmed the upregulation of TGFβ/SMAD signaling and subsequently uncovered the involvement of two closely related transcription cofactors important in fibrogenesis, Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ). Knocking down of FAM20C confirmed the TGFβ-YAP/TAZ interplay indicating that a profibrotic loop enabled gingival fibrosis in RNS patients. In summary, our in vivo and in vitro data provide a detailed description of the RNS gingival phenotype. They show that gingival fibrosis and calcifications are associated with, and most likely caused by excessed ECM production and disorganization. They furthermore uncover the contribution of increased TGFβ-YAP/TAZ signaling in the pathogenesis of the gingival fibrosis.
Topics: Humans; Transforming Growth Factor beta; Gingiva; Signal Transduction; Proteomics; Fibrosis; YAP-Signaling Proteins; Osteosclerosis; Adaptor Proteins, Signal Transducing; Transcription Factors; Dental Enamel Hypoplasia; Fibroblasts; Microcephaly; Female; Transcriptional Coactivator with PDZ-Binding Motif Proteins; Male; Trans-Activators; Intracellular Signaling Peptides and Proteins; Casein Kinase I; Extracellular Matrix Proteins; Amelogenesis Imperfecta; Cells, Cultured; Abnormalities, Multiple; Cleft Palate; Exophthalmos
PubMed: 38664418
DOI: 10.1038/s41598-024-59713-0 -
Frontiers in Endocrinology 2024Congenital Generalized Lipodystrophy (CGL) is a rare autosomal recessive disease caused by mutations in genes responsible for the formation and development of...
INTRODUCTION
Congenital Generalized Lipodystrophy (CGL) is a rare autosomal recessive disease caused by mutations in genes responsible for the formation and development of adipocytes. Bone abnormalities are described. However, there is a scarcity of data.
OBJECTIVE
To describe bone characteristics in a large CGL1 and 2 case series.
METHODS
Cross-sectional study that assessed bone radiological features of CGL patients of a reference hospital in Fortaleza (CE), Brazil. Patients underwent clinical and bone mineral metabolism evaluation, radiographs of the axial and appendicular skeleton and bone mineral density (BMD) assessment by DEXA (dual energy X-ray absorptiometry).
RESULTS
Nineteen patients were included, fourteen were CGL1 and 5, CGL2. Median age was 20 years (8-42) and 58% were women. Median BMI and percentage of body fat were, respectively, 21 Kg/m² (16-24), and 10.5% (7.6-15). The median leptin concentration was 1 ng/mL (0.1-3.3). Diabetes mellitus and dyslipidemia were present in 79% and 63% of patients, respectively. Median calcium and phosphate were normal in almost all patients (95%). Median parathyroid hormone and 25-OH-vitamin D were 23 pg/mL (7-75) and 28 ng/mL (18-43). Osteolytic lesions, osteosclerosis and pseudo-osteopoikylosis, were present in 74%, 42% and 32% of patients, respectively. Lytic lesions were found predominantly in the extremities of long bones, bilaterally and symmetrically, spine was spared. Osteosclerosis was present in axial and appendicular skeleton. Pseudo-osteopoikilosis was found symmetrically in epiphyses of femur and humerus, in addition to the pelvis. BMD Z-score greater than +2.5 SD was observed in 13 patients (68.4%). BMD was higher in CGL1 compared to CGL2 in lumbar spine and total body in adults. No associations were found between high BMD and HOMA-IR (p=0.686), DM (p=0.750), osteosclerosis (p=0.127) or pseudo-osteopoikilosis (p=0.342), and, between pain and bone lesions. Fractures were found in 3 patients.
CONCLUSION
Bone manifestations are prevalent, heterogeneous, and silent in CGL1 and CGL2. Osteolytic lesions are the most common, followed by osteosclerosis and pseudo-osteopoikilosis. Bone mass is high in most cases. There was no pain complaint related to bone lesions. Thus, systematic assessment of bone manifestations in CGL is essential. Studies are needed to better understand its pathogenesis and clinical consequences.
Topics: Adult; Humans; Female; Young Adult; Male; Bone Density; Lipodystrophy, Congenital Generalized; Osteopoikilosis; Prevalence; Cross-Sectional Studies; Lumbar Vertebrae; Osteosclerosis; Bone Diseases
PubMed: 38633760
DOI: 10.3389/fendo.2024.1326700 -
Cureus Mar 2024Numb chin syndrome (NCS) is hypesthesia of the mandible and lower lip caused by damage to the inferior alveolar or mandibular nerves, commonly due to dental treatment or...
Numb chin syndrome (NCS) is hypesthesia of the mandible and lower lip caused by damage to the inferior alveolar or mandibular nerves, commonly due to dental treatment or osteomyelitis, but occasionally caused by malignant tumors. We report the case of a male in his 60s. He came to our hospital with a chief complaint of mandibular pain and paresthesia in the right side of the mental region. He had noticed swelling of the left mandible one month before the initial visit and strong hypesthesia of the right side of the mental region one week before the initial visit. Panoramic radiographs showed slight osteosclerosis of the left side mandible at the initial visit. Blood tests showed only a slight inflammatory reaction. The diagnosis of mandibular osteomyelitis and numb chin syndrome was made, and a contrast-enhanced CT scan was performed to investigate the possibility of neoplastic lesions, but no obvious cause was found. Osteosclerosis was minimal. A tissue biopsy was recommended, but the patient did not consent. Considering the possibility of NCS due to a hematologic disorder, the patient was referred to a hematologist, but no cause could be identified at the initial visit. With time, the markedly severe pain worsened, and the possibility of a neoplastic lesion was again suspected. Blood tests were performed, which revealed abnormally high levels of CA19 and CEA. He consulted a gastroenterologist, who found a tumor in the ileocecal region on contrast-enhanced CT, and multiple systemic metastases were found on a PET-CT scan the next day. Systemic chemotherapy was administered for multiple metastatic unresectable colorectal cancer (cT4N1aMc2 stage IVc).
PubMed: 38618368
DOI: 10.7759/cureus.56133 -
JBMR Plus May 2024Skeletal fluorosis is rare and occurs secondary to chronic high amounts of fluoride consumption, manifesting as diffuse osteosclerosis, skeletal pain, connective tissue...
UNLABELLED
Skeletal fluorosis is rare and occurs secondary to chronic high amounts of fluoride consumption, manifesting as diffuse osteosclerosis, skeletal pain, connective tissue calcification, and increased fracture risk. Methoxyflurane is a volatile, fluorinated hydrocarbon-inhaled analgesic, and the maximum recommended dose is 15 mL (99.9 % w/w) per wk. A rodent study found increased skeletal fluoride after methoxyflurane exposure. However, skeletal fluorosis secondary to methoxyflurane use in humans has rarely been reported. We present the case of a 47-yr-old female with diffuse osteosclerosis secondary to fluorosis from methoxyflurane use for chronic pain, presenting with 3 yr of generalized bony pain and multiple fragility fractures. Lumbar spine BMD was elevated. CT and radiographs demonstrated new-onset marked diffuse osteosclerosis, with calcification of interosseous membranes and ligaments, and a bone scan demonstrated a grossly increased uptake throughout the skeleton. Biochemistry revealed an elevated alkaline phosphatase and bone turnover markers, mild secondary hyperparathyroidism with vitamin D deficiency, and mild renal impairment. Zoledronic acid, prescribed for presumed Paget's disease, severely exacerbated bony pain. Urinary fluoride was elevated (7.3 mg/L; reference range < 3.0 mg/L) and the patient revealed using methoxyflurane 9 mL per wk for 8 yr for chronic pain. A decalcified bone biopsy revealed haphazardly arranged cement lines and osteocytes lacunae and canaliculi, which was consistent with an osteosclerotic process. Focal subtle basophilic stippling around osteocyte lacunae was suggestive of fluorosis. Although fluorosis is not a histological diagnosis, the presence of compatible histology features was supportive of the diagnosis in this case with clinical-radiological-pathological correlation. Skeletal fluorosis should be considered as a cause of acquired diffuse osteosclerosis. Methoxyflurane should not be recommended for chronic pain. The risk of repeated low-dose exposure to fluoride from methoxyflurane use as analgesia may be greater than expected, and the maximum recommended dose for methoxyflurane may require re-evaluation to minimize skeletal complications.
ABBREVIATED ABSTRACT
Skeletal fluorosis is rare and occurs secondary to chronic high amounts of fluoride consumption, manifesting as diffuse osteosclerosis, skeletal pain, connective tissue calcification, and increased fracture risk. We present the case of a 47-yr-old female with skeletal fluorosis secondary to long-term methoxyflurane for chronic pain. The risk of repeated low-dose exposure to fluoride from methoxyflurane use for analgesia may be greater than expected, and the maximum recommended dose for methoxyflurane may require re-evaluation to minimize skeletal complications.
PubMed: 38577522
DOI: 10.1093/jbmrpl/ziae032 -
Journal of Bone Oncology Apr 2024Osteosclerosis in multiple myeloma (MM) is typically associated with rare POEMS syndrome, characterized by polyneuropathy (P), organomegaly (O), endocrinopathy (E),... (Review)
Review
Osteosclerosis in multiple myeloma (MM) is typically associated with rare POEMS syndrome, characterized by polyneuropathy (P), organomegaly (O), endocrinopathy (E), M-protein (M), and skin changes (S). However, osteosclerosis in multiple myeloma (MM) without POEMS syndrome, defined as non-POEMS Osteosclerotic MM, is exceedingly rare. We report a 70-year-old man with rib pain, remarkably high bone mineral density and diffuse osteosclerosis. The diagnosis of non-POEMS osteosclerotic MM was confirmed by biopsy and aspiration of bone marrow through surgery. A literature review spanning from 1990 identified 12 cases of similar non-POEMS osteosclerotic MM, including 5 males and 7 females with a mean age of 59.7 ± 10.6 years. The non-POEMS osteosclerotic MM can be divided into two subtypes, the osteosclerotic lesion subtype and the diffuse osteosclerosis subtype. Absence of polyneuropathy and organomegaly are the main factors that differentiate non-POEMS osteosclerotic MM from POEMS. A hyperactive osteoblastic process might be the etiology of diffuse osteosclerosis. Further research is needed to understand its etiology and pathophysiology.
PubMed: 38572352
DOI: 10.1016/j.jbo.2024.100595 -
Reumatismo Mar 2024Melorheostosis is a rare, non-hereditary, benign bone disease characterized by abnormal bone growth. Generally, melorheostosis develops during childhood or adolescence... (Review)
Review
OBJECTIVE
Melorheostosis is a rare, non-hereditary, benign bone disease characterized by abnormal bone growth. Generally, melorheostosis develops during childhood or adolescence and progresses gradually over time. This disease represents a true challenge to the physician because of its variability due to location, extension of the affected bone, and involvement of associated soft tissue. Pain management, physical therapy, and surgery may be recommended, depending on the individual case. This review aims to get an overview of the latest evidence relating to epidemiology, clinical and radiographic characteristics, diagnosis, and possible therapeutic strategies for melorheostosis and describe our experience through a clinical case.
METHODS
We designed a comprehensive literature search on melorheostosis in MEDLINE (via Pubmed) up to April 2023 and reviewed reports published in international journals.
RESULTS
The purpose is to highlight the importance of a multidisciplinary approach in the management of a rare disease such as melorheostosis. We discuss the role of different physicians, including genetists, rheumatologists, physiatrists, physical therapists, and orthopedic surgeons, in providing accurate diagnoses and effective treatments. We conducted a comprehensive review of the literature on the treatment of melorheostosis to support these findings. In addition, the article presents a case study of a patient suffering from melorheostosis, focusing on difficulties in reaching a correct diagnosis and attempts towards conservative and surgical interventions. The patient underwent hip arthroplasty, and the final result was an improvement in function and a reduction in pain.
CONCLUSIONS
Managing melorheostosis can be challenging, and there is no standardized treatment for this condition at the moment.
Topics: Adolescent; Humans; Melorheostosis; Pain; Pain Management; Treatment Outcome; Rare Diseases
PubMed: 38523583
DOI: 10.4081/reumatismo.2024.1621 -
International Journal of Surgery Case... Apr 2024Osteopetrosis is a rare hereditary disease that can be transmitted in an autosomal recessive or autosomal dominant.
INTRODUCTION
Osteopetrosis is a rare hereditary disease that can be transmitted in an autosomal recessive or autosomal dominant.
CASE REPORT
Here, we report a case of trochanteric fracture in an 18-year-old boy with an anatomical plate. At the last follow-up, 24 months after surgery, the fracture had healed well, and the patient was not restricted in his activities.
DISCUSSION
Osteopetrosis is a rare bone disease that is mainly caused by osteoclast dysfunction. It results from a remodelling defect that leads to hypermineralization of the skeleton, resulting in bone fragility. Both surgical and nonsurgical management have advantages and disadvantages. Thus, open reduction and anatomic plate fixation remain effective management modalities for trochanteric fractures in osteopetrosis patients.
CONCLUSION
For our patient and as described in the literature, the complication rate decreases as some principles are respected with better consolidation of the osteoporotic fracture.
PubMed: 38513419
DOI: 10.1016/j.ijscr.2024.109568 -
Cureus Feb 2024Idiopathic osteosclerosis (IO) is described as a localized radiopacity of unknown etiology. Also known as dense bone islands, enostoses, bone scar, or focal periapical...
Idiopathic osteosclerosis (IO) is described as a localized radiopacity of unknown etiology. Also known as dense bone islands, enostoses, bone scar, or focal periapical osteopetrosis, it is generally clinically asymptomatic and appears round, elliptical, or irregular in shape on a radiograph. The internal structure is usually homogenous. It should be distinguished from condensing osteitis and other alveolar bone-related radiopacities. This condition may cause changes in tooth position or interfere with orthodontic treatment. Two cases of IO involving the maxilla and mandible are highlighted. Both patients were females and presented with complaints of malocclusion and desired orthodontic correction. One case was detected incidentally on routine radiographic examination of the patient. In contrast, the other case presented as an expansile lesion lingual to the left mandibular first molar and second premolar. Radiographically, both lesions appeared as well-defined radiopaque masses with no surrounding radiolucent rim; the maxillary lesion was irregular in shape, while the mandibular lesion was elliptical. Both patients underwent orthodontic treatment without any adverse sequelae. The clinical and radiographic findings are discussed to facilitate the diagnosis of radiopacities of jaws. Usually asymptomatic and of no clinical significance, IO may occasionally induce root resorption, traumatic occlusion, traumatic/pathologic migration of teeth, and inhibit eruption of teeth. Though orthodontic tooth movement through areas of IO can be undertaken, the rate of tooth movement may be slower due to higher trabecular bone density. Lower force levels are warranted to avoid adverse effects like root resorption and bone hyalinization.
PubMed: 38435170
DOI: 10.7759/cureus.53426