Cherubism: best clinical practice

Tankyrase (PARP5) Inhibition Induces Bone Loss through Accumulation of Its Substrate SH3BP2

There is considerable interest in tankyrase because of its potential use in cancer therapy. Tankyrase catalyzes the ADP-ribosylation of a variety of target proteins and regulates various cellular processes. The anti-cancer effects of tankyrase inhibitors are mainly due to their suppression of Wnt signaling and inhibition of telomerase activity, which are mediated by AXIN and TRF1 stabilization, respectively. In this review, we describe the underappreciated effects of another substrate, SH3 domain-binding protein 2 (SH3BP2). Specifically, SH3BP2 is an adaptor protein that regulates intracellular signaling pathways. Additionally, in the human genetic disorder cherubism, the gain-of-function mutations in SH3BP2 enhance osteoclastogenesis. The pharmacological inhibition of tankyrase in mice induces bone loss through the accumulation of SH3BP2 and the subsequent increase in osteoclast formation. These findings reveal the novel functions of tankyrase influencing bone homeostasis, and imply that tankyrase inhibitor treatments in a clinical setting may be associated with adverse effects on bone mass.

A Paradigm Shift in the Management of Cherubism? A Preliminary Report Using Imatinib

Cherubism is an autosomal-dominant inherited mutation in the SH3BP2 gene on chromosome 4p16.3. It is characterized by bilateral symmetric fibro-osseous lesions that are limited to the maxilla and mandible. The lesions present in early childhood and typically spontaneously involute after puberty. Current standard practice is to reserve surgery for symptomatic or severely disfiguring cases. This report presents 3 patients with cherubism who exhibited marked reduction in tumor size with imatinib, a tyrosine kinase inhibitor. Treatment was well tolerated, with few side effects.

Surgical congenital anomalies in Albania: incidence, prenatal diagnosis and outcome

Introduction

Significant progress has been made in the diagnosis and management of congenital anomalies (CA). In our study, we aimed to evaluate prenatal diagnosis, trend of surgical CA, mortality rate and the factors affecting their prognosis in our country.

Methods

We enrolled in our study all children with CA who underwent surgery from January 2008 to December 2017. We compared prenatal diagnosis, incidence and mortality for two 5-year periods: the first period in 2008–2012 and the second period in 2013–2017.

Results

During the study period, a total of 321 cases with CA were presented, with an incidence of 0.69–1.18 per 1000 live births. Intestinal, anal and esophageal atresia remain the most important CAs (23%, 18% and 16%), followed by diaphragmatic hernia and gastroschisis (10% and 7%). Comparing the incidence for the two periods, we did not find statistical differences (p=0.73), but the mortality rate has been reduced from 31.4% during the first period to 24.6% during the second period (p=0.17). Prenatal diagnosis has increased: 28% in the second period compared with 10% in the first period (p<0.001), without significantly affecting the prognosis (p=0.09). Birth of premature babies resulted in a significantly negative predictive factor for the prognosis of these anomalies (p=0.0002).

Conclusion

Incidence of CA has not changed over the years in our country. Advances in intensive care, surgical techniques and parenteral nutrition made in recent years have significantly increased the survival of neonates born with surgical CA. Birth of premature babies was a significantly negative predictive factor for the prognosis of these anomalies.

Ramon Syndrome- A Rare Form of Cherubism

Cherubism is an inherited, autosomal dominant disorder that affects the jaws of children. The disease is usually obvious as a painless bilateral swelling in which bone is replaced with fibrous tissue. Affected children appear normal at birth. Swelling of the jaws usually occurs between 2 and 7 years of age and relapses as age progresses leaving a few facial deformities and malocclusion. The disease is microscopically indistinguishable from other giant cell lesions. The association of cherubism with gingival fibromatosis, epilepsy, mental retardation, stunted growth, and hypertrichosis is referred to as a rare case of possible Ramon syndrome with extraordinary tissue enlargement over the teeth. Here, we present a case of Ramon syndrome in a 6-year-old girl describing the clinical and radiographic features successfully treated with a brief review of literature.

Early detection of cherubism with eventual bilateral progression: a literature review and case report

Cherubism is a rare familial disease of childhood that commonly affects the bilateral mandible and maxilla and typically resolves in adulthood. It has been shown to have a male predilection and has been mapped to the SH3 BP2 gene. Only 2 cases of unilateral cherubism have been documented in the literature; in the first case, the contralateral side was eventually affected. Although rare, unilateral cherubism presents a diagnostic dilemma. This case report describes a unique presentation of unilateral cherubism that progressed to affect the contralateral side and describes some of the considerations in the diagnosis and treatment of unilateral benign giant cell lesions of the jaws.

Bilateral Central Giant Cell Granuloma of the mandibular angle in three females from the same family

In literature there are few reports about multiple CGCG. But this is the first report of bilateral CGCG of the mandibular angles in three females from the same family.This report describes three cases of females from the same family - a mother and two young daughters - with bilateral CGCG in their jaw angles. All the lesions were surgically removed and the histopathologic diagnosis was always identical: giant cell central granulomas, with patterns that were absolutely superimposable between them and with that of the mother.The hypothesis is that this presentation of CGCG may be defined as hereditary bilateral CGCG of the mandibular angles (or also, cherubism-like lesions).

Rescue of a cherubism bone marrow stromal culture phenotype by reducing TGFβ signaling

We utilized a bone marrow stromal culture system to investigate changes in TGFβ signaling in a mouse model for cherubism (Sh3bp2^KI/KI). Interestingly, bone marrow cultures derived from cherubism mice not only displayed impaired osteoblast differentiation, but also had spontaneous osteoclast formation. PAI1, a target gene of TGFβ signaling, was elevated 2-fold in cherubism CD11b^-,CD45^- cells compared to wild type cells, while the expression of BAMBI, an inhibitor of TGFβ signaling, was down-regulated. We also discovered that treatment of cherubism cultures with antagonists of the TGFβ signaling pathway could largely rescue osteoblast differentiation and markedly reduce spontaneous osteoclast formation. Treatment with the type I TGFβ receptor small molecule inhibitor SB505124 increased osteoblast reporter gene Col1a1-2.3 expression 24-fold and increased the expression of osteoblast gene markers Osterix (Sp7) 25-fold, Bone Sialoprotein (BSP) 7-fold, Osteocalcin (Bglap1) 100-fold, and Dentin Matrix Protein 1 (DMP1) 35-fold. In contrast, SB505124 treatment resulted in a significant reductions in osteoclast number and size. Gene expression analyses for RANKL, a positive regulator of osteoclast formation was 2.5-fold higher in osteoblast cultures derived from Sh3bp2^KI/KI mice compared to wild type cultures, whereas OPG, an inhibitor of RANKL was 5-fold lower. However, SB505124 treatment reduced RANKL almost back down to wild type levels, while increasing OPG expression. Our studies also implicate a role for TGFβ ligands in the etiology of cherubism. Blocking of TGFβ ligands with the monoclonal antibody 1D11 increased Col1a1-2.3 reporter expression 4-fold and 13-fold in cultures derived from Sh3bp2^KI/+ and Sh3bp2^KI/KI mice, respectively. Serum levels of latent TGFβ1 were also 2-fold higher in SH3BP2^KI/KI mice compared to wild type littermates. Taken together, these studies provide evidence that elevated levels of TGFβ signaling may contribute to the disease phenotype of cherubism and a reduction in pathway activity may be an effective therapeutic approach to treat this rare disease.

Innovative Surgical Treatment of Severe Cherubism

Background:

Cherubism is an autosomal dominant syndrome characterized by excessive bilateral maxillomandibular bony degeneration and fibrous tissue hyperplasia. Conservative management is the preferred treatment as cherubism has a self-limiting course. Functional or emotional disturbances may, however, demand surgical intervention. We report a patient who underwent surgical intervention.

Method/Description:

He had significant enlargement of lower cheeks and bilateral lower lid scleral show. On computed tomography of the face, the patient had significant fibrous tissue involving bilateral maxilla and mandible. The mandibular tumor was excised. Given normal inferior border, bilateral sagittal split osteotomy was performed to infracture and inset the outer cortex. During the procedure, patient required blood transfusion intraoperatively, so the maxillary portion of the procedure was delayed until 6 months later. For the maxilla, bilateral transconjunctival approach was used to resect parts of the orbital floors that were concave, resulting in 1 × 2 cm defects bilaterally which were reconstructed using resorbable plates. Then the anterior maxillary tumor was excised.

Results:

The patient and his parents were satisfied with his appearance after surgery. The patient was noted to have improvement in contour and decreased scleral show. He has most recently followed up 15 months after the initial surgery. There were no long-term complications.

Conclusions:

Severity of cherubism influences the type of surgical intervention. The present case is innovative because this is the first reported case of recontouring orbital floors with resorbable plates and infracturing of the mandible using sagittal split osteotomies for surgical treatment of cherubism.

Gnathodiaphyseal dysplasia: Severe atypical presentation with novel heterozygous mutation of the anoctamin gene (ANO5)

Gnathodiaphyseal dysplasia (GDD; OMIM #166260) is an ultra-rare autosomal dominant disorder caused by heterozygous mutation in the anoctamin 5 (ANO5) gene and features fibro-osseous lesions of the jawbones, bone fragility with recurrent fractures, and bowing/sclerosis of tubular bones. The physiologic role of ANO5 is unknown. We report a 5-year-old boy with a seemingly atypical and especially severe presentation of GDD and unique ANO5 mutation. Severe osteopenia was associated with prenatal femoral fractures, recurrent postnatal fractures, and progressive bilateral enlargement of his maxilla and mandible beginning at ~2months-of-age that interfered with feeding and speech and required four debulking operations. Histopathological analysis revealed benign fibro-osseous lesions resembling cemento-ossifying fibromas of the jaw without psammomatoid bodies. A novel, de novo, heterozygous, missense mutation was identified in exon 15 of ANO5 (c.1553G>A; p.Gly518Glu). Our findings broaden the phenotypic and molecular spectra of GDD. Fractures early in life with progressive facial swelling are key features. We assessed his response to a total of 7 pamidronate infusions commencing at age 15months. Additional reports must further elucidate the phenotype, explore any genotype-phenotype correlation, and evaluate treatments.

Pharmacological inhibition of tankyrase induces bone loss in mice by increasing osteoclastogenesis

Tankyrase is a poly (ADP-ribose) polymerase that leads to ubiquitination and degradation of target proteins. Since tankyrase inhibitors suppress the degradation of AXIN protein, a negative regulator of the canonical Wnt pathway, they effectively act as Wnt inhibitors. Small molecule tankyrase inhibitors are being investigated as drug candidates for cancer and fibrotic diseases, in which the Wnt pathways are aberrantly activated. Tankyrase is also reported to degrade the adaptor protein SH3BP2 (SH3 domain-binding protein 2). We have previously shown that SH3BP2 gain-of-function mutation enhances receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis in murine bone marrow-derived macrophages (BMMs). Although the interaction between tankyrase and SH3BP2 has been reported, it is not clear whether and how the inhibition of tankyrase affects bone cells and bone mass. Here, we have demonstrated that tankyrase inhibitors (IWR-1, XAV939, and G007-LK) enhanced RANKL-induced osteoclast formation and function in murine BMMs and human peripheral blood mononuclear cells through the accumulation of SH3BP2, subsequent phosphorylation of SYK, and nuclear translocation of NFATc1. Tankyrase inhibitors also enhanced osteoblast differentiation and maturation, represented by increased expression of osteoblast-associated genes accompanied by the accumulation of SH3BP2 protein and enhanced nuclear translocation of ABL, TAZ, and Runx2 in primary osteoblasts. Most importantly, pharmacological inhibition of tankyrase in mice significantly decreased tibia and lumbar vertebrae bone volumes in association with increased numbers of osteoclasts. Our findings uncover the role of tankyrase inhibition in bone cells and highlight the potential adverse effects of the inhibitor on bone.

Dealing with Chronic Non-Bacterial Osteomyelitis: a practical approach

BACKGROUND

Chronic Non-Bacterial Osteomyelitis (CNO) is an inflammatory disorder that primarily affects children. Although underestimated, its incidence is rare. For these reasons, no diagnostic and no therapeutic guidelines exist. The manuscript wants to give some suggestions on how to deal with these patients in the every-day clinical practice.

MAIN BODY

CNO is characterized by insidious onset of bone pain with local swelling. Systemic symptoms such as fever, skin involvement and arthritis may be sometimes present. Radiological findings are suggestive for osteomyelitis, in particular if multiple sites are involved. CNO predominantly affects metaphyses of long bones, but clavicle and mandible, even if rare localizations of the disease, are very consistent with CNO diagnosis. CNO pathogenesis is still unknown, but recent findings highlighted the crucial role of cytokines such as IL-1β and IL-10 in disease pathogenesis. Moreover, the presence of non-bacterial osteomyelitis among autoinflammatory syndromes suggests that CNO could be considered an autoinflammatory disease itself. Differential diagnosis includes infections, malignancies, benign bone tumors, metabolic disorders and other autoinflammatory disorders. Radiologic findings, either with Magnetic Resonance or with Computer Scan, may be very suggestive. For this reason in patients in good clinical conditions, with multifocal localization and very consistent radiological findings bone biopsy could be avoided. Non-Steroidal Anti-Inflammatory Drugs are the first-choice treatment. Corticosteroids, methotrexate, bisphosphonates, TNFα-inhibitors and IL-1 blockers have also been used with some benefit; but the choice of the second line treatment depends on bone lesions localizations, presence of systemic features and patients' clinical conditions.

CONCLUSION

CNO may be difficult to identify and no consensus exist on diagnosis and treatment. Multifocal bone lesions with characteristic radiological findings are very suggestive of CNO. No data exist on best treatment option after Non-Steroidal Anti-Inflammatory Drugs failure.

Bone-Related Lesions of the Jaws

The jaws combine several unique properties that mainly result from their distinct embryonic development and their role in providing anchorage for the teeth and their supporting structures. As a consequence, several bone-related lesions almost exclusively develop in the jaws (eg, osseous dysplasias, ossifying fibromas), have distinct clinical features (eg, osteosarcoma), or hardly ever occur at this location (eg, osteochondroma, enchondroma). The specific characteristics of these tumors and tumorlike lesions are outlined in this article.

Clinicopathologic and Molecular Characteristics of Familial Cherubism with Associated Odontogenic Tumorous Proliferations

Cherubism is a rare autosomal dominant condition affecting the jaws and caused by mutations in the gene encoding for the adapter protein SH3BP2 that maps to chromosome 4p16.3. Cherubism is characterized by symmetrically developing bone lesions in the maxilla and mandible. The lesions have been radiographically and histopathologically well-described. Here, we present a family with cherubism with two of its members featuring odontogenic tumorous proliferations in association with persistent central giant cell lesions (CGCL). Specifically, the proband, a 25-year-old male, developed a radiolucent lesion characterized histologically by central odontogenic fibroma-like proliferation in association with a CGCL component, while his mother, at age 57, was diagnosed with primary intraosseous odontogenic carcinoma with areas of benign fibro-osseous lesions. In both patients the lesions occurred in the anterior mandible and presented with clinical enlargement. The son underwent incisional biopsy and did not have additional treatment. His mother underwent extensive mandibulectomy due to widespread tumor. The son has two affected children with classic cherubism while a third child at age 5, had not shown any features of the disease. Mutation analysis of three affected members resulted in the identification of a heterozygous mutation in SH3BP2 (c.1244G>C; p.Arg415Pro). To the best of our knowledge, association of cherubism with odontogenic neoplastic lesions has hitherto not been reported in the literature, thus suggesting a relationship between cherubism with disturbed odontogenesis.

An Update on the Pathogenesis and Treatment of Chronic Recurrent Multifocal Osteomyelitis in Children

Chronic recurrent multifocal osteomyelitis (CRMO), also known as chronic non-bacterial osteomyelitis (CNO), is a rare inflammatory disorder that primarily affects children. It is characterized by pain, local bone expansion, and radiological findings suggestive of osteomyelitis, usually at multiple sites. CRMO predominantly affects the metaphyses of long bones, but involvement of the clavicle or mandible are suggestive of the diagnosis. CRMO is a diagnosis of exclusion, and its pathogenesis remains unknown. Differential diagnosis includes infection, malignancies, benign bone tumors, metabolic disorders, and other autoinflammatory disorders. Biopsy of the bone lesion is not often required but could be necessary in unclear cases, especially for differentiation from bone neoplasia. Non-steroidal anti-inflammatory drugs (NSAIDs) are the first-line treatment. Alternative therapies have been used, including corticosteroids, methotrexate, bisphosphonates, and tumor necrosis factor (TNF)-α inhibitors. No guidelines have been established regarding diagnosis and treatment options. This manuscript gives an overview of the most recent findings on the pathogenesis of CRMO and clinical approaches for patients with the condition.

Nonfamilial cherubism: A case report and review of literature

Cherubism is a rare hereditary developmental condition of the jaws and generally inherited as an autosomal dominant trait. It is also known as familial fibrous dysplasia of the jaws, familial multilocular cystic disease and hereditary fibrous dysplasia of the jaws. The gene for cherubism is mapped to chromosome 4p16.3 may lead to pathologic activation of osteoclasts and disruption of jaw morphogenesis. The lesion usually appears between 2 and 5 years shows a predilection for the mandible and causes a bilateral swelling giving rise to a cherubic chubby appearance. The eosinophilic cuffing of blood vessels appears to be specific for cherubism. The diagnosis is based on clinical, radiographic and histopathologic findings. The purpose of this article is to present a rare case of nonfamilial cherubism as there are very few cases reported and to review the literature with its cone beam computed tomography findings.

Cherubism: A case report

Cherubism is rarely described in the African paediatric population. Orphanet currently lists cherubism as a rare disease; its prevalence is unknown and difficult to determine because of the wide clinical spectrum. Approximately 300 cases have been reported in various ethnic groups worldwide. This report analyses a child referred to our hospital for bilateral jaw swelling, diagnosed with cherubism based on clinical and radiological findings, and confirmed on histology.

Defining a new aggressiveness classification and using NFATc1 localization as a prognostic factor in cherubism

Cherubism is a rare genetic disease characterized by bilateral giant cell reparative granuloma of the jaws consisting of a fibrotic stroma with giant multinucleated cells (GMCs) and osteoclastic features. Cherubism severity is highly variable, and recurrence after surgery is the most important risk. Currently, there are no prognostic indicators. The aims of this study were to evaluate the osteoclastogenesis phenotype by histologic examination of nuclear factor of activated T cells 1 (NFATc1) localization and tartrate-resistant acid phosphatase (TRAP) activity and to correlate the results to disease aggressiveness to define prognostic indicators. Based on cherubism evolution 1 year after surgery, 3 classes of cherubism aggressiveness were identified: mild (group A), moderate (group B), and severe (group C). Histologically, in grade A and B cherubism lesions, GMCs were negative for both TRAP activity and NFATc1 nuclear localization. In contrast, in grade C cherubism lesions, GMCs were all positive for TRAP activity and NFATc1 nuclear localization and displayed osteoclast-like features. Other histopathologic findings were not different among the 3 groups. Our results establish that TRAP activity and NFTAc1 nuclear localization are associated with aggressive cherubism and therefore could be added to routine pathologic examination to aid in prognosis and management of the disease. The finding of NFATc1 nuclear localization in aggressive tumors supports the addition of anticalcineurin treatment to the therapeutic arsenal for cherubism.

Modeling craniofacial and skeletal congenital birth defects to advance therapies

Craniofacial development is an intricate process of patterning, morphogenesis, and growth that involves many tissues within the developing embryo. Genetic misregulation of these processes leads to craniofacial malformations, which comprise over one-third of all congenital birth defects. Significant advances have been made in the clinical management of craniofacial disorders, but currently very few treatments specifically target the underlying molecular causes. Here, we review recent studies in which modeling of craniofacial disorders in primary patient cells, patient-derived induced pluripotent stem cells (iPSCs), and mice have enhanced our understanding of the etiology and pathophysiology of these disorders while also advancing therapeutic avenues for their prevention.

Cherubism: An Unusual Study With Long-Term Follow-Up

Cherubism is an uncommon hereditary benign fibro-osseous disorder characterized by bilateral enlargement of the mandible and the maxilla that presents with varying degrees of involvement and a tendency toward spontaneous remission.The first visit was in 2002. A 16-year-old female was referred to an orthodontist for correction of her dental crowding. In the radiographic examination that was taken for her treatment the first time in 2002, a jaw bone lesion was discovered accidentally. X-ray panoramic imaging revealed well-defined multilocular radiolucencies involving the posterior body of the mandible and ascending rami with displaced teeth. This lesion had no effect on inferior alveolar canal and maxilla.There was no significant past medical history, and there was no family history suggestive of a similar complaint. On extraoral examination, there was no swelling in both rami of the mandible and face. Histopathological examination of the biopsy specimen showed proliferating fibrous connective tissue interspersed by multinucleated giant cells. It was diagnosed as a case nonfamilial cherubism. An extensive long-term follow-up till 12 years was maintained. In 2014, after 12-years follow-up for this lesion, panoramic imaging examination showed progress of this lesion in mandible and maxilla.

Genetically defined autoinflammatory diseases

Autoinflammatory diseases are hyperinflammatory, immune dysregulatory conditions that typically present in early childhood with fever and rashes and disease-specific patterns of organ inflammation. This review provides a historic background of autoinflammatory disease research, an overview of the currently genetically defined autoinflammatory diseases, and insights into treatment strategies derived from understanding of the disease pathogenesis. The integrative assessment of autoinflammatory conditions led to the identification of innate pro-inflammatory cytokine 'amplification loops' as the cause of the systemic and organ-specific disease manifestations, which initially centered around increased IL-1 production and signaling. More recently, additional innate pro-inflammatory cytokine amplification loops resulting in increased Type I IFN, IL-17, IL-18, or IL-36 signaling or production have led to the successful use of targeted therapies in some of these conditions. Clinical findings such as fever patterns, type of skin lesions, genetic mutation testing, and the prevalent cytokine abnormalities can be used to group autoinflammatory diseases.

Case Report of Nonfamilial Cherubism in a Toddler: Description of Clinic-Radiographic Features and Osseous-Dental Treatments

Cherubism is a rare familial disease that occurs between the ages two and five years and regresses after puberty. Most of the cherubism cases show familial history, but there are some cases without familial histories of disorder. A two-year-old boy with a painless symmetrical progressive swelling of the jaws had visited maxillofacial radiology department. Panoramic radiograph revealed well-defined multilocular, radiolucent areas of both jaws. Computed tomography of the jaws showed well-defined, bilateral, multilocular, expansile lesions with thinning of cortical plate of maxilla and mandible and displacing the unerupted first molar anteriorly. Clinical, radiologic, and histopathologic characteristics confirmed the diagnosis of cherubism.

Cherubism With Bilateral Mandible and Maxilla Involvement: A Case Report

Cherubism is a rare, nonneoplastic, self-limiting fibro-osseous that occurs in children. Affected children usually appear normal at birth. Lesions are characterized by the replacement of bone with fibrovascular tissue containing many multinucleated giant cells. Most studies have reported cherubism to be familial and with bilateral involvement of the mandibles. The authors describe a nonfamilial case of cherubism, involving both the mandible and the maxilla, in a 4-year-old female child with slowly enlarging, painless, symmetrical swelling of both cheeks.Cherubism is a rare disease that is usually limited to the mandible, but the maxilla may be involved. Computed tomography scan and biopsy are helpful for early diagnosis.

Practice parameter for the diagnosis and management of primary immunodeficiency

The American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma & Immunology (ACAAI) have jointly accepted responsibility for establishing the "Practice parameter for the diagnosis and management of primary immunodeficiency." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion.

Onlay bone augmentation and bilateral open sinus lifting with simultaneous implant placement in a cherubic patient

A 20-year-old edentulous woman, who was previously treated with the shave of the inferior border of the mandible and malar prominent region for aesthetic facial contouring, was selected for full mouth rehabilitation of the maxillomandibular region. The patient was treated with bilateral open sinus lifting through a lateral approach in the posterior of the maxilla and an onlay bone graft with lateral ramus as a donor site in the mandible anterior. Eight implants in the maxilla and 7 in the mandible were inserted, and implant-supported prostheses were fabricated. The 18-month follow-up showed good bone condition that suggests graft interventions and implant treatment as a good treatment modality for patients with cherubism.

The calcineurin inhibitor tacrolimus as a new therapy in severe cherubism

Cherubism is a rare genetic disorder characterized by extensive growth of a bilateral granuloma of the jaws, resulting in facial disfigurement. Cherubism is caused by gain-of-function mutations in the SH3BP2 gene, leading to overactivation of nuclear factor of activated T cells, cytoplasmic 1 (NFATc1)-dependent osteoclastogenesis. Recent findings in human and mouse cherubism have suggested that calcineurin inhibitors might be drug candidates in cherubism medical treatment. A 4-year-old boy with aggressive cherubism was treated with the calcineurin inhibitor tacrolimus for 1 year, and clinical, radiological, and molecular data were obtained. Immunohistologic analysis was performed to compare preoperative and postoperative NFATc1 staining and tartrate resistant acid phosphatase (TRAP) activity. Real-time PCR was performed to analyze the relative expression levels of OPG and RANKL. After tacrolimus therapy, the patient showed significant clinical improvement, including stabilization of jaw size and intraosseous osteogenesis. Immunohistologic analyses on granuloma showed that tacrolimus caused a significant reduction in the number of TRAP-positive osteoclasts and NFATc1 nuclear staining in multinucleated giant cells. Molecular analysis showed that tacrolimus treatment also resulted in increased OPG expression. We present the first case of effective medical therapy in cherubism. Tacrolimus enhanced bone formation by stimulating osteogenesis and inhibiting osteoclastogenesis.

Loss of SH3 domain-binding protein 2 function suppresses bone destruction in tumor necrosis factor-driven and collagen-induced arthritis in mice

OBJECTIVE

SH3 domain-binding protein 2 (SH3BP2) is a signaling adapter protein that regulates the immune and skeletal systems. The present study was undertaken to investigate the role of SH3BP2 in arthritis using 2 experimental mouse models, i.e., human tumor necrosis factor α-transgenic (hTNF-Tg) mice and mice with collagen-induced arthritis (CIA).

METHODS

First, Sh3bp2(-/-) and wild-type (Sh3bp2(+/+) ) mice were crossed with hTNF-Tg mice. Inflammation and bone loss were examined by clinical inspection and histologic and micro-computed tomography analysis, and osteoclastogenesis was evaluated using primary bone marrow-derived macrophage colony-stimulating factor-dependent macrophages (BMMs). Second, CIA was induced in Sh3bp2(-/-) and Sh3bp2(+/+) mice, and the incidence and severity of arthritis were evaluated. Anti-mouse type II collagen (CII) antibody levels were measured by enzyme-linked immunosorbent assay, and lymph node cell responses to CII were determined.

RESULTS

SH3BP2 deficiency did not alter the severity of joint swelling but did suppress bone erosion in the hTNF-Tg mouse model. Bone loss at the talus and tibia was prevented in Sh3bp2(-/-) /hTNF-Tg mice compared to Sh3bp2(+/+) /hTNF-Tg mice. RANKL- and TNFα-induced osteoclastogenesis was suppressed in Sh3bp2(-/-) mouse BMM cultures. NF-ATc1 nuclear localization in response to TNFα was decreased in Sh3bp2(-/-) mouse BMMs compared to Sh3bp2(+/+) mouse BMMs. In the CIA model, SH3BP2 deficiency suppressed the incidence of arthritis and this was associated with decreased anti-CII antibody production, while antigen-specific T cell responses in lymph nodes were not significantly different between Sh3bp2(+/+) and Sh3bp2(-/-) mice.

CONCLUSION

SH3BP2 deficiency prevents loss of bone via impaired osteoclastogenesis in the hTNF-Tg mouse model and suppresses the induction of arthritis via decreased autoantibody production in the CIA model. Therefore, SH3BP2 could potentially be a therapeutic target in rheumatoid arthritis.

Cherubism in sub-saharan Africa: a first case-report in a child

Cherubism is rare disease and has been rarely reported in African pediatric population. We report here the case of a 10-year-old child who was referred to our hospital for bilateral jaws swelling. Physical examination revealed bilateral swelling symmetry of the face. Histopathological examination of the biopsy specimen showed loose fibrous stroma, proliferating fibrous connective with tissue interspersed with multinucleated giant cells, small thin walled blood vessels and scattered sparse mononuclear inflammatory infiltrate. Our patient presented cherubism. Cherubism is rarely described in children living in sub-Saharan Africa. Genetic and molecular investigations plays an important role in diagnosis but were not available in poor resources settings in developing countries such as the Democratic Republic of Congo.

Bone marrow transplantation improves autoinflammation and inflammatory bone loss in SH3BP2 knock-in cherubism mice

Cherubism (OMIM#118400) is a genetic disorder in children characterized by excessive jawbone destruction with proliferation of fibro-osseous lesions containing a large number of osteoclasts. Mutations in the SH3-domain binding protein 2 (SH3BP2) are responsible for cherubism. Analysis of the knock-in (KI) mouse model of cherubism showed that homozygous cherubism mice (Sh3bp2(KI/KI)) spontaneously develop systemic autoinflammation and inflammatory bone loss and that cherubism is a TNF-α-dependent hematopoietic disorder. In this study, we investigated whether bone marrow transplantation (BMT) is effective for the treatment of inflammation and bone loss in Sh3bp2(KI/KI) mice. Bone marrow (BM) cells from wild-type (Sh3bp2(+/+)) mice were transplanted to 6-week-old Sh3bp2(KI/KI) mice with developing inflammation and to 10-week-old Sh3bp2(KI/KI) mice with established inflammation. Six-week-old Sh3bp2(KI/KI) mice transplanted with Sh3bp2(+/+) BM cells exhibited improved body weight loss, facial swelling, and survival rate. Inflammatory lesions in the liver and lung as well as bone loss in calvaria and mandibula were ameliorated at 10weeks after BMT compared to Sh3bp2(KI/KI) mice transplanted with Sh3bp2(KI/KI) BM cells. Elevation of serum TNF-α levels was not detected after BMT. BMT was effective for up to 20weeks in 6-week-old Sh3bp2(KI/KI) mice transplanted with Sh3bp2(+/+) BM cells. BMT also ameliorated the inflammation and bone loss in 10-week-old Sh3bp2(KI/KI) mice. Thus our study demonstrates that BMT improves the inflammation and bone loss in cherubism mice. BMT may be effective for the treatment of cherubism patients.

Living with orofacial conditions: psychological distress and quality of life in adults affected with Treacher Collins syndrome, cherubism, or oligodontia/ectodermal dysplasia-a comparative study

PURPOSE

The relationship between quality of life, psychological distress, and orofacial syndromes in children and adolescents has been reported in several studies. However, little is known about differences in psychological distress and quality of life among adults with different orofacial conditions. Therefore, the aims of this study were to examine and compare these factors among three groups of adults affected by Treacher Collins syndrome (TCS), cherubism, and oligodontia/ectodermal dysplasia (ED).

METHODS

We included 11 individuals with TCS (mean age 46.9, SD 12.9 years), 15 with cherubism (mean age 50.3, SD 16.8 years), and 49 with oligodontia/ED (mean age 30.7, SD 15.6 years). The respondents completed questionnaires related to psychological distress and quality of life.

RESULTS

The oligodontia/ED group had a significantly higher level of anxiety and worse mental health-related quality of life than both the TCS and cherubism groups. Adults with TCS reported the highest level of depression, and the lowest levels of overall quality of life, well-being, and physical health-related quality of life. The cherubism group displayed the best overall quality of life, well-being, and mental health.

CONCLUSIONS

Psychological distress and quality of life differed in various orofacial conditions. This study provided insight into these aspects that may contribute to improved care.

Cherubism with multiple dental abnormalities: a rare presentation

Cherubism is a progressive, hereditary fibro-osseous lesion exclusively affecting the jaw bones. It is caused by the abnormal functioning of osteoblasts and osteoclasts, leading to replacement of normal bone by cellular fibrous tissue and immature bone, which produces painless progressive growth of the jaw, with a round facial appearance. It was first described in 1933 by Jones as 'familial multilocular cystic disease of the jaws'. The term 'cherubism' was later coined to describe the rounded facial appearance resulting from jaw hypertrophy that was reminiscent of cherubs depicted throughout Renaissance art. The bony lesions generally occur at an early age, affect one or both jaws symmetrically, and grow progressively until puberty. Spontaneous regression is seen in most cases, although surgical re-contouring may be required for others for aesthetic reasons.

SH3BP2 gain-of-function mutation exacerbates inflammation and bone loss in a murine collagen-induced arthritis model

Objective

SH3BP2 is a signaling adapter protein which regulates immune and skeletal systems. Gain-of-function mutations in SH3BP2 cause cherubism, characterized by jawbone destruction. This study was aimed to examine the role of SH3BP2 in inflammatory bone loss using a collagen-induced arthritis (CIA) model.

Methods

CIA was induced in wild-type (Sh3bp2^+/+) and heterozygous P416R SH3BP2 cherubism mutant knock-in (Sh3bp2^KI/+) mice, an SH3BP2 gain-of-function model. Severity of the arthritis was determined by assessing the paw swelling and histological analyses of the joints. Micro-CT analysis was used to determine the levels of bone loss. Inflammation and osteoclastogenesis in the joints were evaluated by quantitating the gene expression of inflammatory cytokines and osteoclast markers. Furthermore, involvement of the T- and B-cell responses was determined by draining lymph node cell culture and measurement of the serum anti-mouse type II collagen antibody levels, respectively. Finally, roles of the SH3BP2 mutation in macrophage activation and osteoclastogenesis were determined by evaluating the TNF-α production levels and osteoclast formation in bone marrow-derived M-CSF-dependent macrophage (BMM) cultures.

Results

Sh3bp2^KI/+ mice exhibited more severe inflammation and bone loss, accompanying an increased number of osteoclasts. The mRNA levels for TNF-α and osteoclast marker genes were higher in the joints of Sh3bp2^KI/+ mice. Lymph node cell culture showed that lymphocyte proliferation and IFN-γ and IL-17 production were comparable between Sh3bp2^+/+ and Sh3bp2^KI/+ cells. Serum anti-type II collagen antibody levels were comparable between Sh3bp2^+/+ and Sh3bp2^KI/+ mice. In vitro experiments showed that TNF-α production in Sh3bp2^KI/+ BMMs is elevated compared with Sh3bp2^+/+ BMMs and that RANKL-induced osteoclastogenesis is enhanced in Sh3bp2^KI/+ BMMs associated with increased NFATc1 nuclear localization.

Conclusion

Gain-of-function of SH3BP2 augments inflammation and bone loss in the CIA model through increased macrophage activation and osteoclast formation. Therefore, modulation of the SH3BP2 expression may have therapeutic potential for the treatment of rheumatoid arthritis.

Cherubism: A rare case report

Cherubism is a rare congenital disease resulting in malformation of the jaw. It occurs before the age of 5 years and regress spontaneously after puberty. It can result into enlargement of the jaw bone, tooth displacement, facial disfigurement and psychological trauma to patient. Hence, the understanding about the condition, its progression and management is necessary.

A c.1244G>A (p.Arg415Gln) mutation in SH3BP2 gene causes cherubism in a Turkish family: report of a family with review of the literature

Objectives: The present study was aimed at advancing the understanding of the pathogenesis of cherubism by presenting a case study based on history, physical examination, typical radiological features, molecular and histopathological laboratory tests and a review of the literature. Study Design: This study began with a 7-year-old boy who was referred due to mandibular overgrowth. A panoramic radiograph revealed multilocular radiolucent lesions of the upper/lower jaws suggestive of cherubism. Overall, a total of four family members were tested for SH3BP2 mutations, namely two siblings and their parents. Both siblings had been clinically diagnosed with cherubism; however, the parents were clinically normal. Peripheral blood was collected from all participants and genomic DNA sequencing was carried out. Results: A missense mutation was found in the two affected siblings and their asymptomatic mother. The mutation was a 1244 G>A transversion which resulted in an amino acid substitution from arginine to glutamine (p.Arg415Gln) in exon 9. Conclusions: The present study emphasized the importance of further clinical and molecular investigation even when only a single case of cherubism is identified within a family. Genotype-phenotype association studies in individuals with cherubism are necessary to provide important insights into the molecular mechanisms associated with this disease.

Key words:Cherubism, mandible, maxilla, SH3BP2, gene analysis, CBCT.

Non-familial cherubism: clinical and radiological findings

Cherubism is a rare, self-limiting, usually hereditary, benign fibro-osseous disease mostly affecting the jaws of the paediatric population. The disease is characterised by bilateral, diffuse and multilocular bony enlargement of the mandible and maxilla, and a tendency towards spontaneous remission. It has a typical radiographic and histopathological appearance. We present a case of a 9-year-old child lacking family history of this genetic disorder.

Genetic study of an Indian family with cherubism

Cherubism (OMIM : 118400) is an autosomal dominant disorder affecting mainly facial bones leading to disfigurement of face needing medical and surgical attention besides impairing the self esteem of person. At present, there is no medical cure and there is limited indication for surgery in such cases. So, correct diagnosis is of paramount importance to both treating physician and family. Here, the authors report a family with two affected members (mother and daughter) who were tested positive for a known pathogenic mutation and thus offered timely treatment and adequate genetic counseling.

Etanercept administration to neonatal SH3BP2 knock-in cherubism mice prevents TNF-α-induced inflammation and bone loss

Cherubism is a genetic disorder of the craniofacial skeleton caused by gain-of-function mutations in the signaling adaptor protein, SH3-domain binding protein 2 (SH3BP2). In a knock-in mouse model for cherubism, we previously demonstrated that homozygous mutant mice develop T/B cell-independent systemic macrophage inflammation leading to bone erosion and joint destruction. Homozygous mice develop multiostotic bone lesions whereas cherubism lesions in humans are limited to jawbones. We identified a critical role of tumor necrosis factor α (TNF-α) in the development of autoinflammation by creating homozygous TNF-α-deficient cherubism mutants, in which systemic inflammation and bone destruction were rescued. In this study, we examined whether postnatal administration of an anti-TNF-α antagonist can prevent or ameliorate the disease progression in cherubism mice. Neonatal homozygous mutants, in which active inflammation has not yet developed, were treated with a high dose of etanercept (25 mg/kg, twice/week) for 7 weeks. Etanercept-treated neonatal mice showed strong rescue of facial swelling and bone loss in jaws and calvariae. Destruction of joints was fully rescued in the high-dose group. Moreover, the high-dose treatment group showed a significant decrease in lung and liver inflammatory lesions. However, inflammation and bone loss, which were successfully treated by etanercept administration, recurred after etanercept discontinuation. No significant effect was observed in low-dose-treated (0.5 mg/kg, twice/week) and vehicle-treated groups. In contrast, when 10-week-old cherubism mice with fully active inflammation were treated with etanercept for 7 weeks, even the high-dose administration did not decrease bone loss or lung or liver inflammation. Taken together, the results suggest that anti-TNF-α therapy may be effective in young cherubism patients, if treated before the inflammatory phase or bone resorption occurs. Therefore, early genetic diagnosis and early treatment with anti-TNF-α antagonists may be able to prevent or ameliorate cherubism, especially in patients with a mutation in SH3BP2.

Novel nucleotide mutation leading to a recurrent amino acid alteration in SH3BP2 in a patient with cherubism

Cherubism is a rare genetic disorder characterized by progressive facial deformity caused by non-neoplastic bone lesions in the mandible and/or the maxilla. Src homology-3 binding protein 2 gene (SH3BP2) has been found to be the responsible gene, with alterations in six amino acids noted in patients with this condition. Recently, mutations in this domain have been found to cause stabilization of SH3BP2 by uncoupling with tankyrase. In this study, we identified a new 2-bp mutation that led to a recurrent amino acid change in a sporadic case of cherubism. Our findings indicate that it is important to understand the pattern of progress in typical cherubism.

Variable expressivity familial cherubism: woman transmitting cherubism without suffering the disease

Cherubism is classified within the group of benign osteo-fibrous lesions. Aside from facial deformities, it may account for major complications. It has been observed that the disease is caused by a mutation in the gene SH3BP2 (SH3-domain binding protein 2), which is located at chromosome 4pl6.3. Here we present two cases of familial cherubism, uncle and nephew, with variable clinical involvement ("Expressivity"), and one case of a woman (sister and mother, respectively), who transmitted cherubism without suffering the disease. In this article we have shown that, in familial cherubism cases, the mutation is inherited through an autosomal dominant transmission. Mutations affecting gene SH3BP2 cause variable clinical involvement (variable expressivity), involvement can be moderate, severe or may result merely in asymptomatic carriers. Since the possibility of transmission reaches 50% of chances, we believe that it is important to develop genetic counseling for both patients and carriers, in order to prevent or minimize new affected offspring.

KEYWORDS

Cherubism; SH3BP2; Expressivity.

Cherubism: panoramic and CT features in adults

OBJECTIVES

To describe the panoramic radiographic and CT features of cherubism in an unselected series of 15 adults.

METHODS

In this cross-sectional study, 15 individuals aged 29-84 years with familial non-syndromal molecularly confirmed cherubism were examined with panoramic radiography and CT. Bone abnormalities were analysed and described.

RESULTS

11 (73%) of the 15 adults had mandibular abnormalities. These abnormalities ranged from subtly detectable to severe, and were less prevalent and expansive but could be rather similar to the characteristic image features in children. Unilocular radiolucencies were more common than multilocular radiolucencies, and a specific feature of these abnormalities was that they were exclusively found in the anterior mandible.

CONCLUSIONS

The radiographic and CT abnormalities of cherubism in adults were frequent and extremely heterogeneous, with some distinct features.

Cherubism

Cherubism is one of the very few genetically determined disorders that affect only jaw bones. A typical form of cherubism in an 11 years old girl with features of bilateral swelling of the cheeks and soap bubble radiographic appearance on the maxilla and the mandible was presented. Multiple members of the first and second degree relatives were also affected. The clinical presentation of the case, differential diagnosis and treatment modalities were discussed.

Osteoimmunology: a brief introduction

Recent investigations have demonstrated extensive reciprocal interactions between the immune and skeletal systems, resulting in the establishment of osteoimmunology as a cross-disciplinary field. Here we highlight core concepts and recent advances in this emerging area of study.