Osteoglophonic Dysplasia

Mendelian MONDO:0008150 Pathograph 28 Show in embeddings browser FGFR1-related disorder Skeletal dysplasia

Osteoglophonic dysplasia is a rare skeletal disorder caused by gain-of-function mutations in FGFR1. It is characterized by craniosynostosis, rhizomelic dwarfism, nonossifying fibrous metaphyseal lesions, and severe midface hypoplasia with frontal bossing. The name derives from the Greek for "hollowed-out bone" referring to the characteristic lucent metaphyseal defects visible on radiographs. Like Pfeiffer syndrome, it results from constitutive FGFR1 activation, but produces a distinct phenotype affecting both craniofacial and appendicular skeleton with characteristic fibrous bone lesions.

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1
Inheritance
5
Pathophys.
25
Phenotypes
28
Pathograph
1
Genes
3
Medical Actions
1
References
1
Deep Research
🏷

Classifications

ISDS Skeletal Nosology
disorganized development of skeletal components
👪

Inheritance

1
Autosomal dominant HP:0000006
Osteoglophonic dysplasia follows autosomal dominant inheritance with gain-of-function mutations in FGFR1.
Autosomal dominant inheritance
Show evidence (1 reference)
PMID:29019756 SUPPORT Human Clinical
"Most of these mutations are inherited in an autosomal dominant fashion and are gain-of-function-type mutations."
Confirms autosomal dominant GOF inheritance pattern for FGFR-related skeletal disorders.
⚙

Pathophysiology

5
FGFR1 Constitutive Activation
Gain-of-function mutations in FGFR1 cause constitutive receptor activation, leading to overactive FGF signaling in skeletal tissues. This molecular defect drives multiple downstream consequences in both craniofacial and appendicular skeletal development.
Osteoblast CL:0000062 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves Osteoblast (CL:0000062). CL:0000062 is a cell type from the Cell Ontology.
FGFR1 hgnc:3688 HUGO Gene Nomenclature Committee (hgnc) Relation: this pathophysiological event involves this gene This pathophysiological event involves increased FGFR1 (hgnc:3688). hgnc:3688 is a gene from the HUGO Gene Nomenclature Committee. ↑ INCREASED
FGFR signaling pathway GO:0008543 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased FGFR signaling pathway, annotated with fibroblast growth factor receptor signaling pathway (GO:0008543). GO:0008543 is a biological process from the Gene Ontology. ↑ INCREASED
Downstream
Premature Cranial Suture Fusion
Impaired Endochondral Ossification
Aberrant Fibrous Tissue Formation
FGF23 Excess and Renal Phosphate Wasting Constitutive FGFR1 activation in bone is accompanied in some individuals by excess circulating FGF23, the phosphaturic hormone whose principal source is the osteocyte/osteoblast lineage. This is the one OGD arm that is endocrine rather than structural, and it is the feature that most sharply separates OGD from the allelic FGFR1 craniosynostosis phenotype of Pfeiffer syndrome.
Show evidence (1 reference)
PMID:29019756 SUPPORT Human Clinical
"Skeletal disorders caused by type 1 mutations include Pfeiffer syndrome (PS) and osteoglophonic dysplasia"
Confirms osteoglophonic dysplasia is caused by FGFR1 (type 1) mutations.
Premature Cranial Suture Fusion
Constitutive FGFR1 activation drives premature osteoblast differentiation at cranial suture margins, causing premature suture fusion (craniosynostosis) and resulting in abnormal skull shape with frontal bossing and midface hypoplasia.
Cranial suture morphogenesis GO:0060363 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves Cranial suture morphogenesis (GO:0060363). GO:0060363 is a biological process from the Gene Ontology.
Downstream
Multisuture craniosynostosis
Frontal bossing
Prominent supraorbital ridges
Depressed nasal bridge
Proptosis
Hypertelorism
Midface retrusion
Short nose
Anteverted nares
Low-set ears
High palate
Prognathism
Show evidence (1 reference)
PMID:38648328 SUPPORT Human Clinical
"Osteoglophonic dysplasia (OGD) is characterized by multisuture craniosynostosis (including cloverleaf skull)"
GeneReviews directly identifies multisuture craniosynostosis as a defining manifestation of OGD.
Impaired Endochondral Ossification
FGFR1 overactivation impairs normal endochondral ossification in the growth plates of long bones, leading to rhizomelic (proximal) limb shortening and short stature.
Endochondral ossification GO:0001958 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased Endochondral ossification (GO:0001958). GO:0001958 is a biological process from the Gene Ontology. ↓ DECREASED Bone development GO:0060348 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased Bone development (GO:0060348). GO:0060348 is a biological process from the Gene Ontology. ↓ DECREASED
Downstream
Disproportionate short-limb short stature
Rhizomelia
Platyspondyly
Epiphyseal dysplasia
Osteopenia
Pathologic fracture
Overlapping toe
Show evidence (1 reference)
PMID:29019756 SUPPORT Human Clinical
"FGFR1, FGFR2, and FGFR3 are crucial for both chondrogenesis and osteogenesis. Mutations in the genes encoding FGFRs, types 1-3, are responsible for various skeletal dysplasias and craniosynostosis syndromes."
Establishes that FGFR1 mutations disrupt both chondrogenesis and osteogenesis, underlying the endochondral ossification defect.
FGF23 Excess and Renal Phosphate Wasting
A subset of individuals with FGFR1-related OGD have elevated circulating FGF23 with consequent renal phosphate wasting and hypophosphatemia. FGF23 is produced chiefly by cells of the osteoblast/osteocyte lineage — the same lineage in which the activating FGFR1 allele is expressed — and acts on the proximal renal tubule to suppress phosphate reabsorption. This arm is biochemical rather than structural and is not part of the shared FGFR growth-plate/suture mechanism, so it is deliberately kept as a separate node with no `conforms_to` anchor: it is what makes OGD more than "Pfeiffer syndrome plus metaphyseal lesions".
Osteocyte CL:0000137 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves Osteocyte (CL:0000137). CL:0000137 is a cell type from the Cell Ontology.
phosphate ion homeostasis GO:0055062 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased phosphate ion homeostasis (GO:0055062). GO:0055062 is a biological process from the Gene Ontology. ↓ DECREASED
Downstream
Hypophosphatemia
Show evidence (1 reference)
PMID:40260920 SUPPORT Human Clinical
"Patients may have hypophosphatemia due to high FGF23 levels."
Establishes the FGF23-mediated route from the FGFR1 lesion to hypophosphatemia, the mechanistic step that the disease-level Hypophosphatemia phenotype otherwise had no node to hang from.
Aberrant Fibrous Tissue Formation
OGD is characterized by nonossifying fibrous lesions within metaphyseal bone, producing the characteristic radiolucent defects that give the disorder its name ("hollowed-out bone").
Downstream
Nonossifying fibromas of the long bones
Show evidence (1 reference)
PMID:15625620 SUPPORT Human Clinical
"Indeed, patients with OD present with craniosynostosis, prominent supraorbital ridge, and depressed nasal bridge, as well as the rhizomelic dwarfism and nonossifying bone lesions that are characteristic of the disorder."
White et al. explicitly identify nonossifying bone lesions as a characteristic feature of OGD.
⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Osteoglophonic Dysplasia Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
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Phenotypes

25
Ear 1
Low-set ears HP:0000369 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Low-set ears (HP:0000369). HP:0000369 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:38648328 SUPPORT Human Clinical
"distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
GeneReviews includes low-set ears in the characteristic craniofacial phenotype.
Eye 2
Proptosis HP:0000520 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Proptosis (HP:0000520). HP:0000520 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:38648328 SUPPORT Human Clinical
"distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
GeneReviews includes proptosis among the distinctive craniofacial features of OGD.
Hypertelorism HP:0000316 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hypertelorism (HP:0000316). HP:0000316 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:38648328 SUPPORT Human Clinical
"distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
The GeneReviews summary uses "widely spaced eyes," best represented by the HPO term hypertelorism.
Head and Neck 9
Multisuture craniosynostosis HP:0001363 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Multisuture craniosynostosis, annotated with Craniosynostosis (HP:0001363). HP:0001363 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:38648328 SUPPORT Human Clinical
"CLINICAL CHARACTERISTICS: Osteoglophonic dysplasia (OGD) is characterized by multisuture craniosynostosis (including cloverleaf skull)"
GeneReviews identifies multisuture craniosynostosis as a defining clinical feature of OGD.
Frontal bossing HP:0002007 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Frontal bossing (HP:0002007). HP:0002007 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:35148738 SUPPORT Human Clinical
"The details of the 4-year follow-up showed that the signs of OD were more pronounced, including dwarfism, frontal bossing, delayed skeletal maturation, anteverted nares, micrognathia, and prominent ears, but the patient's impacted teeth and edentulous jaws remained unchanged."
The 4-year follow-up case directly documents frontal bossing.
Depressed nasal bridge HP:0005280 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Depressed nasal bridge (HP:0005280). HP:0005280 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:15625620 SUPPORT Human Clinical
"Indeed, patients with OD present with craniosynostosis, prominent supraorbital ridge, and depressed nasal bridge, as well as the rhizomelic dwarfism and nonossifying bone lesions that are characteristic of the disorder."
White et al. describe depressed nasal bridge as part of the characteristic OGD facial phenotype.
Midface retrusion HP:0011800 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Midface retrusion (HP:0011800). HP:0011800 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:38648328 SUPPORT Human Clinical
"distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
GeneReviews includes midface retrusion in the characteristic craniofacial pattern.
Short nose HP:0003196 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Short nose (HP:0003196). HP:0003196 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:38648328 SUPPORT Human Clinical
"distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
Short nose is included in the GeneReviews craniofacial feature summary.
Anteverted nares HP:0000463 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Anteverted nares (HP:0000463). HP:0000463 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:35148738 SUPPORT Human Clinical
"The details of the 4-year follow-up showed that the signs of OD were more pronounced, including dwarfism, frontal bossing, delayed skeletal maturation, anteverted nares, micrognathia, and prominent ears, but the patient's impacted teeth and edentulous jaws remained unchanged."
The 4-year follow-up case directly documents anteverted nares.
High palate HP:0000218 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is High palate (HP:0000218). HP:0000218 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:38648328 SUPPORT Human Clinical
"distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
GeneReviews includes high palate in the craniofacial phenotype summary.
Delayed eruption of teeth HP:0000684 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Delayed eruption of teeth (HP:0000684). HP:0000684 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29147600 SUPPORT Human Clinical
"She presented with disproportionate short stature, craniosynostosis, a prominent supraorbital ridge, delayed teeth eruption, hypodontia, and multiple nonossifying bone lesions in the femur, tibia, and fibula."
The Indian mutation-confirmed case directly documents delayed eruption of teeth.
Hypodontia HP:0000668 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hypodontia (HP:0000668). HP:0000668 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29147600 SUPPORT Human Clinical
"Rhizomelic dwarfism, craniosynostosis, impacted teeth, hypodontia or anodontia, and multiple nonossifying bone lesions are the salient features of this condition."
Kuthiroly et al. list hypodontia, sometimes progressing to clinical anodontia, among the salient features of OGD.
Limbs 1
Nonossifying fibromas of the long bones Abnormal metaphysis morphology HP:0000944 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Nonossifying fibromas of the long bones, annotated with Abnormal metaphysis morphology (HP:0000944). HP:0000944 is a phenotype from the Human Phenotype Ontology.
Show evidence (2 references)
PMID:15625620 SUPPORT Human Clinical
"Indeed, patients with OD present with craniosynostosis, prominent supraorbital ridge, and depressed nasal bridge, as well as the rhizomelic dwarfism and nonossifying bone lesions that are characteristic of the disorder."
White et al. identify nonossifying bone lesions as characteristic of OGD.
PMID:29147600 SUPPORT Human Clinical
"She presented with disproportionate short stature, craniosynostosis, a prominent supraorbital ridge, delayed teeth eruption, hypodontia, and multiple nonossifying bone lesions in the femur, tibia, and fibula."
The Indian case localizes the lesions to the long bones; HPO lacks a more specific nonossifying fibroma term, so abnormal metaphysis morphology is the closest grounded fit.
Metabolism 1
Hypophosphatemia HP:0002148 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hypophosphatemia (HP:0002148). HP:0002148 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:40260920 SUPPORT Human Clinical
"Patients may have hypophosphatemia due to high FGF23 levels."
The 2025 OGD update explicitly identifies hypophosphatemia as part of the disease spectrum and links it to elevated FGF23.
Musculoskeletal 4
Platyspondyly HP:0000926 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Platyspondyly (HP:0000926). HP:0000926 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:8995175 SUPPORT Human Clinical
"The appearance and gradual enlargement of fibrous cortical defects and multiple nonossifying fibromata are documented in this report of a 2-year-old boy with a very rare skeletal dysplasia known as osteoglophonic dysplasia, characterized by multiple and recurrent craniosynostoses, platyspondyly,..."
Azouz and Kozlowski document platyspondyly as part of the characteristic radiographic phenotype.
Epiphyseal dysplasia HP:0002656 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Epiphyseal dysplasia (HP:0002656). HP:0002656 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:8995175 SUPPORT Human Clinical
"The appearance and gradual enlargement of fibrous cortical defects and multiple nonossifying fibromata are documented in this report of a 2-year-old boy with a very rare skeletal dysplasia known as osteoglophonic dysplasia, characterized by multiple and recurrent craniosynostoses, platyspondyly,..."
The same radiology report identifies epiphyseal dysplasia as part of the OGD skeletal pattern.
Osteopenia HP:0000938 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Osteopenia (HP:0000938). HP:0000938 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:38648328 SUPPORT Human Clinical
"Radiographs show copper beaten appearance to skull, multiple cystic long bone lesions consistent with non-ossifying fibromas, irregular vertebral bodies, and osteopenia with increased risk of fractures."
GeneReviews includes osteopenia in the characteristic radiographic findings of OGD.
Pathologic fracture HP:0002756 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Pathologic fracture (HP:0002756). HP:0002756 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:8958322 SUPPORT Human Clinical
"Manifestations, not previously reported in osteoglophonic dysplasia, present in the propositus are spontaneous fractures resulting in pseudoarthroses through cystic and dysplastic foci in his proximal femoral shafts and right humerus"
Spontaneous fractures through dysplastic bone are documented as an important, though apparently uncommon, complication.
Growth 2
Disproportionate short-limb short stature HP:0008873 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Disproportionate short-limb short stature (HP:0008873). HP:0008873 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:29147600 SUPPORT Human Clinical
"She presented with disproportionate short stature, craniosynostosis, a prominent supraorbital ridge, delayed teeth eruption, hypodontia, and multiple nonossifying bone lesions in the femur, tibia, and fibula."
The mutation-confirmed Indian case directly documents disproportionate short stature.
Rhizomelia HP:0008905 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Rhizomelia (HP:0008905). HP:0008905 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:15625620 SUPPORT Human Clinical
"Indeed, patients with OD present with craniosynostosis, prominent supraorbital ridge, and depressed nasal bridge, as well as the rhizomelic dwarfism and nonossifying bone lesions that are characteristic of the disorder."
White et al. describe rhizomelic dwarfism as a characteristic skeletal feature of OGD.
Other 5
Prominent supraorbital ridges HP:0000336 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Prominent supraorbital ridges (HP:0000336). HP:0000336 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:15625620 SUPPORT Human Clinical
"Indeed, patients with OD present with craniosynostosis, prominent supraorbital ridge, and depressed nasal bridge, as well as the rhizomelic dwarfism and nonossifying bone lesions that are characteristic of the disorder."
White et al. identify prominent supraorbital ridging as a characteristic craniofacial manifestation.
Impacted teeth Impacted tooth HP:0011079 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Impacted tooth (HP:0011079). HP:0011079 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:16918680 SUPPORT Human Clinical
"Radiographically, multiple lucent lesions were present in the tubular bones and mandible as well as several impacted teeth."
Roberts et al. directly document multiple impacted teeth in a long-term follow-up case.
Gingival overgrowth HP:0000212 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Gingival overgrowth (HP:0000212). HP:0000212 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:38648328 SUPPORT Human Clinical
"distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
GeneReviews includes gingival overgrowth among the characteristic craniofacial and oral features.
Overlapping toe HP:0001845 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Overlapping toe (HP:0001845). HP:0001845 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:40260920 SUPPORT Human Clinical
"Both showed classic symptoms as well as signs not previously reported, including elevated frontal temperature and overlapping toes."
The 2025 case series expands the phenotype to include overlapping toes.
Prognathism Mandibular prognathia HP:0000303 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Mandibular prognathia (HP:0000303). HP:0000303 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:38648328 SUPPORT Human Clinical
"distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
GeneReviews includes prognathism among the characteristic craniofacial features of OGD.
🧬

Genetic Associations

1
FGFR1 gain-of-function mutations (Causative)
Gene: FGFR1 hgnc:3688 HUGO Gene Nomenclature Committee (hgnc) Relation: this disease-associated gene is this gene This disease-associated gene is FGFR1 (hgnc:3688). hgnc:3688 is a gene from the HUGO Gene Nomenclature Committee.
Show evidence (2 references)
PMID:29019756 SUPPORT Human Clinical
"Skeletal disorders caused by type 1 mutations include Pfeiffer syndrome (PS) and osteoglophonic dysplasia"
Confirms FGFR1 mutations cause osteoglophonic dysplasia.
CGGV:assertion_d958e743-2ca0-4bb9-a198-364dd58005c3-2021-03-22T203501.315Z SUPPORT Other
"FGFR1 | HGNC:3688 | osteoglophonic dwarfism | MONDO:0008150 | AD | Limited"
ClinGen classifies the FGFR1-osteoglophonic dwarfism gene-disease relationship as limited with autosomal dominant inheritance.
💊

Medical Actions

3
Orthopedic management
Action: Orthopedic managementNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Orthopedic management, annotated with Surgical Procedure (NCIT:C15329). NCIT:C15329 is a clinical intervention from the NCI Thesaurus. Ontology label: Surgical Procedure NCIT:C15329
Orthopedic management of skeletal complications including rhizomelic dwarfism and fibrous bone lesions. Surgical intervention may be required for severe limb deformities.
Craniofacial surgery
Action: Craniofacial surgeryNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Craniofacial surgery, annotated with Surgical Procedure (NCIT:C15329). NCIT:C15329 is a clinical intervention from the NCI Thesaurus. Ontology label: Surgical Procedure NCIT:C15329
Surgical correction of craniosynostosis and midface hypoplasia as needed.
Denosumab for aggressive central giant cell granuloma
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: denosumab NCIT:C61313 NCI Thesaurus (NCIT) Relation: this treatment uses this therapeutic agent This treatment uses denosumab (NCIT:C61313). NCIT:C61313 is a therapeutic agent from the NCI Thesaurus.
The metaphyseal/jaw fibro-osseous lesions of OGD can behave aggressively as recurrent central giant cell granulomas (CGCG). In a long-followed adult with molecularly characterized OGD whose maxillary CGCG recurred through repeated surgery and failed alendronate, switching to the anti-RANKL monoclonal antibody denosumab — which acts directly on the osteoclast-like giant cells of the lesion rather than indirectly on bone resorption — produced marked tumour regression. This is a single case, not a trial, and denosumab in a growing skeleton carries its own hazards (medication-related osteonecrosis of the jaw, hypocalcaemia, atypical fracture, post-treatment rebound), so it is recorded here as an emerging lesion-directed option rather than standard care.
Mechanism Target:
INHIBITS Aberrant Fibrous Tissue Formation — Denosumab targets the osteoclast-like giant cells that populate the fibro-osseous lesion, acting on the lesional tissue itself rather than on the upstream FGFR1 lesion, which remains untreated.
Show evidence (1 reference)
PMID:41093593 SUPPORT Human Clinical
"A multidisciplinary team initiated treatment with Denosumab, a monoclonal antibody that inhibits receptor activator of nuclear factor-κB ligand (RANKL) and directly targets osteoclast-like giant cells."
States the mechanism by which denosumab acts on the OGD-associated giant-cell lesion.
Show evidence (2 references)
PMID:41093593 SUPPORT Human Clinical
"The therapeutic switch resulted in marked tumor regression, effectively reducing surgical burden and improving quality of life."
Reports the clinical response to denosumab after alendronate failure in an individual with osteoglophonic dysplasia.
PMID:41093593 SUPPORT Human Clinical
"However, ongoing surveillance for adverse effects such as medication-related osteonecrosis of the jaw, hypocalcemia, and atypical fractures is essential."
Records the safety caveat that keeps this an emerging rather than established treatment.
{ }

Source YAML

click to show 
name: Osteoglophonic Dysplasia
synonyms:
- Osteoglophonic dysplasia, FGFR1-related
creation_date: '2026-04-04T12:00:00Z'
category: Mendelian
description: >-
  Osteoglophonic dysplasia is a rare skeletal disorder caused by gain-of-function mutations
  in FGFR1. It is characterized by craniosynostosis, rhizomelic dwarfism, nonossifying
  fibrous metaphyseal lesions, and severe midface hypoplasia with frontal bossing. The name
  derives from the Greek for "hollowed-out bone" referring to the characteristic lucent
  metaphyseal defects visible on radiographs. Like Pfeiffer syndrome, it results from
  constitutive FGFR1 activation, but produces a distinct phenotype affecting both
  craniofacial and appendicular skeleton with characteristic fibrous bone lesions.
disease_term:
  preferred_term: osteoglophonic dysplasia
  term:
    id: MONDO:0008150
    label: osteoglophonic dysplasia
parents:
- FGFR1-related disorder
- Skeletal dysplasia
inheritance:
- name: Autosomal dominant
  inheritance_term:
    preferred_term: Autosomal dominant inheritance
    term:
      id: HP:0000006
      label: Autosomal dominant inheritance
  description: >-
    Osteoglophonic dysplasia follows autosomal dominant inheritance with
    gain-of-function mutations in FGFR1.
  evidence:
  - reference: PMID:29019756
    reference_title: "Imaging of Skeletal Disorders Caused by Fibroblast Growth Factor Receptor Gene Mutations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Most of these mutations are inherited in an autosomal dominant fashion and are gain-of-function-type mutations."
    explanation: Confirms autosomal dominant GOF inheritance pattern for FGFR-related skeletal disorders.
classifications:
  isds_skeletal_category:
  - classification_value: disorganized_development_of_skeletal_components
    notes: >-
      ISDS Nosology and Classification of Genetic Skeletal Disorders, 2019
      revision (Mortier et al., PMID:31633310), Table 1 group 29 "Disorganized
      development of skeletal components group"; listed as "Osteoglophonic
      dysplasia".
pathophysiology:
- name: FGFR1 Constitutive Activation
  conforms_to: "fgfr_gain_of_function_skeletal_dysplasia#Constitutive FGFR Activation"
  biological_scale: MOLECULAR
  description: >-
    Gain-of-function mutations in FGFR1 cause constitutive receptor activation,
    leading to overactive FGF signaling in skeletal tissues. This molecular defect
    drives multiple downstream consequences in both craniofacial and appendicular
    skeletal development.
  gene:
    preferred_term: FGFR1
    description: Fibroblast growth factor receptor 1, constitutively activated by gain-of-function mutations in osteoglophonic dysplasia.
    modifier: INCREASED
    term:
      id: hgnc:3688
      label: FGFR1
  cell_types:
  - preferred_term: Osteoblast
    term:
      id: CL:0000062
      label: osteoblast
  biological_processes:
  - preferred_term: FGFR signaling pathway
    term:
      id: GO:0008543
      label: fibroblast growth factor receptor signaling pathway
    modifier: INCREASED
  evidence:
  - reference: PMID:29019756
    reference_title: "Imaging of Skeletal Disorders Caused by Fibroblast Growth Factor Receptor Gene Mutations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Skeletal disorders caused by type 1 mutations include Pfeiffer syndrome (PS) and osteoglophonic dysplasia"
    explanation: Confirms osteoglophonic dysplasia is caused by FGFR1 (type 1) mutations.
  downstream:
  - target: Premature Cranial Suture Fusion
  - target: Impaired Endochondral Ossification
  - target: Aberrant Fibrous Tissue Formation
  - target: FGF23 Excess and Renal Phosphate Wasting
    description: >-
      Constitutive FGFR1 activation in bone is accompanied in some individuals by
      excess circulating FGF23, the phosphaturic hormone whose principal source is
      the osteocyte/osteoblast lineage. This is the one OGD arm that is endocrine
      rather than structural, and it is the feature that most sharply separates OGD
      from the allelic FGFR1 craniosynostosis phenotype of Pfeiffer syndrome.
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
- name: Premature Cranial Suture Fusion
  conforms_to: "fgfr_gain_of_function_skeletal_dysplasia#Premature Suture Fusion and Craniosynostosis"
  biological_scale: TISSUE
  description: >-
    Constitutive FGFR1 activation drives premature osteoblast differentiation at
    cranial suture margins, causing premature suture fusion (craniosynostosis) and
    resulting in abnormal skull shape with frontal bossing and midface hypoplasia.
  biological_processes:
  - preferred_term: Cranial suture morphogenesis
    term:
      id: GO:0060363
      label: cranial suture morphogenesis
  evidence:
  - reference: PMID:38648328
    reference_title: "Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Osteoglophonic dysplasia (OGD) is characterized by multisuture craniosynostosis (including cloverleaf skull)"
    explanation: GeneReviews directly identifies multisuture craniosynostosis as a defining manifestation of OGD.
  downstream:
  - target: Multisuture craniosynostosis
  - target: Frontal bossing
  - target: Prominent supraorbital ridges
  - target: Depressed nasal bridge
  - target: Proptosis
  - target: Hypertelorism
  - target: Midface retrusion
  - target: Short nose
  - target: Anteverted nares
  - target: Low-set ears
  - target: High palate
  - target: Prognathism
- name: Impaired Endochondral Ossification
  conforms_to: "fgfr_gain_of_function_skeletal_dysplasia#Impaired Endochondral Ossification and Chondrodysplasia"
  biological_scale: TISSUE
  description: >-
    FGFR1 overactivation impairs normal endochondral ossification in the growth
    plates of long bones, leading to rhizomelic (proximal) limb shortening and
    short stature.
  biological_processes:
  - preferred_term: Endochondral ossification
    term:
      id: GO:0001958
      label: endochondral ossification
    modifier: DECREASED
  - preferred_term: Bone development
    term:
      id: GO:0060348
      label: bone development
    modifier: DECREASED
  evidence:
  - reference: PMID:29019756
    reference_title: "Imaging of Skeletal Disorders Caused by Fibroblast Growth Factor Receptor Gene Mutations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "FGFR1, FGFR2, and FGFR3 are crucial for both chondrogenesis and osteogenesis. Mutations in the genes encoding FGFRs, types 1-3, are responsible for various skeletal dysplasias and craniosynostosis syndromes."
    explanation: Establishes that FGFR1 mutations disrupt both chondrogenesis and osteogenesis, underlying the endochondral ossification defect.
  downstream:
  - target: Disproportionate short-limb short stature
  - target: Rhizomelia
  - target: Platyspondyly
  - target: Epiphyseal dysplasia
  - target: Osteopenia
  - target: Pathologic fracture
  - target: Overlapping toe
- name: FGF23 Excess and Renal Phosphate Wasting
  biological_scale: ORGANISM
  description: >-
    A subset of individuals with FGFR1-related OGD have elevated circulating
    FGF23 with consequent renal phosphate wasting and hypophosphatemia. FGF23 is
    produced chiefly by cells of the osteoblast/osteocyte lineage — the same
    lineage in which the activating FGFR1 allele is expressed — and acts on the
    proximal renal tubule to suppress phosphate reabsorption. This arm is
    biochemical rather than structural and is not part of the shared FGFR
    growth-plate/suture mechanism, so it is deliberately kept as a separate node
    with no `conforms_to` anchor: it is what makes OGD more than "Pfeiffer
    syndrome plus metaphyseal lesions".
  cell_types:
  - preferred_term: Osteocyte
    term:
      id: CL:0000137
      label: osteocyte
  biological_processes:
  - preferred_term: phosphate ion homeostasis
    term:
      id: GO:0055062
      label: phosphate ion homeostasis
    modifier: DECREASED
  evidence:
  - reference: PMID:40260920
    reference_title: "New Phenotypic Features in FGFR1-Related Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Patients may have hypophosphatemia due to high FGF23 levels."
    explanation: >-
      Establishes the FGF23-mediated route from the FGFR1 lesion to
      hypophosphatemia, the mechanistic step that the disease-level
      Hypophosphatemia phenotype otherwise had no node to hang from.
  downstream:
  - target: Hypophosphatemia
- name: Aberrant Fibrous Tissue Formation
  biological_scale: TISSUE
  description: >-
    OGD is characterized by nonossifying fibrous lesions within metaphyseal
    bone, producing the characteristic radiolucent defects that give the
    disorder its name ("hollowed-out bone").
  evidence:
  - reference: PMID:15625620
    reference_title: "Mutations that cause osteoglophonic dysplasia define novel roles for FGFR1 in bone elongation."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Indeed, patients with OD present with craniosynostosis, prominent supraorbital ridge, and depressed nasal bridge, as well as the rhizomelic dwarfism and nonossifying bone lesions that are characteristic of the disorder."
    explanation: White et al. explicitly identify nonossifying bone lesions as a characteristic feature of OGD.
  downstream:
  - target: Nonossifying fibromas of the long bones
phenotypes:
- category: Craniofacial
  name: Multisuture craniosynostosis
  description: >-
    Premature fusion of multiple cranial sutures is a defining manifestation and
    can be severe enough to produce a cloverleaf skull configuration.
  phenotype_term:
    preferred_term: Multisuture craniosynostosis
    term:
      id: HP:0001363
      label: Craniosynostosis
  evidence:
  - reference: PMID:38648328
    reference_title: "Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "CLINICAL CHARACTERISTICS: Osteoglophonic dysplasia (OGD) is characterized by multisuture craniosynostosis (including cloverleaf skull)"
    explanation: GeneReviews identifies multisuture craniosynostosis as a defining clinical feature of OGD.
- category: Musculoskeletal
  name: Disproportionate short-limb short stature
  description: >-
    Marked short stature with disproportionate limb shortening is a core skeletal
    manifestation.
  phenotype_term:
    preferred_term: Disproportionate short-limb short stature
    term:
      id: HP:0008873
      label: Disproportionate short-limb short stature
  evidence:
  - reference: PMID:29147600
    reference_title: "Osteoglophonic Dysplasia: Phenotypic and Radiological Clues."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "She presented with disproportionate short stature, craniosynostosis, a prominent supraorbital ridge, delayed teeth eruption, hypodontia, and multiple nonossifying bone lesions in the femur, tibia, and fibula."
    explanation: The mutation-confirmed Indian case directly documents disproportionate short stature.
- category: Musculoskeletal
  name: Rhizomelia
  description: >-
    Proximal limb shortening contributes substantially to the dwarfing phenotype.
  phenotype_term:
    preferred_term: Rhizomelia
    term:
      id: HP:0008905
      label: Rhizomelia
  evidence:
  - reference: PMID:15625620
    reference_title: "Mutations that cause osteoglophonic dysplasia define novel roles for FGFR1 in bone elongation."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Indeed, patients with OD present with craniosynostosis, prominent supraorbital ridge, and depressed nasal bridge, as well as the rhizomelic dwarfism and nonossifying bone lesions that are characteristic of the disorder."
    explanation: White et al. describe rhizomelic dwarfism as a characteristic skeletal feature of OGD.
- category: Musculoskeletal
  name: Nonossifying fibromas of the long bones
  description: >-
    Multiple metaphyseal or cystic lucent lesions, often involving the long bones
    and sometimes the mandible, are a radiographic hallmark of OGD.
  phenotype_term:
    preferred_term: Nonossifying fibromas of the long bones
    term:
      id: HP:0000944
      label: Abnormal metaphysis morphology
  evidence:
  - reference: PMID:15625620
    reference_title: "Mutations that cause osteoglophonic dysplasia define novel roles for FGFR1 in bone elongation."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Indeed, patients with OD present with craniosynostosis, prominent supraorbital ridge, and depressed nasal bridge, as well as the rhizomelic dwarfism and nonossifying bone lesions that are characteristic of the disorder."
    explanation: White et al. identify nonossifying bone lesions as characteristic of OGD.
  - reference: PMID:29147600
    reference_title: "Osteoglophonic Dysplasia: Phenotypic and Radiological Clues."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "She presented with disproportionate short stature, craniosynostosis, a prominent supraorbital ridge, delayed teeth eruption, hypodontia, and multiple nonossifying bone lesions in the femur, tibia, and fibula."
    explanation: The Indian case localizes the lesions to the long bones; HPO lacks a more specific nonossifying fibroma term, so abnormal metaphysis morphology is the closest grounded fit.
- category: Musculoskeletal
  name: Platyspondyly
  description: >-
    Flattened vertebral bodies are a recurrent radiographic feature.
  phenotype_term:
    preferred_term: Platyspondyly
    term:
      id: HP:0000926
      label: Platyspondyly
  evidence:
  - reference: PMID:8995175
    reference_title: "Osteoglophonic dysplasia: appearance and progression of multiple nonossifying fibromata."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The appearance and gradual enlargement of fibrous cortical defects and multiple nonossifying fibromata are documented in this report of a 2-year-old boy with a very rare skeletal dysplasia known as osteoglophonic dysplasia, characterized by multiple and recurrent craniosynostoses, platyspondyly, short tubular bones, and epiphyseal dysplasia."
    explanation: Azouz and Kozlowski document platyspondyly as part of the characteristic radiographic phenotype.
- category: Musculoskeletal
  name: Epiphyseal dysplasia
  description: >-
    Epiphyseal involvement accompanies the spondylo-metaphyseal abnormalities in
    some affected individuals.
  phenotype_term:
    preferred_term: Epiphyseal dysplasia
    term:
      id: HP:0002656
      label: Epiphyseal dysplasia
  evidence:
  - reference: PMID:8995175
    reference_title: "Osteoglophonic dysplasia: appearance and progression of multiple nonossifying fibromata."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The appearance and gradual enlargement of fibrous cortical defects and multiple nonossifying fibromata are documented in this report of a 2-year-old boy with a very rare skeletal dysplasia known as osteoglophonic dysplasia, characterized by multiple and recurrent craniosynostoses, platyspondyly, short tubular bones, and epiphyseal dysplasia."
    explanation: The same radiology report identifies epiphyseal dysplasia as part of the OGD skeletal pattern.
- category: Musculoskeletal
  name: Osteopenia
  description: >-
    Reduced bone density is part of the characteristic radiographic phenotype and
    likely contributes to bone fragility.
  phenotype_term:
    preferred_term: Osteopenia
    term:
      id: HP:0000938
      label: Osteopenia
  evidence:
  - reference: PMID:38648328
    reference_title: "Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Radiographs show copper beaten appearance to skull, multiple cystic long bone lesions consistent with non-ossifying fibromas, irregular vertebral bodies, and osteopenia with increased risk of fractures."
    explanation: GeneReviews includes osteopenia in the characteristic radiographic findings of OGD.
- category: Musculoskeletal
  name: Pathologic fracture
  description: >-
    Fragility fractures can occur through dysplastic cystic lesions and may lead
    to pseudoarthrosis in severe cases.
  phenotype_term:
    preferred_term: Pathologic fracture
    term:
      id: HP:0002756
      label: Pathologic fracture
  evidence:
  - reference: PMID:8958322
    reference_title: "Osteoglophonic dysplasia: review and further delineation of the syndrome."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Manifestations, not previously reported in osteoglophonic dysplasia, present in the propositus are spontaneous fractures resulting in pseudoarthroses through cystic and dysplastic foci in his proximal femoral shafts and right humerus"
    explanation: Spontaneous fractures through dysplastic bone are documented as an important, though apparently uncommon, complication.
- category: Craniofacial
  name: Frontal bossing
  description: >-
    Forehead prominence contributes to the characteristic craniofacial appearance.
  phenotype_term:
    preferred_term: Frontal bossing
    term:
      id: HP:0002007
      label: Frontal bossing
  evidence:
  - reference: PMID:35148738
    reference_title: "Abnormal eruption of teeth in relation to FGFR1 heterozygote mutation: a rare case of osteoglophonic dysplasia with 4-year follow-up."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The details of the 4-year follow-up showed that the signs of OD were more pronounced, including dwarfism, frontal bossing, delayed skeletal maturation, anteverted nares, micrognathia, and prominent ears, but the patient's impacted teeth and edentulous jaws remained unchanged."
    explanation: The 4-year follow-up case directly documents frontal bossing.
- category: Craniofacial
  name: Prominent supraorbital ridges
  description: >-
    Supraorbital ridging is part of the characteristic facial gestalt.
  phenotype_term:
    preferred_term: Prominent supraorbital ridges
    term:
      id: HP:0000336
      label: Prominent supraorbital ridges
  evidence:
  - reference: PMID:15625620
    reference_title: "Mutations that cause osteoglophonic dysplasia define novel roles for FGFR1 in bone elongation."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Indeed, patients with OD present with craniosynostosis, prominent supraorbital ridge, and depressed nasal bridge, as well as the rhizomelic dwarfism and nonossifying bone lesions that are characteristic of the disorder."
    explanation: White et al. identify prominent supraorbital ridging as a characteristic craniofacial manifestation.
- category: Craniofacial
  name: Depressed nasal bridge
  description: >-
    A depressed nasal bridge is a recurring facial feature.
  phenotype_term:
    preferred_term: Depressed nasal bridge
    term:
      id: HP:0005280
      label: Depressed nasal bridge
  evidence:
  - reference: PMID:15625620
    reference_title: "Mutations that cause osteoglophonic dysplasia define novel roles for FGFR1 in bone elongation."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Indeed, patients with OD present with craniosynostosis, prominent supraorbital ridge, and depressed nasal bridge, as well as the rhizomelic dwarfism and nonossifying bone lesions that are characteristic of the disorder."
    explanation: White et al. describe depressed nasal bridge as part of the characteristic OGD facial phenotype.
- category: Craniofacial
  name: Proptosis
  description: >-
    Ocular prominence is part of the distinctive craniofacial phenotype.
  phenotype_term:
    preferred_term: Proptosis
    term:
      id: HP:0000520
      label: Proptosis
  evidence:
  - reference: PMID:38648328
    reference_title: "Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
    explanation: GeneReviews includes proptosis among the distinctive craniofacial features of OGD.
- category: Craniofacial
  name: Hypertelorism
  description: >-
    Widely spaced eyes are part of the characteristic craniofacial dysmorphism.
  phenotype_term:
    preferred_term: Hypertelorism
    term:
      id: HP:0000316
      label: Hypertelorism
  evidence:
  - reference: PMID:38648328
    reference_title: "Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
    explanation: The GeneReviews summary uses "widely spaced eyes," best represented by the HPO term hypertelorism.
- category: Craniofacial
  name: Midface retrusion
  description: >-
    Midfacial hypoplasia or retrusion is a recurrent and clinically important
    facial manifestation.
  phenotype_term:
    preferred_term: Midface retrusion
    term:
      id: HP:0011800
      label: Midface retrusion
  evidence:
  - reference: PMID:38648328
    reference_title: "Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
    explanation: GeneReviews includes midface retrusion in the characteristic craniofacial pattern.
- category: Craniofacial
  name: Short nose
  description: >-
    Short nasal length is part of the recurring OGD facial gestalt.
  phenotype_term:
    preferred_term: Short nose
    term:
      id: HP:0003196
      label: Short nose
  evidence:
  - reference: PMID:38648328
    reference_title: "Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
    explanation: Short nose is included in the GeneReviews craniofacial feature summary.
- category: Craniofacial
  name: Anteverted nares
  description: >-
    Upturned nostrils are part of the typical craniofacial phenotype.
  phenotype_term:
    preferred_term: Anteverted nares
    term:
      id: HP:0000463
      label: Anteverted nares
  evidence:
  - reference: PMID:35148738
    reference_title: "Abnormal eruption of teeth in relation to FGFR1 heterozygote mutation: a rare case of osteoglophonic dysplasia with 4-year follow-up."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The details of the 4-year follow-up showed that the signs of OD were more pronounced, including dwarfism, frontal bossing, delayed skeletal maturation, anteverted nares, micrognathia, and prominent ears, but the patient's impacted teeth and edentulous jaws remained unchanged."
    explanation: The 4-year follow-up case directly documents anteverted nares.
- category: Craniofacial
  name: Low-set ears
  description: >-
    Low-set ears are part of the broader craniofacial dysmorphism.
  phenotype_term:
    preferred_term: Low-set ears
    term:
      id: HP:0000369
      label: Low-set ears
  evidence:
  - reference: PMID:38648328
    reference_title: "Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
    explanation: GeneReviews includes low-set ears in the characteristic craniofacial phenotype.
- category: Craniofacial
  name: High palate
  description: >-
    A high palate contributes to the characteristic craniofacial and dental
    phenotype.
  phenotype_term:
    preferred_term: High palate
    term:
      id: HP:0000218
      label: High palate
  evidence:
  - reference: PMID:38648328
    reference_title: "Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
    explanation: GeneReviews includes high palate in the craniofacial phenotype summary.
- category: Dental
  name: Delayed eruption of teeth
  description: >-
    Tooth eruption is often severely delayed and may progress to functional
    failure of eruption.
  phenotype_term:
    preferred_term: Delayed eruption of teeth
    term:
      id: HP:0000684
      label: Delayed eruption of teeth
  evidence:
  - reference: PMID:29147600
    reference_title: "Osteoglophonic Dysplasia: Phenotypic and Radiological Clues."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "She presented with disproportionate short stature, craniosynostosis, a prominent supraorbital ridge, delayed teeth eruption, hypodontia, and multiple nonossifying bone lesions in the femur, tibia, and fibula."
    explanation: The Indian mutation-confirmed case directly documents delayed eruption of teeth.
- category: Dental
  name: Impacted teeth
  description: >-
    Multiple permanent teeth may remain unerupted and impacted despite root
    development.
  phenotype_term:
    preferred_term: Impacted tooth
    term:
      id: HP:0011079
      label: Impacted tooth
  evidence:
  - reference: PMID:16918680
    reference_title: "Osteoglophonic dysplasia: dental and orthodontic implications."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Radiographically, multiple lucent lesions were present in the tubular bones and mandible as well as several impacted teeth."
    explanation: Roberts et al. directly document multiple impacted teeth in a long-term follow-up case.
- category: Dental
  name: Hypodontia
  description: >-
    Reduced tooth number is a recurrent dental manifestation; some reports also
    describe clinically absent dentition.
  phenotype_term:
    preferred_term: Hypodontia
    term:
      id: HP:0000668
      label: Hypodontia
  evidence:
  - reference: PMID:29147600
    reference_title: "Osteoglophonic Dysplasia: Phenotypic and Radiological Clues."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Rhizomelic dwarfism, craniosynostosis, impacted teeth, hypodontia or anodontia, and multiple nonossifying bone lesions are the salient features of this condition."
    explanation: Kuthiroly et al. list hypodontia, sometimes progressing to clinical anodontia, among the salient features of OGD.
- category: Dental
  name: Gingival overgrowth
  description: >-
    Gingival tissue overgrowth contributes to the characteristic oral phenotype.
  phenotype_term:
    preferred_term: Gingival overgrowth
    term:
      id: HP:0000212
      label: Gingival overgrowth
  evidence:
  - reference: PMID:38648328
    reference_title: "Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
    explanation: GeneReviews includes gingival overgrowth among the characteristic craniofacial and oral features.
- category: Metabolic
  name: Hypophosphatemia
  description: >-
    Some patients develop hypophosphatemia, apparently related to excess FGF23.
  phenotype_term:
    preferred_term: Hypophosphatemia
    term:
      id: HP:0002148
      label: Hypophosphatemia
  evidence:
  - reference: PMID:40260920
    reference_title: "New Phenotypic Features in FGFR1-Related Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Patients may have hypophosphatemia due to high FGF23 levels."
    explanation: The 2025 OGD update explicitly identifies hypophosphatemia as part of the disease spectrum and links it to elevated FGF23.
- category: Musculoskeletal
  name: Overlapping toe
  description: >-
    Overlapping toes were recently reported as a newly recognized appendicular
    feature in two individuals with FGFR1-related OGD.
  phenotype_term:
    preferred_term: Overlapping toe
    term:
      id: HP:0001845
      label: Overlapping toe
  evidence:
  - reference: PMID:40260920
    reference_title: "New Phenotypic Features in FGFR1-Related Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Both showed classic symptoms as well as signs not previously reported, including elevated frontal temperature and overlapping toes."
    explanation: The 2025 case series expands the phenotype to include overlapping toes.
- category: Craniofacial
  name: Prognathism
  description: >-
    Relative mandibular prominence contributes to the characteristic craniofacial
    profile.
  phenotype_term:
    preferred_term: Mandibular prognathia
    term:
      id: HP:0000303
      label: Mandibular prognathia
  evidence:
  - reference: PMID:38648328
    reference_title: "Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "distinctive craniofacial features (prominent forehead, proptosis, widely spaced eyes, low-set ears, midface retrusion, short nose, anteverted nares, prognathism, high palate, failure of tooth eruption, and gingival overgrowth)"
    explanation: GeneReviews includes prognathism among the characteristic craniofacial features of OGD.
genetic:
- name: FGFR1 gain-of-function mutations
  association: Causative
  gene_term:
    preferred_term: FGFR1
    term:
      id: hgnc:3688
      label: FGFR1
  notes: >-
    Activating mutations in FGFR1 cause osteoglophonic dysplasia. The mutations
    lead to constitutive receptor activation affecting craniofacial and long bone
    development with characteristic nonossifying fibrous metaphyseal lesions.
  evidence:
  - reference: PMID:29019756
    reference_title: "Imaging of Skeletal Disorders Caused by Fibroblast Growth Factor Receptor Gene Mutations."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Skeletal disorders caused by type 1 mutations include Pfeiffer syndrome (PS) and osteoglophonic dysplasia"
    explanation: Confirms FGFR1 mutations cause osteoglophonic dysplasia.
  - reference: CGGV:assertion_d958e743-2ca0-4bb9-a198-364dd58005c3-2021-03-22T203501.315Z
    reference_title: "FGFR1 / osteoglophonic dwarfism (Limited)"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "FGFR1 | HGNC:3688 | osteoglophonic dwarfism | MONDO:0008150 | AD | Limited"
    explanation: ClinGen classifies the FGFR1-osteoglophonic dwarfism gene-disease relationship as limited with autosomal dominant inheritance.
treatments:
- name: Orthopedic management
  description: >-
    Orthopedic management of skeletal complications including rhizomelic dwarfism
    and fibrous bone lesions. Surgical intervention may be required for severe
    limb deformities.
  therapeutic_modality: SURGERY
  treatment_term:
    preferred_term: Orthopedic management
    term:
      id: NCIT:C15329
      label: Surgical Procedure
- name: Craniofacial surgery
  description: Surgical correction of craniosynostosis and midface hypoplasia as needed.
  therapeutic_modality: SURGERY
  treatment_term:
    preferred_term: Craniofacial surgery
    term:
      id: NCIT:C15329
      label: Surgical Procedure
- name: Denosumab for aggressive central giant cell granuloma
  description: >-
    The metaphyseal/jaw fibro-osseous lesions of OGD can behave aggressively as
    recurrent central giant cell granulomas (CGCG). In a long-followed adult with
    molecularly characterized OGD whose maxillary CGCG recurred through repeated
    surgery and failed alendronate, switching to the anti-RANKL monoclonal
    antibody denosumab — which acts directly on the osteoclast-like giant cells of
    the lesion rather than indirectly on bone resorption — produced marked tumour
    regression. This is a single case, not a trial, and denosumab in a growing
    skeleton carries its own hazards (medication-related osteonecrosis of the jaw,
    hypocalcaemia, atypical fracture, post-treatment rebound), so it is recorded
    here as an emerging lesion-directed option rather than standard care.
  therapeutic_modality: MONOCLONAL_ANTIBODY
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: denosumab
      term:
        id: NCIT:C61313
        label: Denosumab
  target_mechanisms:
  - target: Aberrant Fibrous Tissue Formation
    treatment_effect: INHIBITS
    description: >-
      Denosumab targets the osteoclast-like giant cells that populate the
      fibro-osseous lesion, acting on the lesional tissue itself rather than on
      the upstream FGFR1 lesion, which remains untreated.
    evidence:
    - reference: PMID:41093593
      reference_title: "Denosumab for the Treatment of Aggressive Recurrent Central Giant Cell Granuloma of the Maxilla in a Patient with Osteoglophonic Dysplasia."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "A multidisciplinary team initiated treatment with Denosumab, a monoclonal antibody that inhibits receptor activator of nuclear factor-\u03baB ligand (RANKL) and directly targets osteoclast-like giant cells."
      explanation: >-
        States the mechanism by which denosumab acts on the OGD-associated
        giant-cell lesion.
  evidence:
  - reference: PMID:41093593
    reference_title: "Denosumab for the Treatment of Aggressive Recurrent Central Giant Cell Granuloma of the Maxilla in a Patient with Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The therapeutic switch resulted in marked tumor regression, effectively reducing surgical burden and improving quality of life."
    explanation: >-
      Reports the clinical response to denosumab after alendronate failure in an
      individual with osteoglophonic dysplasia.
  - reference: PMID:41093593
    reference_title: "Denosumab for the Treatment of Aggressive Recurrent Central Giant Cell Granuloma of the Maxilla in a Patient with Osteoglophonic Dysplasia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "However, ongoing surveillance for adverse effects such as medication-related osteonecrosis of the jaw, hypocalcemia, and atypical fractures is essential."
    explanation: >-
      Records the safety caveat that keeps this an emerging rather than
      established treatment.
references:
- reference: PMID:38648328
  title: "Osteoglophonic Dysplasia."
  tags:
  - GeneReviews
  findings: []
📚

References & Deep Research

References

1
PMID:38648328
Osteoglophonic Dysplasia.
No top-level findings curated for this source.

Deep Research

1
Osteoglophonic Dysplasia Deep Research Notes ▸

Osteoglophonic Dysplasia Deep Research Notes

Date: 2026-04-18 Curator: Codex manual synthesis

Scope

Disease: Osteoglophonic dysplasia

Focus for issue #1506: - phenotype section only - add clinically important manifestations backed by exact PMID text - include frequency or onset only when directly supported - remove unsupported obligate-style assertions

Core Phenotype Sources Used

  • PMID:15625620
  • Mutation-confirmed FGFR1 paper with direct abstract support for craniosynostosis, prominent supraorbital ridges, depressed nasal bridge, rhizomelic dwarfism, and nonossifying bone lesions.
  • PMID:16918680
  • Dental follow-up case with direct abstract support for multiple unerupted teeth, several impacted teeth, and lucent jaw/long-bone lesions.
  • PMID:29147600
  • Mutation-confirmed Indian case with direct abstract support for disproportionate short stature, delayed tooth eruption, hypodontia, long-bone nonossifying lesions, and hypophosphatemia.
  • PMID:35148738
  • Four-year follow-up dental case with direct abstract support for frontal bossing and anteverted nares.
  • PMID:38648328
  • 2024 GeneReviews synthesis with PMID-backed abstract text supporting multisuture craniosynostosis, multiple craniofacial features, delayed/failed tooth eruption, gingival overgrowth, osteopenia, and fracture risk.
  • PMID:8958322
  • Review/case report supporting delayed tooth eruption, rib expansion, speech/developmental issues, and rare spontaneous fractures with pseudoarthroses.
  • PMID:8995175
  • Radiology report supporting platyspondyly and epiphyseal dysplasia in addition to nonossifying fibromata.
  • PMID:40260920
  • 2025 phenotype update supporting hypophosphatemia as part of the spectrum and adding overlapping toes as a newly reported feature.

Included in YAML

Phenotypes added or materially strengthened: - multisuture craniosynostosis - disproportionate short-limb short stature - rhizomelia - nonossifying fibromas of the long bones - platyspondyly - epiphyseal dysplasia - osteopenia - pathologic fracture - frontal bossing - prominent supraorbital ridges - depressed nasal bridge - proptosis - hypertelorism - midface retrusion - short nose - anteverted nares - low-set ears - high palate - delayed eruption of teeth - impacted teeth - hypodontia - gingival overgrowth - hypophosphatemia - overlapping toe

Deliberate Omissions / Softening

  • No phenotype frequency: values were retained or added.
  • The available abstracts reliably support disease-phenotype association, but they do not provide direct quantitative frequency bands for these manifestations.
  • Bone age was not modeled.
  • PMID:29147600 reports advanced bone age, while PMID:35148738 reports delayed skeletal maturation, so the current literature is conflicting.
  • Developmental delay / speech delay were not promoted to core phenotypes.
  • PMID:8958322 describes them, but older reports such as PMID:7422392 and PMID:20339250 emphasize normal intelligence or later normal cognition, suggesting variable expression rather than a stable core manifestation.
  • Elevated frontal temperature from PMID:40260920 was not modeled.
  • It appears to be a newly reported observation in two individuals, but HPO grounding is less clear and clinical importance is currently less established than overlapping toes.
  • Short, broad hands and feet from PMID:38648328 were not separately encoded.
  • The review clearly notes distal extremity involvement, but the closest exact HPO fits were less clean than the other added manifestations, so I kept the YAML focused on stronger mappings first.