New Phenotypic Features in FGFR1-Related Osteoglophonic Dysplasia

Area of Science:

• Genetics and Skeletal Biology
• Rare Genetic Disorders

Background:

• Osteoglophonic dysplasia (OGD) is a rare skeletal dysplasia characterized by specific variants in the Fibroblast Growth Factor Receptor 1 (FGFR1) gene.
• FGFR1 plays a crucial role in osteogenesis, particularly in the axial and craniofacial skeleton.

Observation:

• Key features of OGD include craniosynostosis, craniofacial dysmorphism, impacted teeth, rhizomelic shortening, and nonossifying fibromas.
• Patients may exhibit hypophosphatemia secondary to elevated FGF23 levels.
• Two patients with the c.1141T > C FGFR1 variant [p.(Cys381Arg)] were initially diagnosed with Pfeiffer syndrome, presenting with classic OGD symptoms and novel findings like elevated frontal temperature and overlapping toes.

Findings:

• The study identifies a specific FGFR1 variant (c.1141T > C) associated with Osteoglophonic dysplasia.
• The clinical presentation in the reported cases expands the known phenotype of OGD, including previously undocumented signs.
• Differential diagnosis between OGD and similar skeletal disorders like Pfeiffer syndrome is highlighted as critical.

Implications:

• Accurate diagnosis of OGD is essential for appropriate patient management and genetic counseling.
• Recognizing the expanded clinical phenotype aids in distinguishing OGD from other craniosynostotic syndromes.
• Further research into FGFR1-related skeletal dysplasias can improve understanding and treatment strategies.