Osteoglophonic dysplasia

Osteoglophonic dysplasia is an autosomal dominant disorder caused by activating mutations of the FGFR1 gene. The clinical feature result from abnormal bone growth and include craniofacial abnormalities and dwarfism. The term osteoglophonic stems from x-ray images in which bone appears as hollowed out.

Clinical Findings

Clinical features include:

• craniosynostosis (tower-shapped skull)
• prominent forehead (frontal bossing)
• widely spaced eyes (hypertelorism)
• flattening of the bridge of the nose and of the middle of the face (midface hypoplasia)
• a large tongue (macroglossia)
• protruding jaw (prognathism)
• short neck
• no visible teeth (clinical anodontia)
• gums overgrown (hypertrophic gingiva)
• failure to thrive
• short, bowed legs and arms
• short in stature
• flat feet
• short, broad hands and fingers Despite the prominent skull abnormalities intelligence seems not to be affected.

Symptoms

Dysmorphism
	Dysmorphisms are mainly craniofacial.
Growth retardation
	Dwarfism results from disturbed bone growth and short limbs.
Hypophosphatemia
	Hypophosphatemia results from hyperphosphaturia.
Hyperphosphaturia
	Hyperphosphaturie is caused by disrupted intracellular signaling in proximal tubulus cells.

Systematic

Hypophosphatemic bone and kindney disease
	Disorders of the renal phosphate transporters
	FGF23-induced hypophosphatemic rickets
	Fanconi-type hypophosphatemic rickets
	Hypophosphatemic rickets with hyperparathyroidism
	Osteoglophonic dysplasia
		FGFR1
	Raine syndrome
	X-linked dominant hypophosphatemic rickets

References:

1.	Beighton P et al. (1980) Osteoglophonic dwarfism.

2.	Riminucci M et al. (2003) FGF-23 in fibrous dysplasia of bone and its relationship to renal phosphate wasting.

3.	White KE et al. (2005) Mutations that cause osteoglophonic dysplasia define novel roles for FGFR1 in bone elongation.

4.	Farrow EG et al. (2006) Extended mutational analyses of FGFR1 in osteoglophonic dysplasia.

5.	Scriver CR et al. (1969) Pseudohypophosphatasia.

6.	Keats TE et al. (1975) Craniofacial dysotosis with fibrous metaphyseal deffects.

7.	Greenberg F et al. (1990) Osteoglophonic dysplasia.

8.	None (1989) Osteoglophonic dysplasia.

9.	Santos H et al. (1988) Osteoglophonic dysplasia: a new case.

10.	Kelley RI et al. (1983) Osteoglophonic dwarfism in two generations.

11.	OMIM.ORG article Omim 166250

12.	Wikipedia article Wikipedia EN (Dwarfism)