platyspondyly

Spondyloepiphyseal dysplasia

Disproportionate dwarfism with a short trunk

Problems with dwarfism, spine, vision and hearing

Primary involvement of vertebrae & epiphyseal centres of limbs

Resulting short-trunk dwarfism

- Limb are short, but trunk is even shorter

(cf Metaphyseal Chondrodysplasia - Short limbed Dwarf)

Dysproportionate dwarfism

- short limbs and normal trunk

- rhizomelic

DDx

- physeal dysplasia (SED, MED)

FGF Receptor 3

- point mutation

- decreases endochondral ossification

- normal intramembraneous ossification

- FGFR3 is found in all pre-bone cartilage & in CNS

- FGFR3 inhibits chondrocyte proliferation in the proliferative zone