Thanatophoricdysplasia (TD) isanosteochondrodysplasiaalwayslethalintheneonatalperiod. Thevastmajorityofcasesareduetodenovomutations. Itisdividedintotwotypes: ashortcurvedfemurcharacterizestype 1, whileastraighterfemurwithcloverleafskullcharacterizestype 2. Inthanatophoricdysplasiathelimbsareveryshort. Theribcageissmall. Thevertebralbodiesofthespinearegreatlyreducedinheightwithwidespacesbetwee...

Thanatophoric dysplasia type I (TDI) is a neonatal lethal skeletal dysplasia caused by several mutations in the extracellular domain of fibroblast growth factor receptor 3. These mutations occur either in the Ig2-Ig3 linker domain or in the extracellular juxtamembrane domain, and all involve mutation of the wild-type residue to Cys. In all cases, the presence of the mutant Cys residue allows th...