Thanatophoric dysplasia is a severe skeletal disorder characterized by extremely short limbs and folds of extra (redundant) skin on the arms and legs. Other features of this condition include a narrow chest, short ribs, underdeveloped lungs, and an enlarged head with a large forehead and prominent, wide-spaced eyes.

Mutations in the FGFR3 gene cause thanatophoric dysplasia. Both types of this condition result from mutations in the FGFR3 gene. This gene provides instructions for making a protein that is involved in the development and maintenance of bone and brain tissue. Mutations in this gene cause the FGFR3 protein to be overly active, which leads to the severe disturbances in bone growth that are characteristic of thanatophoric dysplasia. It is not known how FGFR3 mutations cause the brain and skin abnormalities associated with this disorder.

This condition occurs in 1 in 20,000 to 50,000 newborns. Type I thanatophoric dysplasia is more common than type II.

Thanatophoric dysplasia is considered an autosomal dominant disorder because one mutated copy of the FGFR3 gene in each cell is sufficient to cause the condition. Virtually all cases of thanatophoric dysplasia are caused by new mutations in the FGFR3 gene and occur in people with no history of the disorder in their family. No affected individuals are known to have had children; therefore, the disorder has not been passed to the next generation.

Published Date: October 01, 2012Published By: National Institutes of Health