Thanatophoric dysplasia is a severe skeletal disorder characterized by a disproportionately small ribcage, extremely short limbs and folds of extra skin on the arms and legs.

Other signs of the disorder include a narrow chest, small ribs, underdeveloped lungs, and an enlarged head with a large forehead and prominent, wide-spaced eyes.

Type I is characterized by extreme rhizomelia, bowed long bones, narrow thorax, a relatively large head, normal trunk length and absent cloverleaf skull.

[2][3] While the condition can be inherited, most cases of thanatophoric dysplasia are caused by new mutations in people with no family history of the disorder.

[citation needed] An unusual head shape called kleeblattschaedel ("cloverleaf skull") can be seen with type 2 thanatophoric dysplasia.

It was reported in 1998 that a 21 year old man with the condition lived in the United States, while two children with TD (aged 10 and 12, a boy and a girl) were known in Germany.