Thanatophoric dysplasia (TD) is a severe and generally lethal skeletal dysplasia presenting in the prenatal period and characterized by micromelia, macrocephaly, narrow thorax, and distinctive facial features. It includes TD, type 1 (TD1) and TD, type 2 (TD2) (see these terms), that can be differentiated from each other by femur and skull shape.

Digits that appear disproportionately short compared to the hand/foot. The word brachydactyly is used here to describe a series distinct patterns of shortened digits (brachydactyly types A-E). This is the sense used here.