Lethal Osteodysplasia of the Micromelic Type

Lethal osteodysplasia of the micromelic type is represented by those syndromes characterized by micromelic dwarfism that have the lethal attribute, because they lead to death at birth or in the perinatal period or in the first months of life. The fetal malformations, in which the skeletal dysplasia sign appears and which have a very bad prognosis, are, however, many others: for example, trisomy 13, trisomy 18, homozygous achondroplasia, and many others, but, in this chapter, only those bone dysplasias in which the characteristic feature is extremely severe micromelia are described.