The boneless neonate: a severe form of achondrogenesis type I.

We report a case of a severe form of achondrogenesis type I. Prenatal ultrasonography showed a micromelic fetus; bony structures could not be identified. Postnatal radiographs revealed some foci of ossification in the ossa ilia, the clavicles, the upper and the lower jaw and the base of the skull. The long bones, the vertebral column and the ribs were not visible. The diagnosis was established by histologic examination of the growth plates.