Boomerang dysplasia is a lethal form of osteochondrodysplasia known for a characteristic congenital feature in which bones of the arms and legs are malformed into the shape of a boomerang. Death usually occurs in early infancy due to complications arising from overwhelming systemic bone malformations. Osteochondrodysplasias are skeletal disorders that cause malformations of both bone and cartilage.

Reference
Wiki: Boomerang dysplasia