Micromelic bone dysplasia with cloverleaf skull.

Micromelic bone dysplasia with cloverleaf skull is a well-described entity with short, straight tubular bones, hydrocephalus and cloverleaf deformity of the skull, narrow chest and platyspondyly. A further two unrelated patients are presented, in whom the shape of the head varied. Both cases also showed a narrow foramen magnum, hypoplastic cerebellum, atrial septal defect, hypoplastic adrenals, and ureteric malformations. The findings in the skeleton show similarities to other types of generalised bone dysplasias but are distinguishable from these. This well-defined bone dysplasia should probably be regarded as a separate entity. Visceral malformations may be associated.