Patients appear normal at birth, but multiple
compression fractures of the long bones are noted soon thereafter, followed
by extensive demineralization with recurrent diaphyseal fractures of the
weight-bearing bones before the first birthday. Short stature, kyphosis, and
scoliosis are other skeletal features. Facial abnormalities may include
facial structural asymmetry, development of marked frontal and temporal
bossing, hypertelorism, short midface, micrognathia, depressed premaxillary
region, shallow orbits with ocular proptosis, blue sclerae, dental
anomalies, and craniosynostosis of the coronal and frontal sutures with
rapidly progressive hydrocephalus. Normal neurologic development has been
reported, but anomalies of crying, voice, and gait and generalized hypotonia
are common. Osteopenia and hypercalcemia is frequent. Hydrops fetalis has
been described in one case.