Lethal osteosclerotic bone dysplasia (Q98927)

Lethal osteosclerotic bone dysplasia is defined by generalised osteosclerosis with periosteal bone formation, characteristic facial dysmorphism, brain abnormalities including intracerebral calcifications, and neonatal lethal course. The cranial features are a wide anterior fontanelle, expressed proptosis with everted lower eyelids, severely depressed nasal bridge, small nose, low-set ears, and severe midface hypoplasia leading to choanal atresia. The mouth is usually triangular, gum hypertrophy is expressed, and there may be natal teeth and cleft palate/uvula.