Finger bones are undermodeled, with erosions and loss of joint space. Overgrowth and distortion of the mandible and brow become evident in mid-childhood. Subsequently, entrapment of the cranial nerves leads to facial palsy and deafness. Life span is not compromised, stature is normal, and the bones are not fragile. Major x-ray features are widening and sclerosis of the calvaria, cranial base, and mandible.
Endosteal thickening is present in the diaphyses of the tubular bones.
Surgical decompression of entrapped nerves may be helpful. Sclerosteosis is an autosomal recessive condition that is most prevalent in the Afrikaner population of South Africa. Overgrowth and sclerosis of the skeleton, particularly of the skull, develop in early childhood. Height and weight are often excessive, and deafness and facial palsy due to cranial nerve entrapment may be a presenting feature. Distortion of the facies, apparent by age 10, eventually becomes severe.