Definition:

Sclerosteosis is rare sclerosing bone dysplasias inherited in an autosomal recessive manner. The main clinical features are enlargement of the jaw and facial bones, which can lead to secondary findings such as facial distortion, increased intracranial pressure often resulting in headaches, and entrapment of the cranial nerves. Other findings include syndactyly and tall stature. This disease is due to loss-of-function mutations in the SOST gene, a protein that binds to LRP5/6 and antagonizes Wnt signaling. Recently, mutations in the LRP4 gene, coding for a Wnt signaling coreceptor, have been found in patients with sclerosteosis.