endosteal hyperostosis

van Buchem disease

An autosomal recessive condition (OMIM:239100) characterised by hyperostosis of the skull, mandible, clavicles, ribs and diaphyseal cortices of long bones, as well as a massively enlarged jaw and thickened skull, leading to facial nerve palsy, hearing loss and optic atrophy.
Molecular pathology
van Buchem disease is caused by a genomic deletion of a long-range bone enhancer on chromosome 17q12-q21, which misregulates sclerostin.