Van Buchem disease is an autosomal recessive sclerosing bone dysplasia characterized by skeletal hyperostosis, overgrowth of the mandible, and a liability to entrapment of the seventh and eighth cranial nerves. The genetic determinant maps to chromosome 17q12-q21. We refined the critical interval to the < 1-Mb region between D17S2250 and D17S2253 in 15 affected individuals, all of whom shared a common disease haplotype. Furthermore, we report here the identification of a 52-kb deletion located within the interval and encompassing D17S1789 that is 100% concordant with the disorder. Although the deletion itself does not appear to disrupt the coding region of any known or novel gene(s), the closest flanking genes are MEOX1 on the proximal side, and SOST on the distal side of the deletion. MEOX1 is known to be important for the development of the axial skeleton, whereas the SOST gene is the determinant of sclerosteosis, a disorder that shares many features with van Buchem disease, thus raising the possibility that van Buchem disease results from dysregulation of the expression of one or both of these genes.
Copyright 2002 Wiley-Liss, Inc.