Sclerosteosis 1, autosomal recessive (SOST1)

(OMIM phenotype number #269500)

Sclerosteosis is a severe autosomal-recessive sclerosing bone dysplasia, characterized by progressive skeletal overgrowth, distortion of the facies, and entrapment of cranial nerves (see also VBD). Sclerosteosis can be distinguished from Van Buchem disease by the presence of syndactyly and a tendency to tall stature. The jaw has an unusually square appearance in this condition. Potentially lethal elevation of intracranial pressure is a frequent complication which has been recognized in children as young as 5 years of age. This disorder is rare and occurs primarily in Afrikaners (South Africa) or others of Dutch ancestry.


SOST gene, 17q21.31 (OMIM gene/locus number #605740)


Symmetric cutaneous syndactyly, excessive height and weight, frontal prominence, midface hypoplasia, vision loss, optic atrophy, deafness, facial palsy, cranial hyperostosis (onset in infancy), occlusion of cranial foramina, hypertelorism, proptosis, convergent strabismus, nystagmus, broad and flat nasal root, prognathism, dental malocclusion, prominent and asymmetric mandible, chronic headaches, intellectual impairment, increased intracranial pressure, nail dysplasia, broad and dense clavicles-ribs, sclerotic scapulae, sclerotic vertebral endplates and pedicles, sclerotic pelvis, cortically dense long tubular bones, and lack of diaphyseal modeling.


  1. Hamersma H, Gardner J, Beighton P. The natural history of sclerosteosis. Clin Genet. 2003 Mar;63(3):192-7
  2. Balemans W, Van Den Ende J, Freire Paes-Alves A, et al. Localization of the gene for sclerosteosis to the van Buchem disease-gene region on chromosome 17q12-q21. Am J Hum Genet. 1999 Jun;64(6):1661-9.
  3. Beighton P, Davidson J, Durr L, Hamersma H. Sclerosteosis - an autosomal recessive disorder. Clin Genet. 1977 Jan;11(1):1-7.
  4. Masi L, Agnusdei D, Bilezikian J et al. Taxonomy of rare genetic metabolic bone disorders. Osteoporos Int. 2015 Jun 13.