Sclerosteosis is an autosomal recessive disorder characterized by bone overgrowth.
[1] It is a rare disorder that is most prominent in the Afrikaner population in South Africa (40 patients), but there have also been cases of American and Brazilian families.
[1] Sclerosteosis is caused by mutations in the SOST gene that encodes the sclerostin protein.
Wnt signalling results in increased osteoblast activity and RANKL synthesis.
Sclerostin therefore increases bone formation by indirectly inhibiting RANKL synthesis and thus osteoclast activation.