"VBD is a homozygous recessive disorder. A deletion affecting the SOST gene alters expression of sclerostin in osteoblasts, causing failure of inhibition of osteoblastic bone formation 1."
"VBD is typified by diffuse sclerosis and hyperostosis of the skeleton, but most prominently observed in the cranial and tubular bones. Because of this, complications include those secondary to the bony enlargement, including facial distortions, cranial nerve compression, vision and hearing impairment."