Your browser does not support javascript:   Search for gard hereSearch for news-and-events here.


Genetic and Rare Diseases Information Center (GARD)

Print friendly version

Craniometaphyseal dysplasia, autosomal dominant

Other Names for this Disease
  • CMD
  • CMDD
  • CMDJ
  • Craniometaphyseal dysplasia Jackson type
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.


Newline Maker

What causes autosomal dominant craniometaphyseal dysplasia?

Autosomal dominant craniometaphyseal dysplasia is caused by mutations in the ANKH gene. The ANKH gene provides instructions for making a protein that is present in bone and transports a molecule called pyrophosphate out of cells. Pyrophosphate helps regulate bone formation by preventing mineralization, the process by which minerals such as calcium and phosphorus are deposited in developing bones. The ANKH protein may have other, unknown functions.[1]

Mutations in the ANKH gene that cause autosomal dominant craniometaphyseal dysplasia may decrease the ANKH protein's ability to transport pyrophosphate out of cells. Reduced levels of pyrophosphate can increase bone mineralization, contributing to the bone overgrowth seen in craniometaphyseal dysplasia. Why long bones are shaped differently and only the skull bones become thicker in people with this condition remains unclear.[1]

Last updated: 8/24/2010

  1. Craniometaphyseal dysplasia. Genetics Home Reference (GHR). 2009; Accessed 8/24/2010.