Osteoglophonic dysplasia is a rare disorder; its prevalence is unknown. Only about 15 cases have been reported in the medical literature.

Osteoglophonic dysplasia is caused by mutations in the FGFR1 gene, which provides instructions for making a protein called fibroblast growth factor receptor 1. This protein is one of four fibroblast growth factor receptors, which are related proteins that bind (attach) to other proteins called fibroblast growth factors. The growth factors and their receptors are involved in important processes such as cell division, regulation of cell growth and maturation, formation of blood vessels, wound healing, and embryonic development. In particular, they play a major role in skeletal development.

The FGFR1 protein spans the cell membrane, so that one end of the protein remains inside the cell and the other end projects from the outer surface of the cell. When a fibroblast growth factor binds to the part of the FGFR1 protein outside the cell, the receptor triggers a cascade of chemical reactions inside the cell that instruct the cell to undergo certain changes, such as maturing to take on specialized functions. The FGFR1 protein is thought to play an important role in the development of the nervous system. This protein may also help regulate the growth of long bones, such as the large bones in the arms and legs.

FGFR1 gene mutations that cause osteoglophonic dysplasia change single building blocks (amino acids) in the FGFR1 protein. The altered FGFR1 protein appears to cause prolonged signaling, which promotes premature fusion of bones in the skull and disrupts the regulation of bone growth in the arms and legs.