Pseudoachondroplasia is an inherited disorder of bone growth. It was once thought to be related to another disorder of bone growth called achondroplasia, but without that disorder's characteristic facial features. More research has demonstrated that pseudoachondroplasia is a separate disorder.

Mutations in the COMP gene cause pseudoachondroplasia. This gene provides instructions for making a protein that is essential for the normal development of cartilage and for its conversion to bone. Cartilage is a tough, flexible tissue that makes up much of the skeleton during early development. Most cartilage is later converted to bone, except for the cartilage that continues to cover and protect the ends of bones and is present in the nose and external ears.

The exact prevalence of pseudoachondroplasia is unknown; it is estimated to occur in 1 in 30,000 individuals.

Pseudoachondroplasia is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.

Published Date: January 01, 2013
Published By: National Institutes of Health