What causes Achondroplasia?
Mutations in the FGFR3 gene cause achondroplasia. The FGFR3 gene provides instructions for making a protein that is involved in the development and maintenance of bone and brain tissue. Two specific mutations in the FGFR3 gene are responsible for almost all cases of achondroplasia. Researchers believe that these mutations cause the protein to be overly active, which interferes with skeletal development and leads to the disturbances in bone growth seen with this disorder.
Achondroplasia is inherited in an autosomal dominant pattern so one copy of the altered gene in each cell is sufficient to cause the disorder. In the majority of cases, the parents do not carry the mutation, and the mutation occurs spontaneously in the child.
Individuals who inherit two altered copies of this gene typically have very severe problems with bone growth, and are usually stillborn or die shortly after birth from respiratory failure. </s>