Achondroplasia is a genetic disorder that affects bone growth and results in dwarfism. It is caused by mutations in the FGFR3 gene, which provides instructions for making a protein involved in the development and maintenance of bone and brain tissue.
In people with achondroplasia, the mutations in the FGFR3 gene cause overactivity of the protein it produces, leading to impaired bone growth in the arms, legs, and skull. This results in characteristic features such as short stature, disproportionately short limbs, a prominent forehead, and a flattened bridge of the nose. Individuals with achondroplasia may also have a spinal curvature (scoliosis) and a range of other skeletal abnormalities.
Achondroplasia is usually diagnosed by physical examination and confirmed with genetic testing. Treatment is primarily focused on managing symptoms, and may involve surgical interventions to address spinal and joint problems, as well as physical therapy and pain management.
Achondroplasia is inherited in an autosomal dominant pattern, meaning that a person only needs to inherit one copy of the mutated gene from either parent to develop the disorder. However, about 80% of cases are the result of new mutations that occur in the affected individual and are not inherited from either parent.