What gene change causes achondroplasia?
Changes in the FGFR3 gene can lead to achondroplasia. Around 99% of people with achondroplasia have one of two specific genetic changes ("mutations") in the FGFR3 gene. These two gene changes in FGFR3 that cause achondroplasia are known as: c.1138G>A (p.Gly380Arg) and c.1138G>C (p.Gly380Arg).
More Causes Content
What happens because of a change to the FGFR3 gene?
People with achondroplasia have poor cartilage to bone conversion. Cartilage is the bendable, but strong material that makes up your ears and the tip of your nose. When babies are first developing, much of the skeleton is initially made of cartilage. This cartilage then needs to transform into bone in a process named ossification. The FGFR3 gene codes for making a protein that is involved in the ossification process. When someone has a genetic change in the FGFR3 gene causing achondroplasia, ossification does not occur at the usual rate. This process is especially slowed in the legs and the arms. This leads to people with achondroplasia having shorter arms and legs than the average person. To learn more about how the FGFR3 gene causes achondroplasia, refer to a reliable website such as Genetics Home Reference.
Does anything make the symptoms of achondroplasia worse?
There is not anything in particular that makes the symptoms of achondroplasia worse, but there are some precautions that should be taken to prevent injury. For example, children with achondroplasia are at higher risk to have a spinal cord injury, particularly at the craniocervical junction (skull to spine connection on the spinal cord). Avoiding certain activities, like contact sports, trampoline bouncing, diving, and gymnastics (particularly the vault) can reduce risk of these types of injury. To learn more about how to avoid injuries for individuals with achondroplasia, refer to a reliable source such as the Gene Review on achondroplasia.