Achondroplasia (ACH) is a genetic bone disorder. It is the most common type of dwarfism. Key features are a large head, short limbs, a narrow chest, and short fingers.
ACH is caused by changes (mutations) in the FGFR3 gene. These changes prevent normal growth. This also leads to shorter and abnormally shaped bones.
This problem can happen in people who do not have any known risk factors.
The gene changes can also be passed through a family, though this is not as common. If a parent has the gene mutations, there is a 50% chance the child will have it.
Things that may raise the risk are:
Problems are often seen at birth. Key features are a large head, short limbs, a narrow chest, and short fingers.
Other problems may be:
A prenatal ultrasound may point to ACH. Genetic testing may be done to confirm it.
ACH may also be suspected during a physical exam at birth. It can be confirmed through x-rays. Rarely, genetic testing may be done if the exam and x-rays are not certain.
There is no cure. The goal of treatment is to manage related health problems. Some options are:
Human growth hormone may help to increase adult height. It is given during childhood.
Some people may need surgery to treat related health problems. Some common options are:
Families may be referred to support groups.
There are no known guidelines to prevent ACH.
Healthy Children—American Academy of Pediatrics
Little People of America
Caring for Kids—Canadian Paediatrics Society
Little People of Ontario
Achondroplasia. EBSCO DynaMed website. Available at:https://www.dynamed.com/condition/achondroplasia. Accessed September 16, 2020.
Achondroplasia. Genetic and Rare Diseases Information Center website. Available at: https://rarediseases.info.nih.gov/diseases/8173/achondroplasia. Accessed September 16, 2020.
Pauli, RM, Legare JM. Achondroplasia. GeneReviews 2018 May 10.
Last reviewed March 2020 by EBSCO Medical Review Board Kari Kassir, MD Last Updated: 9/16/2020