Definition
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.
Risk Factors
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.
Symptoms
Problems are often seen at birth. Key features are a large head, short limbs, a narrow chest, and short fingers.
Other problems may be:
- Short stature—adult height will be 4 to 4½ feet
- Bowlegs
- Short toes
- Underdeveloped parts of the face
- Arms that may not be fully straight at the elbow
- An excessive lower back curve
Diagnosis
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.
Treatment
There is no cure. The goal of treatment is to manage related health problems. Choices are:
- Medicine, such as human growth hormone to increase adult height
- Surgery to treat health problems, such as:
- Spinal fusion to connect spinal bones to make them more stable
- Laminectomy to remove parts of spinal bones to ease pressure on the spinal cord
- Osteotomy to repair severe bowlegs
- Bone lengthening to cut and divide a bone to encourage more growth
- Counseling and support groups
RESOURCES
Healthy Children—American Academy of Pediatrics http://www.healthychildren.org
Little People of America http://www.lpaonline.org
CANADIAN RESOURCES
Caring for Kids—Canadian Paediatrics Society http://www.caringforkids.cps.ca
Little People of Ontario http://www.lpo.on.ca
References
Achondroplasia. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/achondroplasia. Accessed October 29, 2020.
Achondroplasia. Genetic and Rare Diseases Information Center website. Available at: https://rarediseases.info.nih.gov/diseases/8173/achondroplasia. Accessed October 29, 2020.
Pauli RM, Legare JM. Achondroplasia. GeneReviews 2018 May 10.
Revision Information
- Reviewer: EBSCO Medical Review Board James P. Cornell, MD
- Review Date: 09/2020
- Update Date: 04/28/2021