Article Translations: (Spanish)
May also be called: Achondroplastic Dwarfism; Skeletal Dysplasia
Achondroplasia (ay-kon-druh-PLAY-zhee-uh) is a genetic disorder that that limits bone growth. It’s the most common cause of dwarfism (short stature).
As a baby develops in the womb, most of the skeleton is made up of a tough, flexible tissue called cartilage. Normally, cartilage turns into bone by a process called ossification.
With achondroplasia, the body has a problem turning cartilage into bone, especially in the long bones of the arms and legs. This causes shorter bones —making kids shorter in height — and can also lead to a large head with a wide forehead. It can also cause knock-knees, bow-legs, or a curved lower back (lordosis or kyphosis).
Kids with this condition are more likely to develop hydrocephalus (fluid collecting around the brain), obesity, spinal stenosis (narrowing of the spinal canal), and other health conditions.
Regularly seeing a doctor or specialist is important for kids with achondroplasia to make sure they get the care they need to stay healthy.
All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.
Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.
© 1995-2025 KidsHealth ® All rights reserved. Images provided by iStock, Getty Images, Corbis, Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart.com