What is achondroplasia?

Achondroplasia is a rare, genetic condition that affects bone growth. It is the most common type of skeletal dysplasia. Achondroplasia causes bone growth to slow down, especially in the long bones of the arms and legs. This causes short stature, shortened limbs, and other distinctive features.1

Definitions of key terms can be found in the glossary

80% of people with achondroplasia have no family history of the condition1

What causes achondroplasia?

Achondroplasia is caused by variants in the fibroblast growth factor receptor 3 (FGFR3) gene. FGFR3 plays a key role in regulating bone growth.1,2

Achondroplasia occurs in about 1 in 25,000 births. The variants that cause achondroplasia can occur either by chance or from being passed down by a parent with the condition.1

Most of the time, the variant occurs in families with no prior history of achondroplasia. In families where one parent has the condition, there is a 50% chance that the variant will be passed down to the child.1

Bone growth plate

Enlarge image

Chondrocytes are a type of cell responsible for bone and cartilage formation. They are essential for the development of the skeletal system.2,3

Chondrocytes contain a type of protein called FGFR3, which can exist in either an “on” or “off” state. When “on”, FGFR3 helps to slow bone growth.2,3

In people with achondroplasia, FGFR3 becomes overactive. This constant “on” state reduces bone growth and leads to the common features of achondroplasia.1

Medical impacts of achondroplasia

A varied journey for individuals

The way bones grow in people with achondroplasia can lead to specific medical complications and challenges. Multiple systems in the body can be affected and symptoms may vary at different stages of life.4-6 Complications that may occur are shown in the table below.

Individuals with achondroplasia should have regular check-ups by an experienced, multidisciplinary healthcare team. Some complications may improve on their own, while others may require treatment or surgery. Some children may benefit from early intervention.6 Learning about the complications that may occur can help individuals and families feel prepared and get the care needed.

Talk to a member of your healthcare team for guidance on your care plan

Medical impacts of achondroplasia across many stages of life





ENT, respiratory, dental 4-6

Sleep apnea – slowed or repeated stopping of breathing during sleep

Dental complications – crowded or crooked teeth, narrow palate, open bite or underbite

Recurrent ear infections – may lead to delayed speech or hearing loss

Respiratory problems – upper airway obstructions





Neurologic 4-6

Hypotonia – poor muscle tone

Foramen magnum stenosis – narrowing of the opening at the base of the skull, which can affect breathing or develop into other complications

Spinal stenosis – narrowing of the lower spinal cord, which may cause pain and other complications





Orthopedic 4-5

Hypermobility of joints

Kyphosis – outward curving (rounding) of the upper back

Lordosis – inward curving (arching) of the lower back

Genu varum – bowed legs

Chronic pain – widespread joint and muscle pain

Metabolic conditions – obesity





Definitions of these terms can be found in the glossary

Learn more about the diagnosis and management of achondroplasia

Living well with achondroplasia

Impacts on daily activities

People with achondroplasia generally live healthy, active, and independent lives. However, some activities can be challenging due to the way that bones develop in achondroplasia.5

Learning about adaptations and options for support can enhance independence and well-being

Daily activities that may be impacted by achondroplasia7

Quality of life

The experience of living with achondroplasia is different for each individual and each family. Many factors, such as functional limitations, social stigma, or emotions, can affect quality of life.7-9

Adaptations and tools, such as step stools and personal care devices, can support independence in daily activities.1 Psychological support from healthcare professionals as well as social support from family members, peers, and advocacy groups may enhance well-being.4,6


Learn more about the impact of living with achondroplasia

Daily impacts for children and parents

Most commonly reported challenges

Unique experience of living well

Looking for more information or advocacy resources?

Learn more about our research and clinical studies


  1. Pauli RM. Achondroplasia: a comprehensive clinical review. Orphanet J Rare Dis. 2019;14(1):1.
  2. Horton WA and Degnin CR. FGFs in endochondral skeletal development. Trend Endocrinol Metab. 2009;20(7):341-348.
  3. Ornitz DM and Legeai-Mallet L. Achondroplasia: Development, pathogenesis, and therapy. Dev Dyn. 2017;246(4):291-309.
  4. Hoover-Fong J et al. Lifetime impact of achondroplasia: Current evidence and perspectives on the natural history. Bone. 2021;146:115872.
  5. Unger S et al. Current care and investigational therapies in achondroplasia. Curr Osteoporos Rep. 2017;15(2):53-60.
  6. Savarirayan R et al. International Consensus Statement on the diagnosis, multidisciplinary management and lifelong care of individuals with achondroplasia. Nat Rev Endocrinol. 2022;18(3):173-189.
  7. Mathias D et al. Qualitative research in children with achondroplasia and parents of children with achondroplasia: medical challenges and impacts. Poster presented at: Endocrine Society, June 11 2022, Atlanta, GA.
  8. Pfeiffer KM et al. Assessing physical symptoms, daily functioning, and well-being in children with achondroplasia. Am J Med Genet A. 2021;185(1):33-45.
  9. Ireland PJ et al. Optimal management of complications associated with achondroplasia. Appl Clin Genet. 2014;7:117-125.