Learn About Achondroplasia
View Main Condition: Short Stature (Growth Disorders)
Achondroplasia is a disorder of bone growth that causes the most common type of dwarfism.
Dwarf; Dwarfism; Achondroplastic dwarfism
Achondroplasia is one of a group of conditions called chondrodystrophies or osteochondrodysplasias. These rare genetic disorders cause problems with the development of bone, cartilage, and connective tissue.
Achondroplasia is caused by a variant in the fibroblast growth factor receptor 3 (FGFR3) gene. This prevents bone growth and mainly affects the long bones in the arms and legs. People with achondroplasia have a short stature, with an average height under 4 feet 6 inches (137 centimeters).
Achondroplasia may be inherited as an autosomal dominant trait. This means that if a child gets the variant gene from one parent, the child will have the disorder. If one parent has achondroplasia, the infant has a 50% chance of inheriting the disorder. If both parents have the condition, the infant's chance of being affected increases to 75%.
However, most cases (about 80%) appear as spontaneous variants. This means that two parents without achondroplasia may give birth to a baby with the condition.
Achondroplastic dwarfism results in the following:
- Unusually large head
- Large forehead and flat bridge of the nose
- Crowded or crooked teeth
- Short stature (well below the average height for a person of the same age and sex)
- Average size trunk with short arms and legs (especially the upper arms and thighs)
- Bowed legs
- Limited range of motion of the elbows
- Spine curvatures called kyphosis and lordosis
- Short fingers with an extra space between the ring and middle finger (trident hand)
- Decreased muscle tone in infants
Almost all people with achondroplasia have normal intelligence and will have a normal lifespan. Children with the disorder may develop at a slower rate than other children the same age.
There is no specific treatment for achondroplasia. The disorder may cause certain health conditions, which need to be treated when they cause problems.
- Obstructive sleep apnea can be treated with surgery and continuous positive airway pressure (CPAP) devices.
- Children who have recurring ear infections may need surgery to place tubes in their eardrums.
- Obesity can put extra strain on the body, so learning to eat a healthy diet and avoid weight gain from a young age is important.
- Bracing may be needed to help correct upper spine curvature (kyphosis).
- Hydrocephalus can be treated with surgery (ventriculoperitoneal shunting).
- Physical therapy can help if gait is affected due to lordosis (curving of the lower back).
- Corrective surgery may be needed if there are problems walking due to bowed legs.
- Spine surgery may be needed to relieve pressure on the spinal cord due to spinal stenosis or spinal cord compression at the base of the skull.
Vosoritide (Voxzogo) is a new medicine approved for use in children age 5 years and older who are still growing. This once daily injection may slightly improve bone growth.
Children and adults will need adaptations to their home, school, and work environment to accommodate a shorter stature.
Rubenstein Child Health Building
Dr. Julie Hoover-Fong is a Professor of Genetic Medicine and Pediatrics and Director of the Greenberg Center for Skeletal Dysplasias at Johns Hopkins University. Dr. Hoover-Fong holds a bachelor’s degree in Human Nutrition from The Ohio State University, where she also completed her medical degree. She received her Ph.D. in the Graduate Training Program in Clinical Investigation at the Johns Hopkins University School of Medicine and Bloomberg School of Public Health. Dr. Hoover-Fong completed a pediatric internship and residency at Washington University in St. Louis and a fellowship in medical genetics at Johns Hopkins University in Baltimore. She joined the Johns Hopkins University faculty in 2002 and progressed to Professor of Genetic Medicine and Pediatrics in 2019. She practices and oversees the clinical operations, research and educational ventures for the patients, families and healthcare providers served by the Greenberg Center. Her clinical team develops and improves diagnostic and treatment guidelines for comprehensive care of patients with all types of bone conditions including dwarfism, orofacial clefting, craniosynostosis and more. Dr. Hoover-Fong also mentors and teaches medical students, residents and genetic medicine trainees. As an active clinical researcher, Dr. Hoover-Fong is the Principal Investigator of multiple global clinical trials for achondroplasia, the first multi-center, investigator-initiated natural history study for achondroplasia, and multiple clinical studies for patients with orofacial clefting, hypophosphatasia and other conditions. She is also a co-investigator on the ELSI and Phenotype Review Committees for the Mendel Project, a whole exome sequencing venture to identify the genetic cause of Mendelian conditions. From an institutional service perspective, Dr. Hoover-Fong serves on the Johns Hopkins Associate Professor Promotions Committee and the Advisory Committee for the Graduate Training Program in Clinical Investigation. She serves on the Medical Advisory Board of the Little People of America, is a member of the Miller-Coulson Academy of Clinical Excellence at Johns Hopkins University and is a charter member of the International Skeletal Dysplasia Management Consortium, publishing best practice guidelines for patients with skeletal dysplasias. Dr. Hoover is rated as an Elite provider by MediFind in the treatment of Achondroplasia. Her top areas of expertise are Achondroplasia, Rhizomelic Syndrome, Spondyloepimetaphyseal Dysplasia Strudwick Type, Adenoidectomy, and Myringotomy.
Ravi Savarirayan practices in Parkville, Australia. Mr. Savarirayan is rated as an Elite expert by MediFind in the treatment of Achondroplasia. His top areas of expertise are Achondroplasia, Acanthosis Nigricans, Chondrodystrophy, and Schwartz-Jampel Syndrome.
Michael Bober is a Medical Genetics provider in Wilmington, Delaware. Dr. Bober is rated as an Elite provider by MediFind in the treatment of Achondroplasia. His top areas of expertise are Microcephalic Osteodysplastic Primordial Dwarfism Type 2 (MOPD2), Microcephalic Osteodysplastic Primordial Dwarfism Type 1 (MOPD1), Achondroplasia, Osteotomy, and Adenoidectomy. Dr. Bober is currently accepting new patients.
Being physically different from others can be difficult for children who may be made fun of or bullied. Even in adulthood, people with dwarfism may be stared at or treated differently. Connecting with others affected by the disorder can help children and their families feel less alone.
More information and support for people with achondroplasia and their families can be found at:
- Human Growth Foundation - www.hgfound.org/support-groups
- Little People of America - www.lpaonline.org
- The MAGIC Foundation - www.magicfoundation.org
Adult heights typically are 46 to 57 inches (1.17 to 1.45 meters) for men and 44 to 54 inches (1.12 to 1.37 meters) for women. Intelligence is in the normal range. Infants who receive the abnormal gene from both parents do not often live beyond a few months.
People with achondroplasia should have regular checkups throughout their life, as the condition can cause other health problems. Most problems can be treated.
Complications that may develop include:
- Breathing problems from a small upper airway and from pressure on the area of the brain that controls breathing
- Lung problems from a small ribcage
- Narrowing of the spinal column (spinal stenosis)
- Pressure on the spinal column at the base of the neck
- Hydrocephalus
- Back pain and joint problems
If there is a family history of achondroplasia and you plan to have children, you may find it helpful to speak to your health care provider.
Genetic counseling may be helpful for prospective parents when one or both have achondroplasia. However, because achondroplasia most often develops spontaneously, prevention is not always possible.
Summary: The purpose of this study is to evaluate the safety, tolerability, and identify potentially effective dose(s) of TYRA-300 in children with achondroplasia with open growth plates.
Summary: The purpose of this clinical trial is to evaluate efficacy and safety of once weekly subcutaneous (SC) doses of navepegritide 100 μg/kg compared to placebo (inactive drug) in adolescents aged 12 to 18 years with Achondroplasia. What will be measured is Annualized Growth Velocity after a 52-week treatment period.
Published Date: October 01, 2025
Published By: Charles I. Schwartz, MD, FAAP, Clinical Assistant Professor of Pediatrics, Regional Medical Director of Penn Medicine Primary and Specialty Care, Perelman School of Medicine at the University of Pennsylvania, General Pediatrician at PennCare for Kids, Phoenixville, PA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
Albokhari D, Hoover-Fong JE. Disorders involving transmembrane receptors. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 737.
Krakow D. Fibroblast growth factor receptor 3 (FGFR3) disorders: thanatophoric dysplasia, achondroplasia, and hypochondroplasia. In: Copel JA, D'Alton ME, Feltovich H, et al, eds. Obstetric Imaging: Fetal Diagnosis and Care. 3rd ed. Philadelphia, PA: Elsevier; 2026:chap 80.
National Organization for Rare Disorders website. Achondroplasia. rarediseases.org/rare-diseases/achondroplasia/. Updated November 17, 2023. Accessed October 9, 2025.
Savarirayan R, Hoover-Fong J, Yap P, Fredwall SO. New treatments for children with achondroplasia. Lancet Child Adolesc Health. 2024;8(4):301-310. PMID: 38485412 pubmed.ncbi.nlm.nih.gov/38485412/.