Overview
Eiken syndrome is an extremely rare inherited bone disorder that affects how the skeleton grows and develops. It is also sometimes referred to as 'Eiken skeletal dysplasia.' The condition is caused by changes (mutations) in the PTH1R gene, which gives instructions for making a protein that helps regulate bone and cartilage growth. When this gene does not work properly, the bones develop abnormally, leading to a condition called delayed bone maturation — meaning the bones look much younger on X-ray than the person's actual age. The main features of Eiken syndrome include very delayed hardening (ossification) of the bones, unusual bone shapes, and changes in the growth plates — the areas at the ends of bones where growth happens in children. People with this condition may have short stature, joint problems, and abnormal bone structure throughout the body, including the spine, pelvis, and limbs. The hands and feet may also look different. Because Eiken syndrome is so rare, treatment is focused on managing symptoms rather than curing the underlying cause. Care typically involves a team of specialists including bone doctors, geneticists, and physical therapists. There is currently no approved drug that targets the root cause of the disease. Management aims to support mobility, reduce pain, and monitor bone health over time.
Key symptoms:
Very delayed bone hardening (ossification) compared to ageShort stature or slower than normal growthAbnormal bone shapes seen on X-rayChanges in the growth plates of bonesUnusual appearance of the pelvis and hip bonesAbnormal spine shape or structureDifferences in the shape of hands and feetJoint stiffness or limited range of motionMild to moderate skeletal deformitiesBones that appear much younger than the person's actual age on imaging
Clinical phenotype terms (23)— hover any for plain English
Autosomal recessive
Passed on when both parents carry the same gene change; often skips generations
Childhood
Begins in childhood, roughly ages 1 to 12
Treatments
No FDA-approved treatments are currently listed for Eiken syndrome.
View clinical trials →Clinical Trials
View all trials with filters →No actively recruiting trials found for Eiken syndrome at this time.
New trials open frequently. Follow this disease to get notified.
Specialists
View all specialists →No specialists are currently listed for Eiken syndrome.
Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to Eiken syndrome.
Community
No community posts yet. Be the first to share your experience with Eiken syndrome.
Start the conversation →Latest news about Eiken syndrome
No recent news articles for Eiken syndrome.
Follow this condition to be notified when news becomes available.
Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.What specific mutations were found in the PTH1R gene, and what do they mean for my child's health?,How often should we have X-rays or other imaging to monitor bone development?,What physical activities are safe, and are there any we should avoid?,Should other family members be tested for PTH1R mutations?,Are there any clinical trials or research studies we could participate in?,What signs should prompt us to seek urgent medical attention?,Can you refer us to a center that specializes in rare skeletal dysplasias?
Common questions about Eiken syndrome
What is Eiken syndrome?
Eiken syndrome is an extremely rare inherited bone disorder that affects how the skeleton grows and develops. It is also sometimes referred to as 'Eiken skeletal dysplasia.' The condition is caused by changes (mutations) in the PTH1R gene, which gives instructions for making a protein that helps regulate bone and cartilage growth. When this gene does not work properly, the bones develop abnormally, leading to a condition called delayed bone maturation — meaning the bones look much younger on X-ray than the person's actual age. The main features of Eiken syndrome include very delayed hardening
How is Eiken syndrome inherited?
Eiken syndrome follows a autosomal recessive inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Eiken syndrome typically begin?
Typical onset of Eiken syndrome is childhood. Age of onset can vary across affected individuals.