Overview
"Syndromes with synostoses of limbs" is an obsolete (no longer actively used) grouping term from the Orphanet rare disease classification system. It was used to describe a collection of rare genetic conditions in which bones in the arms, legs, hands, or feet become abnormally fused together. The medical term "synostosis" means the joining or fusion of two or more bones that are normally separate. This fusion can happen before birth during development or progress during childhood. It can affect fingers, toes, forearm bones, or other limb bones, and may limit movement and function of the affected joints. Because this is an obsolete umbrella category rather than a single specific disease, the conditions that were once grouped here have since been reclassified into more specific diagnoses. Examples include conditions like multiple synostoses syndrome, proximal symphalangism, tarsal-carpal coalition syndrome, and other skeletal dysplasias involving bone fusion. Each of these specific conditions has its own genetic cause, inheritance pattern, and clinical features. If you or your child has been given a diagnosis that falls under this older category, it is important to work with a clinical geneticist to identify the specific underlying condition. A precise diagnosis will help guide treatment, genetic counseling, and long-term management. Treatment for bone fusion syndromes is generally supportive and may include surgery to improve joint movement, physical therapy, and pain management. There are currently no cures for these genetic skeletal conditions, but care can significantly improve quality of life.
Key symptoms:
Fusion of bones in the hands or feetStiff or immovable jointsLimited range of motion in arms or legsFused fingers or toesShort fingers or toesDifficulty gripping or grasping objectsPain in affected jointsAbnormal walking or gaitHearing loss in some subtypesForearm bones fused togetherDifficulty with fine motor tasksSkeletal deformities visible on X-ray
Variable
Can be inherited in different ways depending on the underlying gene
Neonatal
Begins at or shortly after birth (first 4 weeks)
FDA & Trial Timeline
2 eventsSohag University — NA
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for OBSOLETE: Syndromes with synostoses of limbs.
1 clinical trialare actively recruiting — trials can provide access to cutting-edge therapies.
View clinical trials →Specialists
View all specialists →No specialists are currently listed for OBSOLETE: Syndromes with synostoses of limbs.
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 OBSOLETE: Syndromes with synostoses of limbs.
Community
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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 is the specific syndrome causing the bone fusions in my child or me?,Which gene is responsible, and what does genetic testing show?,Will the bone fusions get worse over time?,Would surgery help improve joint movement, and what are the risks?,What therapies can help maintain function in daily activities?,Is there a risk of passing this condition to future children?,Are there any other organs or systems I should be monitored for?
Common questions about OBSOLETE: Syndromes with synostoses of limbs
What is OBSOLETE: Syndromes with synostoses of limbs?
"Syndromes with synostoses of limbs" is an obsolete (no longer actively used) grouping term from the Orphanet rare disease classification system. It was used to describe a collection of rare genetic conditions in which bones in the arms, legs, hands, or feet become abnormally fused together. The medical term "synostosis" means the joining or fusion of two or more bones that are normally separate. This fusion can happen before birth during development or progress during childhood. It can affect fingers, toes, forearm bones, or other limb bones, and may limit movement and function of the affecte
At what age does OBSOLETE: Syndromes with synostoses of limbs typically begin?
Typical onset of OBSOLETE: Syndromes with synostoses of limbs is neonatal. Age of onset can vary across affected individuals.
Are there clinical trials for OBSOLETE: Syndromes with synostoses of limbs?
Yes — 1 recruiting clinical trial is currently listed for OBSOLETE: Syndromes with synostoses of limbs on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.