Overview
Ulnar hemimelia, also known as ulnar longitudinal deficiency or ulnar club hand, is a rare congenital condition where the ulna bone (the bone on the pinky-finger side of the forearm) is partially or completely missing on one arm. This condition is present at birth and occurs during early fetal development when the limb is forming. The term 'unilateral' means it affects only one arm. Note that this specific Orphanet entry (295075) is marked as 'OBSOLETE,' meaning it has been retired or merged into a broader classification, but the underlying condition still exists under updated terminology. When the ulna is absent or underdeveloped, the forearm may appear shorter or curved, and the hand and fingers on the affected side may also be abnormal. Children may have missing or fused fingers, a curved or bowed radius bone, and limited movement at the wrist or elbow. The severity varies widely — some children have only mild shortening while others have significant limb differences. Treatment depends on how much the condition affects hand and arm function. Options may include physical therapy, occupational therapy, splinting, and in some cases surgery to straighten the forearm, improve hand function, or stabilize the elbow or wrist. Prosthetic devices may also be helpful. Many children adapt remarkably well and lead active, fulfilling lives. Early evaluation by a team of specialists is important to plan the best approach for each child.
Also known as:
Key symptoms:
Missing or shortened ulna bone in one forearmCurved or bowed forearmShorter arm on the affected sideMissing or fused fingers on the affected handLimited elbow movement or unstable elbow jointLimited wrist movementAbnormal hand positioning or wrist deviationReduced grip strength on the affected sideUnequal arm length compared to the other sidePossible abnormalities of the thumb or first finger
Variable
Can be inherited in different ways depending on the underlying gene
Neonatal
Begins at or shortly after birth (first 4 weeks)
Treatments
No FDA-approved treatments are currently listed for OBSOLETE: Ulnar hemimelia, unilateral.
View clinical trials →Clinical Trials
View all trials with filters →No actively recruiting trials found for OBSOLETE: Ulnar hemimelia, unilateral at this time.
New trials open frequently. Follow this disease to get notified.
Specialists
View all specialists →No specialists are currently listed for OBSOLETE: Ulnar hemimelia, unilateral.
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: Ulnar hemimelia, unilateral.
Community
No community posts yet. Be the first to share your experience with OBSOLETE: Ulnar hemimelia, unilateral.
Start the conversation →Latest news about OBSOLETE: Ulnar hemimelia, unilateral
No recent news articles for OBSOLETE: Ulnar hemimelia, unilateral.
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.How severe is my child's ulnar deficiency, and what bones and joints are affected?,Is this an isolated condition or could it be part of a genetic syndrome?,Should we pursue genetic testing to look for an underlying cause?,What are the surgical options, and when is the best time for surgery?,How can occupational therapy help my child's hand function?,Will my child need a prosthetic device, and if so, when should we start?,What should we watch for as my child grows that might require additional treatment?
Common questions about OBSOLETE: Ulnar hemimelia, unilateral
What is OBSOLETE: Ulnar hemimelia, unilateral?
Ulnar hemimelia, also known as ulnar longitudinal deficiency or ulnar club hand, is a rare congenital condition where the ulna bone (the bone on the pinky-finger side of the forearm) is partially or completely missing on one arm. This condition is present at birth and occurs during early fetal development when the limb is forming. The term 'unilateral' means it affects only one arm. Note that this specific Orphanet entry (295075) is marked as 'OBSOLETE,' meaning it has been retired or merged into a broader classification, but the underlying condition still exists under updated terminology. Wh
At what age does OBSOLETE: Ulnar hemimelia, unilateral typically begin?
Typical onset of OBSOLETE: Ulnar hemimelia, unilateral is neonatal. Age of onset can vary across affected individuals.