Overview
Timothy syndrome is a very rare genetic condition that affects the heart and several other parts of the body. It is sometimes called LQT8 (Long QT syndrome type 8) because one of its main features is a problem with the heart's electrical system called long QT syndrome. This means the heart takes longer than normal to recharge between beats, which can lead to dangerous irregular heartbeats (arrhythmias) and even sudden cardiac arrest. The condition is caused by a change (mutation) in a gene called CACNA1C, which controls a channel in heart and other cells that lets calcium flow in and out. When this channel does not work properly, it affects not just the heart but also the brain, immune system, fingers and toes, and facial features. Many children with Timothy syndrome also have autism spectrum disorder or other developmental delays, and some are born with webbed fingers or toes (a feature called syndactyly). There are two forms: Classic Timothy syndrome (Type 1) and a more severe form (Type 2). Symptoms often appear at birth or in early infancy. Treatment focuses on managing the heart rhythm problems using medications, implanted devices like pacemakers or defibrillators, and close monitoring. There is currently no cure, but careful heart management can help improve quality of life and reduce the risk of life-threatening events.
Key symptoms:
Dangerously irregular heartbeat (arrhythmia)Long QT interval on heart tracing (ECG)Webbed fingers or toes (syndactyly)Autism spectrum disorder or social communication difficultiesIntellectual disability or developmental delaysLow blood sugar (hypoglycemia)Weak immune system leading to frequent infectionsDistinctive facial features such as a flat nasal bridge and low-set earsSeizuresSudden fainting or loss of consciousnessHeart defects present at birth (congenital heart defects)Slow heart rate (bradycardia)
Sporadic
Usually appears on its own, not inherited from a parent
Neonatal
Begins at or shortly after birth (first 4 weeks)
FDA & Trial Timeline
1 eventHans-Peter Landolt — NA
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for Timothy syndrome.
View clinical trials →Clinical Trials
View all trials with filters →No actively recruiting trials found for Timothy syndrome at this time.
New trials open frequently. Follow this disease to get notified.
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 Timothy syndrome.
Community
No community posts yet. Be the first to share your experience with Timothy syndrome.
Start the conversation →Latest news about Timothy syndrome
Disease timeline:
New recruiting trial: A Causal Role for Voltage-gated Cav1.2 Calcium Channels in Mediating 5G FR1 Effects on Sleep-associated Brain Health in Humans
A new clinical trial is recruiting patients for Timothy syndrome
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.Does my child need an implantable defibrillator (ICD), and what are the risks and benefits?,Which medications are best for managing the heart rhythm, and what side effects should I watch for?,What physical activities are safe, and which ones should my child avoid?,Should other family members be tested for CACNA1C mutations?,What developmental or behavioral therapies do you recommend, and how do we access them?,What should I do if my child faints or has a seizure at home or at school?,Are there any clinical trials or research studies we should consider joining?
Common questions about Timothy syndrome
What is Timothy syndrome?
Timothy syndrome is a very rare genetic condition that affects the heart and several other parts of the body. It is sometimes called LQT8 (Long QT syndrome type 8) because one of its main features is a problem with the heart's electrical system called long QT syndrome. This means the heart takes longer than normal to recharge between beats, which can lead to dangerous irregular heartbeats (arrhythmias) and even sudden cardiac arrest. The condition is caused by a change (mutation) in a gene called CACNA1C, which controls a channel in heart and other cells that lets calcium flow in and out. Whe
How is Timothy syndrome inherited?
Timothy syndrome follows a sporadic inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Timothy syndrome typically begin?
Typical onset of Timothy syndrome is neonatal. Age of onset can vary across affected individuals.
Which specialists treat Timothy syndrome?
15 specialists and care centers treating Timothy syndrome are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.