Timothy syndrome

Other Names: 

LQT8; Long QT syndrome type 8; Long QT syndrome-syndactyly syndrome

Summary

Timothy syndrome is a disorder that affects the heart, digits (toes and fingers), and nervous system (brain and nerves). It is a type of long QT syndrome. Long QT syndrome refers to a prolonged QT interval measurement seen on the electrocardiogram. Symptoms of Timothy syndrome include fusion of the skin between fingers or toes (syndactyly), distinctive facial features, and congenital heart defects. Additional symptoms may include developmental delay, intellectual disability, and autism spectrum disorders. There are two forms of Timothy syndrome, classified based on signs and symptoms. Type 1, known as classic type, includes all of the symptoms described above. Type 2, or atypical type, causes a more severe form of long QT syndrome and does not appear to include syndactyly. Both types are caused by genetic changes in the CACNA1C gene and are inherited in an autosomal dominant manner.

About Timothy syndrome

Many rare diseases have limited information. Currently, GARD aims to provide the following information for this disease:

• Population Estimate:Fewer than 1,000 people in the U.S. have thisdisease.
• Symptoms:May start to appear during Pregnancy and as a Newborn.
• Cause:This disease is caused by a change in the genetic material (DNA).
• Organizations:Patient organizations are available to help find a specialist, or advocacy and support for this specific disease.
• Categories:Genetic DiseasesNeurological Diseases

Genetic Mutations

Timothy syndrome is caused by genetic mutations, also known as pathogenic variants. Genetic mutations can be hereditary, when parents pass them down to their children, or they may occur randomly when cells are dividing. Genetic mutations may also result from contracted viruses, environmental factors, such as UV radiation from sunlight exposure, or a combination of any of these. Learn more about genetic diseases from the National Library of Medicine (NLM).

If you suspect you may have this disease, you may want to start collecting your family health history. Information such as other family members who have had similar symptoms, when their/your symptoms first appeared, or exposures to any potential disease-causing environmental factors should be discussed with your medical team. This tool from the Surgeon General can help you collect your family health history.

Autosomal Dominant

Autosomal means the gene involved is located on one of the numbered chromosomes. Dominant means that a child only needs to inherit one copy of the mutated gene, from either biological parent, to be affected by the disease.

People affected by an autosomal dominant disease have a 50% chance of passing on the mutated gene to their biological child.

Learn more about inheritance patterns from the National Library of Medicine (NLM).

When Do Symptoms of Timothy syndrome Begin?

Symptoms of this disease may start to appear during Pregnancy and as a Newborn.

The age symptoms may begin to appear differs between diseases. Symptoms may begin in a single age range, or during several age ranges. The symptoms of some diseases may begin at any age. Knowing when symptoms may have appeared can help medical providers find the correct diagnosis.