Timothy Syndrome

Identified as a syndrome in 2004

Webbed or fused fingers and toes (syndactyly)
Webbed or fused fingers and toes (syndactyly). Photo © A.D.A.M.

In 1989, a child came to the office of Dr. Katherine W. Timothy of the University of Utah. Dr. Timothy noted that the child had a heart rhythm disturbance and webbed fingers and toes. This child had what came to be known as Timothy syndrome, named in honor of Dr. Timothy's distinguished career as a scientist investigating the causes of irregular heart rhythms.

In 2004, an international team of researchers pinpointed the genetic mutation responsible for Timothy syndrome in a gene called CACNA1C, and formally identified the syndrome in the medical literature.

The mutation which causes the syndrome occurs spontaneously and is not inherited.

It is not known how many children are affected by Timothy syndrome. The researchers identified 17 children, and believe other children with the syndrome will be diagnosed as the medical community learns about the disorder.


Children with Timothy syndrome have a problem with the flow of calcium in the body cells. Calcium is one of the most important molecules in the body, and disturbing its flow can cause a wide range of symptoms. These may include:

  • Potentially fatal heart rhythm disturbances
  • Heart defects
  • Webbed fingers and toes (syndactyly)
  • Weakened immune system
  • Cognitive difficulties
  • Autism
  • Low blood sugar (hypoglycemia)


Any child born with webbed fingers or toes is checked to see if he or she has a genetic disorder. An electrocardiogram (ECG) will detect any abnormal heart rhythms. An echocardiogram (ultrasound of the heart) will detect any heart defects.

Autism is a complex disorder and may be difficult to detect. The combination of webbed fingers and toes and abnormal heart rhythm will suggest a diagnosis of Timothy syndrome.


The good news is that the abnormal flow of calcium in the body can be treated with calcium-channel blocking medications such as Calan (verapamil) or Procardia (nifedipine).

The researchers are treating the children with Timothy syndrome with this type of medication, hoping that the drugs will reduce the irregular heart rhythms and improve cognitive function.

Research continues

The team of researchers is continuing their work, evaluating how calcium-channel blocking medications affect individuals with Timothy syndrome. They will also continue to look for genes which cause irregular heart rhythms, and how abnormal calcium flow in the body may be related to autism.


"Rare Childhood Genetic Syndrome Identified." News Releases. 30 Sept 2004. Children's Hospital Boston. Jan 2005.

"Timothy Syndrome." Index of Rare Diseases. 04 Apr 2007. National Organization for Rare Disorders. 23 Jun 2007.

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