Wolff-Parkinson-White Syndrome

Wolff-Parkinson-White syndrome is a condition characterized by abnormal electrical pathways in the heart that cause a disruption of the heart's normal rhythm (arrhythmia).

The heartbeat is controlled by electrical signals that move through the heart in a highly coordinated way. A specialized cluster of cells called the atrioventricular node conducts electrical impulses from the heart's upper chambers (the atria) to the lower chambers (the ventricles). Impulses move through the atrioventricular node during each heartbeat, stimulating the ventricles to contract slightly later than the atria.

What is Wolff-Parkinson-White Syndrome?
People with Wolff-Parkinson-White syndrome are born with an extra connection in the heart, called an accessory pathway, that allows electrical signals to bypass the atrioventricular node and move from the atria to the ventricles faster than usual. The accessory pathway may also transmit electrical impulses abnormally from the ventricles back to the atria. This extra connection can disrupt the coordinated movement of electrical signals through the heart, leading to an abnormally fast heartbeat (tachycardia) and other arrhythmias. Resulting symptoms include dizziness, a sensation of fluttering or pounding in the chest (palpitations), shortness of breath, and fainting (syncope). In rare cases, arrhythmias associated with Wolff-Parkinson-White syndrome can lead to cardiac arrest and sudden death. The most common arrhythmia associated with Wolff-Parkinson-White syndrome is called paroxysmal supraventricular tachycardia.

Complications of Wolff-Parkinson-White syndrome can occur at any age, although some individuals born with an accessory pathway in the heart never experience any health problems associated with the condition.

Wolff-Parkinson-White syndrome often occurs with other structural abnormalities of the heart or underlying heart disease. The most common heart defect associated with the condition is Ebstein anomaly, which affects the valve that allows blood to flow from the right atrium to the right ventricle (the tricuspid valve). Additionally, Wolff-Parkinson-White syndrome can be a component of several other genetic syndromes, including hypokalemic periodic paralysis (a condition that causes episodes of extreme muscle weakness), Pompe disease (a disorder characterized by the storage of excess glycogen), and tuberous sclerosis (a condition that results in the growth of noncancerous tumors in many parts of the body).

How common is Wolff-Parkinson-White syndrome?
Wolff-Parkinson-White syndrome affects 1 to 3 in 1,000 people worldwide. Only a small fraction of these cases appear to run in families.

Wolff-Parkinson-White syndrome is a common cause of an arrhythmia known as paroxysmal supraventricular tachycardia. Wolff-Parkinson-White syndrome is the most frequent cause of this abnormal heart rhythm in the Chinese population, where it is responsible for more than 70 percent of cases.

What genes are related to Wolff-Parkinson-White syndrome?
Mutations in the PRKAG2 gene cause Wolff-Parkinson-White syndrome.

A small percentage of all cases of Wolff-Parkinson-White syndrome are caused by mutations in the PRKAG2 gene. Some people with these mutations also have features of hypertrophic cardiomyopathy, a form of heart disease that enlarges and weakens the heart (cardiac) muscle. The PRKAG2 gene provides instructions for making a protein that is part of an enzyme called AMP-activated protein kinase (AMPK). This enzyme helps sense and respond to energy demands within cells. It is likely involved in the development of the heart before birth, although its role in this process is unknown.

Researchers are uncertain how PRKAG2 mutations lead to the development of Wolff-Parkinson-White syndrome and related heart abnormalities. Research suggests that these mutations alter the activity of AMP-activated protein kinase in the heart, although it is unclear whether the genetic changes overactivate the enzyme or reduce its activity. Studies indicate that changes in AMP-activated protein kinase activity allow a complex sugar called glycogen to build up abnormally within cardiac muscle cells. Other studies have found that altered AMP-activated protein kinase activity is related to changes in the regulation of certain ion channels in the heart. These channels, which transport positively charged atoms (ions) into and out of cardiac muscle cells, play critical roles in maintaining the heart's normal rhythm.

In most cases, the cause of Wolff-Parkinson-White syndrome is unknown.

Read more about the PRKAG2 gene.

How do people inherit Wolff-Parkinson-White syndrome?
Most cases of Wolff-Parkinson-White syndrome occur in people with no apparent family history of the condition. These cases are described as sporadic and are not inherited.

Familial Wolff-Parkinson-White syndrome accounts for only a small percentage of all cases of this condition. The familial form of the disorder typically has an autosomal dominant pattern of inheritance, which means one copy of the altered gene in each cell is sufficient to cause the condition. In most cases, a person with familial Wolff-Parkinson-White syndrome has inherited the condition from an affected parent.

What other names do people use for Wolff-Parkinson-White syndrome?

 * Ventricular pre-excitation with arrhythmia
 * WPW Syndrome

Where can I find information about treatment for Wolff-Parkinson-White syndrome?
These resources address the management of Wolff-Parkinson-White syndrome and may include treatment providers.


 * Genetic Alliance[[Image:offsiteico.gif|This link leads to a site outside Genetics Home Reference.]]
 * MedlinePlus Encyclopedia: Wolff-Parkinson-White syndrome[[Image:offsiteico.gif|This link leads to a site outside Genetics Home Reference.]]

You might also find information on treatment of Wolff-Parkinson-White syndrome in Educational resources and Patient support.

Where can I find additional information about Wolff-Parkinson-White syndrome?
You may find the following resources about Wolff-Parkinson-White syndrome helpful. These materials are written for the general public.


 * MedlinePlus - Health information (3 links)
 * Educational resources - Information pages (9 links)
 * Patient support - For patients and families (5 links)

You may also be interested in these resources, which are designed for healthcare professionals and researchers.


 * Gene Tests[[Image:offsiteico.gif|This link leads to a site outside Genetics Home Reference.]] - DNA tests ordered by healthcare professionals
 * ClinicalTrials.gov[[Image:offsiteico.gif|This link leads to a site outside Genetics Home Reference.]] - Linking patients to medical research
 * PubMed[[Image:offsiteico.gif|This link leads to a site outside Genetics Home Reference.]] - Recent literature
 * OMIM - Genetic disorder catalog (2 links)

See How are genetic conditions and genes named? in the Handbook.

What if I still have specific questions about Wolff-Parkinson-White syndrome?

 * See How can I find a genetics professional in my area? in the Handbook.
 * Ask the Genetic and Rare Diseases Information Center[[Image:offsiteico.gif|This link leads to a site outside Genetics Home Reference.]].
 * Submit your question to Ask the Geneticist[[Image:offsiteico.gif|This link leads to a site outside Genetics Home Reference.]].

Where can I find general information about genetic conditions?
The Handbook provides basic information about genetics in clear language.


 * What does it mean if a disorder seems to run in my family?
 * What are the different ways in which a genetic condition can be inherited?
 * If a genetic disorder runs in my family, what are the chances that my children will have the condition?
 * Why are some genetic conditions more common in particular ethnic groups?

These links provide additional genetics resources that may be useful.


 * Genetics and health
 * Resources for Patients and Families
 * Resources for Health Professionals

What glossary definitions help with understanding Wolff-Parkinson-White syndrome?
arrhythmia ; atom ; atrial ; atrial fibrillation ; atrioventricular node ; atrium ; autosomal ; autosomal dominant ; AV node ; cardiac ; cardiac arrest ; cardiomyopathy ; cell ; channel ; complication ; Ebstein anomaly ; enzyme ; fainting ; familial ; family history ; fibrillation ; gene ; glycogen ; hypertrophic ; inheritance ; ions ; kinase ; mutation ; palpitations ; pattern of inheritance ; population ; protein ; sclerosis ; sporadic ; supraventricular ; symptom ; syncope ; syndrome ; tachycardia ; tricuspid valve ; tumor ; ventricle

Related Videos
Dr. Joseph Pancrazio from the National Institute of Neurological Disorders and Stroke and Bill Schmalfeldt discuss deep brain stimulation as a treatment for Parkinson's disease (video donated by NIH):

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.