What other heart conditions is Wolff-Parkinson-White syndrome associated with?
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.
Palpitations are unpleasant sensations of irregular and/or forceful beating of the heart. Palpitations can be relieved in many patients by stress reduction, stopping cigarettes, and reduction of caffeine and alcohol.
Heart rhythm disorders vary from minor palpitations, premature atrial contractions (PACs), premature ventricular contractions (PVCs), sinus tachycardia, and sinus brachycardia, to abnormal heart rhythms such as tachycardia, ventricular fibrillation, ventricular flutter, atrial fibrillation, atrial flutter, paroxysmal supraventricular tachycardia (PSVT), Wolf-White-Parkinson syndrome, brachycardia, or heart blocks. Treatment is dependant upon the type of heart rhythm disorder.
Sudden cardiac arrest is an unexpected, sudden death caused by sudden cardiac arrest (loss of heart function). Causes and risk factors of sudden cardiac arrest include (not inclusive): abnormal heart rhythms (arrhythmias), previous heart attack, coronary artery disease, smoking, high cholesterol, Wolff-Parkinson-White Syndrome, ventricular tachycardia or ventricular fibrillation after a heart attack, congenital heart defects, history of fainting, and heart failure, obesity, diabetes, and drug abuse. Treatment of sudden cardiac arrest is an emergency, and action must be taken immediately.
Genetic disease is a disorder or condition caused by abnormalities in a person's genome. Types of genetic inheritance include single inheritance (for example, cystic fibrosis, sickle cell anemia, Marfan syndrome, and hemochromatosis), multifactoral inheritance, chromosome abnormalities (for example, Turner syndrome, and Klinefelter syndrome), and mitochondrial inheritance (for example, epilepsy and dementia).
Paroxysmal supraventricular tachycardia (PSVT) is an abnormal conduction of electricity in particular areas of the heart. PSVT was referred to at one time as paroxysmal atrial tachycardia or PAT, however, the term PAT is reserved for as specific heart condition. Symptoms of PSVT include weakness, shortness of breath, chest pressure, lightheadedness, and palpitations. PSVT is treated with medications or procedures that return the heart to its normal electrical pattern.
Your health care provider may refer you to a genetic professional. Universities and medical centers also often have affiliated genetic professionals, or can provide referrals to a genetic professional or genetics clinic. Genetic counseling provides patients and family members the tools to make the right choice in regard to test for a disease or condition.