The cover of 'Rare Disease Series #18 Long QT syndrome'


Diagram showing two different types of Long QT syndrome: Congenital and Acquired

Long QT syndrome is a rare genetic heart disorder that can cause fast heartbeats, sometimes leading to fainting or seizure. Many people with long QT syndrome don’t experience any signs or symptoms, but it could even cause sudden death in some severe cases.

Long QT syndrome can be grouped into two groups: congenital and acquired

Congenital long QT syndrome is more common. So far, more than 17 genes have been found to cause it. Romano-Ward syndrome and Jervell and Lange-Nielsen syndrome are the two well-known forms of this group.

Certain medical conditions or medications can cause acquired long QT syndrome. The symptoms usually disappear when the cause is removed.


Map background with silhouettes of different stages from baby to adult and words saying "Long QT syndrome is known to afect approximately 1 in 2,000 to 2,500 globally."
Long QT syndrome is known to affect approximately 1 in 2,000 to 2,500 globally.

The symptoms can appear at any age, but the first episode usually occurs before age 40.


Three symptoms of LONG QT SYNDROME: fainting, seizures, heart palpitations


As mentioned above, some people may experience the symptoms listed, but most people do not experience such signs or symptoms.

Many times, people with Long QT syndrome realize they have the condition by below reasons. These also could lead to the diagnosis.

  • Electrocardiogram(ECG) result
  • Family history of long QT syndrome
  • Genetic testing result


Two family trees showing autosomal dominant pattern and autosomal recessive inheritance pattern of Long QT syndrome
Congenital long QT syndromes are inherited as dominant or recessive patterns.

Romano-Ward syndrome has been found to inherit in an autosomal dominant pattern.
On the other hand, Jervell and Lange-Nielsen syndrome is known to inherit in an autosomal recessive pattern.


  1. ic-treatments-black@3x-3
  2. For most people with congenital long QT syndrome, beta-blockers can be used to treat irregular heartbeats. However, if the symptoms are severe, implementing a pacemaker or implantable cardioverter-defibrillator(ICD) could help.
    If the long QT syndrome is an acquired form, regular health checkups and reviewing current medications, and replacing them with others could be enough to treat or prevent it.

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