U.S. flag

An official website of the United States government


Send to:

Choose Destination

Short QT syndrome type 1(SQT1)

MedGen UID:
Concept ID:
Disease or Syndrome
Synonym: Short QT Syndrome 1
Gene (location): KCNH2 (7q36.1)
Monarch Initiative: MONDO:0012312
OMIM®: 609620


Short QT syndrome (SQT) is a cardiac channelopathy associated with a predisposition to atrial fibrillation and sudden cardiac death. Patients have a structurally normal heart, but electrocardiography (ECG) exhibits abbreviated QTc (Bazett's corrected QT) intervals of less than 360 ms (summary by Moreno et al., 2015). Genetic Heterogeneity of Short QT Syndrome Short QT syndrome-2 (SQT2; 609621) is caused by mutation in the KCNQ1 gene (607542). SQT3 (609622) is caused by mutation in the KCNJ2 gene (600681). SQT7 (620231) is caused by mutation in the SLC4A3 gene (106195). [from OMIM]

Additional description

From MedlinePlus Genetics
If untreated, the arrhythmia associated with short QT syndrome can lead to a variety of signs and symptoms, from dizziness and fainting (syncope) to cardiac arrest and sudden death. These signs and symptoms can occur any time from early infancy to old age. This condition may explain some cases of sudden infant death syndrome (SIDS), which is a major cause of unexplained death in babies younger than 1 year. However, some people with short QT syndrome never experience any health problems associated with the condition.

Short QT syndrome is a condition that can cause a disruption of the heart's normal rhythm (arrhythmia). In people with this condition, the heart (cardiac) muscle takes less time than usual to recharge between beats. The term "short QT" refers to a specific pattern of heart activity that is detected with an electrocardiogram (EKG), which is a test used to measure the electrical activity of the heart. In people with this condition, the part of the heartbeat known as the QT interval is abnormally short.  https://medlineplus.gov/genetics/condition/short-qt-syndrome

Clinical features

From HPO
Sudden cardiac death
MedGen UID:
Concept ID:
Pathologic Function
The heart suddenly and unexpectedly stops beating resulting in death within a short time period (generally within 1 h of symptom onset).
Cardiac arrest
MedGen UID:
Concept ID:
An abrupt loss of heart function.
MedGen UID:
Concept ID:
A sensation that the heart is pounding or racing, which is a non-specific sign but may be a manifestation of arrhythmia.
MedGen UID:
Concept ID:
Sign or Symptom
Syncope is a syndrome in which loss of consciousness is of relatively sudden onset, temporary (usually less than 1 to 2 minutes), self-terminating, and of usually rapid recovery. Syncope leads to a generalized weakness of muscles with loss of postural tone, inability to stand upright, and loss of consciousness. Once the patient is in a horizontal position, blood flow to the brain is no longer hindered by gravitation and consciousness is regained. Unconsciousness usually lasts for seconds to minutes. Headache and drowsiness (which usually follow seizures) do not follow a syncopal attack. Syncope results from a sudden impairment of brain metabolism usually due to a reduction in cerebral blood flow.
Shortened QT interval
MedGen UID:
Concept ID:
Decreased time between the start of the Q wave and the end of the T wave as measured by the electrocardiogram (EKG).
Paroxysmal atrial fibrillation
MedGen UID:
Concept ID:
Disease or Syndrome
Episodes of atrial fibrillation that typically last for several hours up to one day and terminate spontaneously.

Professional guidelines


Stattin EL, Westin IM, Cederquist K, Jonasson J, Jonsson BA, Mörner S, Norberg A, Krantz P, Wisten A
Int J Legal Med 2016 Jan;130(1):59-66. Epub 2015 Jul 31 doi: 10.1007/s00414-015-1237-8. PMID: 26228265Free PMC Article
Schimpf R, Veltmann C, Papavassiliu T, Rudic B, Göksu T, Kuschyk J, Wolpert C, Antzelevitch C, Ebner A, Borggrefe M, Brandt C
Heart Rhythm 2012 May;9(5):776-81. Epub 2012 Jan 11 doi: 10.1016/j.hrthm.2012.01.006. PMID: 22245794Free PMC Article

Suggested Reading


Priori SG, Wilde AA, Horie M, Cho Y, Behr ER, Berul C, Blom N, Brugada J, Chiang CE, Huikuri H, Kannankeril P, Krahn A, Leenhardt A, Moss A, Schwartz PJ, Shimizu W, Tomaselli G, Tracy C; Document Reviewers, Ackerman M, Belhassen B, Estes NA 3rd, Fatkin D, Kalman J, Kaufman E, Kirchhof P, Schulze-Bahr E, Wolpert C, Vohra J, Refaat M, Etheridge SP, Campbell RM, Martin ET, Quek SC; Heart Rhythm Society; European Heart Rhythm Association; Asia Pacific Heart Rhythm Society
Europace 2013 Oct;15(10):1389-406. Epub 2013 Aug 30 doi: 10.1093/europace/eut272. PMID: 23994779

Recent clinical studies


Jæger KH, Wall S, Tveito A
PLoS Comput Biol 2021 Feb;17(2):e1008089. Epub 2021 Feb 16 doi: 10.1371/journal.pcbi.1008089. PMID: 33591962Free PMC Article


Jæger KH, Edwards AG, Giles WR, Tveito A
PLoS Comput Biol 2021 Aug;17(8):e1009233. Epub 2021 Aug 12 doi: 10.1371/journal.pcbi.1009233. PMID: 34383746Free PMC Article


Jæger KH, Wall S, Tveito A
PLoS Comput Biol 2021 Feb;17(2):e1008089. Epub 2021 Feb 16 doi: 10.1371/journal.pcbi.1008089. PMID: 33591962Free PMC Article

Clinical prediction guides

Jæger KH, Wall S, Tveito A
PLoS Comput Biol 2021 Feb;17(2):e1008089. Epub 2021 Feb 16 doi: 10.1371/journal.pcbi.1008089. PMID: 33591962Free PMC Article

Supplemental Content

Recent activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...