Now it is not possible to determine which ground can predispose a person more than another with genetic transfers supporting the Long QT Syndrome.

In these ten last years, spectacular progress was made in the field of molecular biology.

In 1991, the geneticist Mark KEATING and his colleagues of the University Hospital of Utah with the U.S.A, discovered 1st gene responsible for LQTS ; thereafter and rather quickly of other genes will be identified.

The Long QT Syndrome can be caused by transfers of different genes.A sixth gene has just discovered. For LQT1 (gene KVLQT1) more of 100 transfers genetic have been discovered.

Obviously of other genes will be discovered in the years to come because certain people reached of SQTL are not not listed in various known genes. The genetic transfers play a significant role in the gravity of the disease, they produce different symptoms from where strong probability that two people carrying same gene are with a degree very different from the disease, this being with the modification of these genes. Each person being tributary of a quite specific inheritance genetic. The genes produce an anomaly in the cardiac channels, they are partly responsible for the disorder of the electric system of the causing heart of the additional beats which modify the blood circulation to the brain as well as with other vital bodies, these arrhythmias are as many predispositions at the risk of sudden death by ventricular fibrillation.

· LQT1 - Gene KVLQT1, on Chromosome 11 is at the origin of anomalies of the potassic channel.

· LQT2 - Gene HERG, on Chromosome 7 is also at the origin of anomalies of the potassic channel.

· LQT3 - Gene SCNA, on chromosome 3 is at the origin of anomalies of the sodic channel.

· LQT4 - Locus LQT4 on chromosome 4q.25-27 ( gene unknown).

· LQT5 - Gene KCNE1 on chromosome 21 is at the origin of anomalies of the potassic channel .

· LQT6 - Gene KCNE2, on chromosome 21 is at the origin of anomalies of the potassic channel.

· LQT7 - Gene KCNJ2, on chromosome  17 is at the origin of anomalies of the potassic channel..
QT 7 is associated to the anderson Syndrome, for more information of this syndrome.

http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=FR&Expert=37553

· QT8 - Gene CACNA1C (Cav1.2), on chromosome  12p13.3 associated to the Timoty syndrome.

· QT9 - Gene CAV3 , on chromosome  3 possibility of disease of the muscle .

· QT10 -Gene SCN4B ,on chromosome  11 observed in only one family .




Traditional circumstances of occurred of the syncopes(traditional but non systematic)

· QT 1 rather with the effort

· QT 2 rather with the stress (ringing of telephone, strong emotion)

· QT 3 rather at rest (during the sleep, while reading….)


-Last update-september 3 2008-

Copyright2008 -Long QT syndrome association-