Catalog

Long QT syndrome type 3

No MMS code

Link to WHO Definition

Long QT syndrome type 3 – http://id.who.int/icd/entity/1181962223

The LQT3 type of long QT syndrome involves mutation of the gene that encodes the alpha subunit of the Na+ ion channel. This gene is located on chromosome 3p21-24, and is known as SCN5A (also hH1 and NaV1.5). The mutations involved in LQT3 slow the inactivation of the Na+ channel, resulting in prolongation of the Na+ influx during depolarization. However, the mutant sodium channels inactivate more quickly, and may open repetitively during the action potential.