title: [QT syndrome: new diagnostic possibilities].
abstract: Electrocardiographic and clinical characteristics are currently used as diagnostic criteria for the long QT-syndrome. In borderline electrocardiographic findings associated with unclear syncope, it is often difficult to ensure or exclude long QT-syndrome. Schwartz and coworkers therefore created a point system as a guide in clinical decision making. In recent years genetic diagnostics have entered the arena of long-QT assessment. Aside from new insights into the pathophysiology of the long QT-disorder, it is expected that genetic diagnostics will offer substantial help to ascertain long QT-syndrome in patients with borderline electrocardiographic and clinical findings and improve risk stratification in long-QT family members. Performing linkage analysis, coupling of autosomal-dominant congenital long QT-syndrome (Romano-Ward Syndrome) to chromosomes 11 (LQT1/11p15.5), 3 (LQT3/3p21), 7 (LQT2/7q35), and 4 (LQT4/4q25-27) was demonstrated. More recently, the disease genes in long QT-syndrome 1, 2, and 3 could be identified. Analysis of the base-pair sequence allowed detection of several different mutations in different families illustrating genetic heterogeneity. Aside from diagnostic aspects, molecular genetics may also guide pharmacological therapy by identifying the specific ion-channel disorder leading to QT-prolongation and sudden death.
authors.affiliation: Medizinische Universitätsklinik und Poliklinik Bonn.
authors.forename: T
authors.initials: T
authors.lastname: Lewalter
authors.forename: S
authors.initials: S
authors.lastname: Englisch
authors.forename: S
authors.initials: S
authors.lastname: Jahr
authors.forename: B
authors.initials: B
authors.lastname: Schumacher
authors.forename: W
authors.initials: W
authors.lastname: Jung
authors.forename: R D
authors.initials: RD
authors.lastname: Hesch
authors.forename: B
authors.initials: B
authors.lastname: Lüderitz
mesh_terms: D002874:Chromosome Mapping; D016757:Death, Sudden, Cardiac / Q000517:prevention & control; D004562:Electrocardiography; D005799:Genes, Dominant / Q000235:genetics; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D008133:Long QT Syndrome / Q000175:diagnosis* / Q000235:genetics; D012307:Risk Factors