title: Of founder populations, long QT syndrome, and destiny.
abstract: Founder populations, characterized by a single ancestor affected by long QT syndrome (LQTS) and by a large number of individuals and families who all are related to the ancestor and thereby carry the same disease-causing mutation, represent the ideal human model for studying the role of "modifier genes" in LQTS. This article reviews some of the fundamental concepts related to founder populations and provides the necessary historical background to understand why so many can be found in South Africa. The focus then moves to a specific LQT1 founder population, carrier of the A341V mutation, that has been studied extensively during the last 10 years and has provided a significant amount of previously unforeseen information. These novel findings range from an unusually high clinical severity not explained by the electrophysiologic characteristics of the mutation, to the importance of tonic and reflex control of heart rate for risk stratification, to the identification of the first modifier genes for clinical severity of LQTS.
authors.affiliation: Department of Internal Medicine, University of Stellenbosch, South Africa.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Brink
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Schwartz
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics; D000328:Adult; D017704:Baroreflex; D002648:Child; D016757:Death, Sudden, Cardiac / Q000209:etiology; D018572:Disease-Free Survival; D005260:Female; D018703:Founder Effect; D020022:Genetic Predisposition to Disease; D005828:Genetics, Population; D006579:Heterozygote; D006801:Humans; D051657:KCNQ1 Potassium Channel / Q000235:genetics; D008133:Long QT Syndrome / Q000150:complications / Q000235:genetics* / Q000401:mortality / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010375:Pedigree; D011110:Polymorphism, Genetic; D000067759:Receptor for Advanced Glycation End Products; D011941:Receptors, Adrenergic / Q000235:genetics; D011971:Receptors, Immunologic; D013019:South Africa; D016019:Survival Analysis; D044465:White People / Q000235:genetics
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051657:KCNQ1 Potassium Channel; C488081:NOS1AP protein, human; D000067759:Receptor for Advanced Glycation End Products; D011941:Receptors, Adrenergic; D011971:Receptors, Immunologic