The long QT syndrome in South Africa

  • P.A. Brink Department of Medicine, University of Stellenbosch
  • V.A. Corfield US/MRC Centre for Molecular and Cellular Biology, University of Stellenbosch


The long QT syndromes (LQTS) are Mendelian inherited conditions where syncope and sudden death are due to precipitous occurrence of polymorphic ventricular tachycardia. In South Africa a number of white, some coloured and some Asian individuals have been identified but, interestingly, not a single black person and neither has it been reported from Africa. With over 400 known causal-mutations, mostly in cardiac ion channel-genes, it is unlikely to be absent in African populations. LQTS is notorious for going undiagnosed or misdiagnosed, perhaps even more so in Africa. Amongst persons of Afrikaner descent the KCNQ1 A341V-mutation represents a founder effect. The availability of 170 living individuals sharing the same mutation has made it possible to study factors modifying risk. A blunted autonomic response has been shown to decrease risk of attacks.