Mr Michał Tendera
The ESC Rene Laennec Lecture on Clinical Cardiology is one of the four Named Lectures, awarded by the ESC to leading clinicians and researchers in the field of basic, clinical and population sciences, as well as interventional cardiology.
The Rene Laennec Lecture 2007 was awarded by the ESC Board to Prof. William J. McKenna, Professor of Cardiology at the University College London, Director of Cardiology In The Young and Clinical Director of Cardiovascular Services at the Heart Hospital (UCLH NHSTrust), and Honorary Consultant in Cardiology at the Hospital for Sick Children, Great Ormond Street, London. His main interests have been in clinical and basic research of the cardiomyopathies. His recent work has contributed to the identification of disease-causing genes in hypertrophic, dilated and arrhythmogenic right ventricular cardiomyopathy, to the establishment of new diagnostic criteria within the context of familial disease, and to the establishment of algorithms to identify patients at high risk of sudden death.
As a topic for his lecture, Prof. McKenna chose “The role of genetic testing in hypertrophic cardiomyopathy”. He pointed out to the fact that hypertrophic cardiomyopathy (HCM) can be caused by mutations in genes encoding for different components of the sarcomere. Between 15 and 30% of all cases are caused by mutations in beta-myosin heavy chain, and a similar proportion in those relative to myosin binding protein C. Less common mutations are related to troponin I and T, regulatory myosin light chain, alpha-tropomyosin, actin, essential myosin light chain, titin, troponin C, alpha-myosin and LIM. These mutations have different penetration and phenotypic expression, and are associated with different risk profiles.
On the other hand, some well defined genetic conditions, such as Forbe’s and Pompe’s diseases, Noonan’s and LEOPARD syndromes, or Friedereich’s ataxia, can be associated by phenotypic left ventricular hypertrophy that can mimic HCM. Potential clinical value of genetic testing is related to both diagnosis and management of patients with HCM. It enables identification of asymptomatic disease carriers and those with incomplete expression, and facilitates prognostic assessment and genetic councelling.
Beta-myosin heavy chain mutations are characterized by expression of the disease in adolescence, and by allelic heterogeneity in relation to morphology, symptoms and prognosis. In patients with troponin I mutations, disease penetrance is in the order of 50%, and there are marked differences in expression and prognosis. Sudden death is associated with more severe hypertrophy. In contrast, patients with troponin T mutations experience disease expression in adolescence, the symptoms are mild, and left ventricular hypertrophy tends to be mild or absent, but the risk of premature sudden death is high.
Myosin binding protein C mutations produce a late onset disease, in which arrhythmias, embolic episodes and sudden death are associated with disease expression.
Different approaches are possible to perform genetic testing in patients with known or suspected HCM, including direct sequencing of all disease causing genes, and more focused techniques, like chip technology for known mutations. Due to genetic testing the disease has been better understood. It is now known that its prevalence in population is 1:500, about 90% of cases are familial, many individuals affected do not have intraventricular septal thickness >15 mm, and most have no obstruction.
The role of genetic testing is likely to increase in the future, since it is driven by scientific advancement, need for improved understanding of natural history, demand for improved treatment, including presymptomatic interventions, and by medico-legal implications of inactivity in search of this potentially lethal disease.
At the end of the session Prof. McKenna received a diploma and the Silver Medal of the European Society of Cardiology.
ESC Rene Laennec Lecture on Clinical Cardiology
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