Is genotyping necessary to predict cardiovascular diseases?
Svetlana Gorokhova
MD, PhD, professor Research Clinical Center of JSC Russian Railways, Moscow, Russia
The potential of the introduction of genotyping in clinical practice is connected with personalized medicine, which involves the assessment of individual risk of diseases. Successes have been achieved in cardiology in respect of understanding the genetic predisposition to many cardiovascular diseases. Associations were established between cardiovascular risk factors (arterial hypertension, dyslipidemia, diabetes mellitus etc.) and genetic polymorphisms, as well as the dependence of the severity of clinical signs on the type of mutation (for example in case of long QT syndrome). However, the systems of cardiovascular risk stratification include only traditional clinical and laboratory signs (e.g. smoking, blood pressure, cholesterol level, body mass index). Genotyping is now considered a III Class diagnostic method (lack of
proven benefit in asymptomic patients) by international clinical
recommendations. In addition, there are no recommendations to perform genotyping to find predispositions to fatal heart rhythm disturbances. The only genetic tests considered justified are those to reveal mutations associated with life-threatening arrhythmias in persons with evident risk factors of arrhythmogenic channelopathy (family history of the disease, or positive stress tests), and in case of pathogenic mutations in the proband.
Along with this, scientists search for informative genetic markers of diseases, which are regularly complicated with significant clinical events such as myocardial infarction, stroke, fatal heart rhythm disturbances, and sudden death. Genetic laboratories propose programs of genetic testing for CVD.
In this respect, one should understand what genotyping can offer in the field of cardiovascular prediction, and how to formulate specific problems to solve by the introduction of genetic methods.
The report will consider these aspects, and our experience in the creation of prognostic models. We will discuss some problems of the research of cardiovascular genetic markers, genetic risk assessment, and issues the of clinical and economic advisability of genetic screening in the most important cardiovascular diseases.