[Molecular genetics methods in the study of hereditary essential hypertension]

The main task in hypertension research is to explain genetic causes of a raised blood pressure. It is anticipated that advances in this area will promote not only a better understanding of the pathophysiology of hypertension but will make a more aimed approach to early diagnosis, prevention and therapy of essential hypertension possible. The greatest problems in investigations of the heredity of hypertension are; a) in cardiovascular control mechanisms several genes participate; b) factors of the external environment which act on a long-term basis interfere with the relationship of the genotype and phenotype individually, within the family and regionally; c) the blood pressure is a continuous variable and the definition of the phenotype of hypertension is inaccurate; d) inadequate number of family members where hypertension segregates. New methods in molecular biology and statistical genetics made it possible to assess a number of highly polymorphous genetic signs in several candidate genes and the subsequent investigation of their possible role in the pathogenesis of hypertension. The majority of hitherto accomplished studies was concentrated on genes coding different components of the renin-angiotensin system: renin, ACE, angiotensinogen and angiotensin II receptors. So far the most promising, though not consistent, results were obtained for angiotensinogen and the insulin receptor. Work focused on the relationship of the polymorphism of genes for ANF, growth hormone and kallikrein to essential hypertension is negative. The genetic heterogeneity of the human population, physiological differences in the genesis of high blood pressure in different ethnical groups and inaccurate measurements of specific phenotypes can contribute to different results of different studies.