The health significance of essential hypertension (high blood pressure of undefined origin) is well established. It is a major factor contributing to coronary heart disease, stroke, and kidney failure. It directly affects about one in five Americans. Factors which are known to be associated with blood pressure include: body composition as it relates to overall mass and fat mass; physiological variables involving the sympathetic and parasympathetic nervous systems; biochemical variables such as renin, aldosterone, kallikrein, lipids, and lipoproteins, etc.; environmental variables such as sodium intake, heavy metals, and noise; and psychological variables involving personality type and mental stress.There is a definite, well-established genetic involvement in hypertension, but specific genetic mechanisms remain a mystery. Familial aggregation occurs for many of the associated traits listed above. For some, specific polymorphic major genes have been identified, but for others genetic factors are unidentified. Essential hypertension is undoubtedly a heterogeneous group of diseases with the common end result of elevated blood pressure. Because of its health significance, there is considerable interest in identifying genetic mechanisms resulting in essential hypertension. One area that currently shows some potential for the identification of a specific genetic mechanism is related to the transmembrane transport of sodium and potassium cations.A genetic component has long been suspected in essential hypertension, but a clear and definitive genetic mechanism has yet to be identified. Since there are many variables that can affect blood pressure, this review of the genetics of essential hypertension necessarily involves a discussion of related traits. Before focusing on the genetic and familial aspects of hypertension a description of the normal course of human blood pressure is presented and some of the traits related to it are discussed.
NATURAL HISTORY OF BLOOD PRESSUREUntil recently, reports describing blood pressure patterns during the neonatal period were relatively few, largely because of the difficulty of accurately measuring blood pressure in infants by noninvasive techniques. The ultrasonic technique utilizing the Doppler effect greatly facilitated noninvasive systolic blood pressure determination in infants (McLaughlin et al., 1971). Accurate automatic methods are currently available using the oscillometric principal coupled with a microcomputer and a standard limb blood presure cuff (Friesen and Lichtor, 1981). Even in adults newer methods are being developed (Wolthuis et al., 1981).© 1983 Alan R. Liss, Inc. [Vol.26,1983 Systolic blood pressure tends to increase sharply during the first two weeks of life from a mean of 70 mmHg at 2 days to 84 mmHg at 2 weeks. It continues to increase at a slightly slower rate over the next 4 weeks to a mean of about 93 mmHg at 6 weeks (Earley et aI., 1980); from 6 weeks to 1 year af age there is little change in systolic pressure (deSwiet et aI., 1975(deSwiet et ...
