The blood pressure genes include ATP2B1 which encodes PMCA1, a cell membrane enzyme that is involved in calcium transport; CACNB2, which encodes part of a calcium channel protein; and CYP17A1 which encodes an enzyme that is necessary for steroid production. One detected variant is within the gene SH2B3 and has been associated with autoimmune diseases, hinting that pathways involved with the immune response may influence blood pressure.

Blood pressure is measured in millimeters of mercury (mm Hg), and expressed with two numbers, for example, 120/80 mm Hg. The first number (systolic pressure) is the pressure when the heart beats while pumping blood. The second number (diastolic pressure) is the pressure in large arteries when the heart is at rest between beats.

Researchers found that the top 10 gene variants, or SNPs, for systolic and diastolic blood pressure were each associated with around a 1 and 0.5 mm Hg increase in systolic and diastolic blood pressure, respectively. The prevalence of hypertension increased as the number of variants increased.

People who carry very few blood pressure genetic risk variants have blood pressure levels that are several mm Hg lower than those who carry multiple risk variants. In practical terms this is enough to increase the risk for cardiovascular disease. A prolonged increase in DBP of only 5 mm Hg is associated with a 34 percent increase in risk for stroke and a 21 percent increase of coronary heart disease.

The research was funded by NHLBI grants and contracts and was also supported by the National Human Genome Research Institute (NHGRI), National Center for Research Resources (NCRR), National Institute on Aging (NIA), and the NIH Roadmap.

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