POLYMORPHISMS AT THE ANGIOTENSINOGEN (AGT) AND ANGIOTENSIN-II TYPE-1 RECEPTOR (AT1R) LOCI AND NORMAL BLOOD-PRESSURE

The M235T polymorphism at the angiotensinogen (AGT) locus and the A116 6C polymorphism at the angiotensin II type 1 receptor (AT1R) locus hav e been reported to be associated with hypertension in several populati ons. We examined these polymorphisms in three samples of healthy Norwe gians with respect to normal blood pressure (BP) levels. None of the g enotypes defined by the polymorphisms or their combinations were assoc iated with systolic (S) BP (SBP) or diastolic (D) BP (DBP) level. Howe ver. there was a trend in all three series that individuals carrying t he C allele of the A1166C polymorphism at the AT1R locus (homozygotes as well as heterozygotes) had higher SBP, than AA homozygous individua ls. The observation did not reach statistical significance in any of t he series. When examining these two polymorphisms with respect to poss ible variability gene effects on BP in two series of monozygote (MZ) t win pairs, no such effect was detected. We could not detect any intera ction between the loci studied with respect to BP level or variability . Thus, neither the AGT locus nor AT1R locus, separately analysed or t ogether, seem to have variability gene effects or definite level gene effects on normal BP.