Renin-angiotensin-aldosterone system loci and multilocus interactions in young-onset essential hypertension

Objective: Renin-angiotensin-aldosterone system component genes have been associated to essential hypertension. Thus, we studied the association of singe locus or multilocus interactions with young-onset essential hypertension. Setting and Design: This is a case-control study based on a population sample of adolescent at an inner city. Participants: We studied 54 adolescents with hypertension and 121 age-matched normotensives, recruited from a high-school student population of 934 interviewed individuals. Methods: Resting blood pressure was measured on three different days and normalized (Z-score) by sex and age. Genotypes of ACE (I/D) angiotensinogen (T174M and M235T), AT1R (A1166C), and CYP11B2 (C-344T) were determined by PCR/RFLP or ASO. Results: Although genotype frequencies were not different in both groups, we found a significant dominant effect of ACE D and angiotensinogen 235T alleles on normalized systolic arterial blood pressure in males. This effect was confirmed by sib-pair linkage analysis taking normalized blood pressure.