ObjectivesTo compare the distributions of the genotypes and alleles of the M235T polymorphism of the angiotensinogen gene for hypertensive patients and normotensive controls.DesignA study of association of genetic polymorphisms.SettingAn outpatient clinic run by a university department handling referrals from primary care.PatientsTwo hundred and four subjects, 103 normal controls and 101 patients with newly diagnosed or documented hypertension.MethodGenomic DNA was extracted from peripheral blood leucocytes, amplified by polymerase chain reaction and digested with the restriction enzyme Tth 111 I. Methionine (M) and threonine (T) alleles were identified after electrophoresis.Main outcome measuresPrevalences of angiotensinogen genotypes and alleles for hypertensive patients and controls.ResultsMM, TM and TT genotypes occurred in 3, 24 and 73% of controls and 1, 22 and 77% of hypertensive patients, respectively. The prevalences of the M and T alleles were 0.15 and 0.85 among controls and 0.12 and 0.88 among hypertensive patients. The prevalences of the angiotensinogen genotypes and alleles for controls and hypertensive patients did not differ significantly.ConclusionsOur findings differed from previous reports and suggested that this polymorphism is not associated with hypertension in this population.