Study 1Association of G5 a Gene With Essential Hypertension inChineseObjective:We investigated whether the GNAS1 locus, encoding the Os protein a subunit(Gs a), is implicated in the genetic causes of essential hypertension (EH) in a Chinese population. Recently, a common silent polymorphism (A1TJ2 ATC, 11e131) was identified in exon 5 of the Os a gene. This polymorphism consists of the presence (+) or absence(-) of a restriction site for FokI. Methods: The polymorphism of Os ci gene was detected by polymerase chain reaction combined with restriction enzyme digestion in 142 hypertensive patients and 78 normotensive controls. Body mass index (BMD was also measured in all subjects. Serum total cholesterol (Tch), triglyceride (TG) , fasting serum glucose (Glu) and creatinine (Cr) were determined in 125 hypertensive patients. Parameters of left ventricular structure were assessed by echocardiographic method in 99 hypertensive patients. Results: There was significant difference in frequency of the Fold alleles between 142 hypertensive patients (FokJ+:Fold-; 41.5%:58.5%) and 78 normotensive controls(FokI+: Fold-; 29.5%: 70.5%)(P=O.012). Posterior wall thickness (PWT) and relative wall thickness (PWT)differed significantly among Fold--, Fold-+, Fold++ genotypes in hypertensive patients(P0.05). And so dose C825T allele between the good responders (C: T, 50.0%:50.0%