[Genetic polymorphism in tyrosine hydroxylase gene and essential hypertension in Hunan Han population]

To investigate the association of tyrosine hydroxylase (TH) C-824T polymorphism with essential hypertension (EH) susceptibility in Hunan Han population by a case-control study.

A case-control study was performed on 368 EH patients and 353 healthy controls of Han nationality recruited in Hunan province. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)was used to genotype the C-824T polymorphism.

(1) Genotype frequencies for TH-824CC and -824CT+-824TT genotypes were 89.9% and 10.1%, respectively for EH patients and 88.7% and 11.3%, respectively for the controls. No significant difference in the genotype distribution of C-824T polymorphism between the patients and controls was observed (P=0.579). Allele frequencies of TH C-824T also showed no significant difference between the patients and controls (P=0.515). (2) When adjusted by EH risk factors, results of unconditional logistic regression analysis showed that there was no association between TH C-824T polymorphism and EH susceptibility (P=0.264). (3) When stratified by gender, no significant difference in the genotype distribution of TH C-824T polymorphism was observed between the patients and controls in either male or female subjects (P=0.841 and P=0.288). (4) Diastolic blood pressure (DBP) in individuals with -824 CT+TT genotype was significantly higher than that in individuals with -824 CC genotype in the controls (P=0.015). (5) When stratified by gender, significant difference in DBP between TH C-824T CT+TT genotype and CC genotype was observed in the male (P= 0.018) but not in the female (P=0.083) controls.

There is no association between TH gene C-824T polymorphism and EH susceptibility in Hunan Han population. The TH gene C-824T polymorphism is possibly associated with increased DBP in the males in Hunan Han population.