Objective: To investigate the relationship between tryptophan hydroxylase (TPH) gene A218C in intron 7 and 5-hydroxytryptamine transporter (5-HTT) gene variable number tandem repeat (VNTR) in intron 2 and gene-linked polymorphic region (LPR) deletion/insertion polymorphism and essential hypertension (EH) in Chinese northern Han population.
Methods: A total of 280 EH patients and 200 normotensive controls were genotyped using polymerase chain reaction-restriction fragment length polymorphism technique.
Results: There were no significant differences in the frequencies of the genotypes and alleles of TPH gene A218C and 5-HTTVNTR between EH patents and controls (all P > 0.05). The genotype frequencies of SS, LS and LL in the 5-HTTLPR polymorphism was 68%, 29% and 3% in EH patients, 53%, 37% and 10% in the controls respectively (P < 0.01). The frequencies of allele S and L of the 5-HTTLPR were 82% and 18% in EH patients, 72% and 28% in the controls respectively (P < 0.01). Compared with the carriers of L allele (LS + LL), the EH risk was significantly higher in the SS homozygote (OR = 1.90, 95%CI = 1.31 - 2.77, P = 0.001). After adjustment of age, gender, body mass index, blood lipids, fasting blood glucose and blood uric acid level, the binary logistic regression analysis demonstrated that SS genotype in the 5-HTTLPR polymorphism was significantly related to occurrence of EH (OR = 1.47, 95%CI = 1.06 - 2.04, P = 0.021).
Conclusions: The SS genotype of the 5-HTTLPR might be a susceptible gene to EH, while the TPH gene A218C and 5-HTTVNTR polymorphism is not associated with EH in Chinese northern Han population.