Association of COMT gene polymorphisms with cerebral infarction in Han people of Tianjin

Abstract

Background Catechol-O-methyltransferase (COMT) has a key function in the degradation of catecholamines and inactivating estrogen. A common polymorphism in the COMT gene is guanine-adenine (G-A) point mutation on rs4680, which causes a valine (Val) substitution to methionine (Met) in 108 and (or) 158 amino acid by this gene and is responsible for lowered activity of the enzyme. The Val/Met polymorphism has been recognized to be associated with psychiatric disorders, alcohol dependence and drug side effects, but few study has been done to examine the relationship with cerebral infarction (CI). The objective of this study is to investigate the relationship between the polymorphisms of COMT gene and CI. Methods The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to detect COMT Val158Met genotype in 181 CI patients and 148 cases of controls. Meanwhile the serum levels of glucose, total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), apolipoprotein B (ApoB) and ApoA in CI group were detected. Results The frequency of Val allele (78.45%) and Val/Val genotype (61.33%) in CI was significantly higher than that in the control group (68.24% and 45.95%, P < 0.05). Further analysis showed the frequency of Val allele in CI was significant higher in men (82.52% vs 66.67%, P < 0.01), but not in women (69.83% vs 69.07%, P > 0.05) than that in the control group. The serum levels of glucose, TC, TG, LDL-C, HDL-C, ApoB, ApoA and the frequency of hypertension had no difference between Val/Val genotype and Val/Met + Met/Met genotypes (P > 0.05, for all). Conclusion The frequencies of Val allele and Val/Val genotype can be considered as genetic risk factors of male CI patients. The effect of COMT on CI is not related to blood pressure, serum lipid and glucose.