Association analysis between the interleukin-6 gene promoter-174G/C polymorphism with Alzheimer disease and vascular dementia in Guangzhou

Objective To investigate the association between interleukin-6(IL-6)gene promoter-174G/C polymorphism with Alzheimer disease(AD)and vascular dementia(VD)in Han Chinese.Methods The subjects came from an epidemiological investigation.Association study was performed in 161 AD patients,54 VD patients and 247 healthy old individuals in Guangzhou,China.The-174C/G polymorphism of IL-6 gene promoter was analyzed with the technique of polymerase chain reaction-restriction fragment length polymorphism.Results (1)The genotype C/C wosn't detected in all subjects.(2)No significant difference in distribution of IL-6-174c/G polymorphism between AD patients and controls Was observed(P>0.05),even after stratification by Apo E e4 status.(3)The frequencies of IL-6 genotype C/G(3.7%)and allele C(1.9%)in the VD patients were significant higher than that in controls(0)(Fisher's exact test,P<0.05).(4)The frequency of Apo E s-4 allele(23.9%)in moderate or severe AD patients was significant higher than controls(14.7,P<0.05).Conclusion The IL-6 gene-174C/G polymorphism may be not associated with AD,but possibly with VD. Key words: Alzheimer disease; Dementia,vascular;  Interleukin-6:Polymorphism,restriction fragment length;  Case-control studies