The relationship between cystatin C gene G73A locus and appolipoprotein E gene polymorphisms and vascular cognitive impairment

Abstract

Objective To investigate the relationship of cystatin C gene (CST3) G73A locus and apolipoprotein E (APOE) gene polymorphisms with vascular cognitive impairment(VCI). Methods A case-control study was conducted to collect outpatients and inpatients of Neurology department, and healthy subjects in the same period in Affiliated Hospital of Qingdao University from January to June 2015, including 155 patients with VCI, 210 patients with cerebral infarction (CI) without cognitive impairment and 250 healthy subjects as control group (ND). Polymerase chain reaction/restrictive fragment length polymorphism (PCR/RFLP) was used to detect the polymorphism of CST3 G73A and APOE genes. The chi-square test was used to perform genotype and allele analysis. The effects of these two gene polymorphisms on VCI were analyzed by multivariate Logstic regression which to correct the influencing factors. Results No statistical differences were demonstrated in CST3 G73A locus genotype frequencies (χ2=3.95, P=0.14) and allele frequencies (χ2=3.95, P=0.14). Compared with non-carrying type, the risk of developing VCI in APOE e4/4 gene-carrying type is 4.98 times higher than that of CI group (P<0.01, 95%CI: 1.94-12.80), while 5.68 times higher than that of ND group (P<0.01, 95%CI: 2.22-14.60). After correcting the risk factors of the CST3 gene G73A locus and the APOE gene by multiple Logistic regression, the results showed that when the G73A locus was AA mutant, the risk of VCI in the APOE e4/4 gene-carrying type was 7.19 times higher than that of the CI group (corrected OR: 6.30, 95%CI: 1.34-29.60, P=0.013), while 8.22 times higher than that of the ND group (OR: 7.26, 95%CI: 1.55-34.10, P=0.008). Conclusion The AA gene mutation of G73A locus in CST3 may increase the risk of VCI in APOE e4/4 gene-carrying type. Key words: Cystatin C; Apolipoproteins E; Vascular cognitive impairment