BACKGROUND: The aim of this study was to investigate the genetic polymorphisms in the homocysteine (HCY) metabolic enzymes in the Xinjiang Uygur population who have mild cognitive impairment (MCI).

MATERIAL AND METHODS: Based on the epidemiological investigation, 129 cases of diagnosed Uygur MCI patients and a matched control group with 131 cases were enrolled for analyzing the association between the polymorphisms in the HCY metabolism related genes (C677T, A1298C, and G1968A polymorphisms in MTHFR, as well as the A2756G polymorphism in MS) and MCI by using the SNaPshot method. We then determined the homocysteine level in patients.

RESULTS: In Xinjiang Uygur subjects, the A1298C polymorphisms in MTHFR and the A2756G polymorphisms in the MS gene in the MCI group were different from those in the control group. However, the C677T and G1968A polymorphisms in the MTHFR gene in MCI patients were not different from those in the control group. Multivariate logistic regression showed that, in addition to the well-known risk factors, such as low education level, high cholesterol level, high level of low-density lipoprotein, and high homocysteine levels, the A>G mutation in the MS gene at the rs1805087 locus was another independent risk factor for MCI in the Uyghur MCI population. The risk of MCI in G allele carriers was 2.265 times higher than that in matched control individuals (95% CI: 1.205~4.256, P<0.05).

CONCLUSIONS: The genetic polymorphism of HCY metabolizing enzymes is correlated to the occurrence of MCI in the Xinjiang Uygur population. The A2756G polymorphism in the MS gene could be an independent risk factor for MCI in the Xinjiang Uygur population.

Keywords: Case-Control Studies, DNA Primers, Electrophoresis, Capillary, Homocysteine - chemistry, Homozygote, Life Style, Methylenetetrahydrofolate Reductase (NADPH2) - genetics, Mild Cognitive Impairment - genetics, Odds Ratio, Polymorphism, Genetic