Zhang Ying-dong, Ke Xiao-yan, Shen Wei, Liu Yang
Neuropsychiatric Institute, Nanjing Brain Hospital, Nanjing Medical University, Nanjing 210029.
Chin Med Sci J. 2005 Dec;20(4):247-51.
To investigate the relationship of plasma homocysteine (Hcy) levels and the gene polymorphisms of N5, N10-methylenetetrahydrofolate reductase (MTHFR), cystathionine beta-synthase (CBS) with Alzheimer's disease (AD).
Plasma Hcy levels were measured by means of high voltage capillary electrophoresis with ultra-violet detection, the polymorphisms of C677T in exon 4 of MTHFR gene and 844ins68 in exon 8 of CBS gene were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 105 AD patients and 102 non-AD controls. All controls were excluded from cardiocerebrovascular disorders and other diseases.
The plasma Hcy level in AD patients (16.04 +/- 3.84 micromol/L) was significantly higher than that in the controls (11.94 +/- 3.87 micromol/L, P < 0.001). There were no significant differences of the genotype and allele frequencies of MTHFR C677T mutation and CBS 844ins68 mutation between the patients and controls. However, the T allele of MTHFR gene was found to relate with the plasma Hcy level increase in all subjects.
The elevated plasma Hcy level in AD patients is probably involved in the pathogenesis of AD, which may be due to the environmental factor rather than genetic factors of the mutations of MTHFR and CBS.
探讨血浆同型半胱氨酸（Hcy）水平及N5，N10-亚甲基四氢叶酸还原酶（MTHFR）、胱硫醚β合成酶（CBS）基因多态性与阿尔茨海默病（AD）的关系。
采用高压毛细管电泳-紫外检测法测定血浆Hcy水平，应用聚合酶链反应-限制性片段长度多态性（PCR-RFLP）技术分析105例AD患者和102例非AD对照者MTHFR基因第4外显子C677T多态性及CBS基因第8外显子844ins68多态性。所有对照者均排除心脑血管疾病及其他疾病。
AD患者血浆Hcy水平（16.04±3.84μmol/L）显著高于对照组（11.94±3.87μmol/L，P<0.001）。患者与对照组之间MTHFR C677T突变及CBS 844ins68突变的基因型和等位基因频率无显著差异。然而，在所有受试者中发现MTHFR基因的T等位基因与血浆Hcy水平升高有关。
AD患者血浆Hcy水平升高可能参与AD的发病机制，这可能是由于环境因素而非MTHFR和CBS突变的遗传因素所致。
