The regulatory region polymorphisms of the MTHFR gene are not associated with Alzheimer's disease.Dement Geriatr Cogn Disord. 2004; 17(3):147-50.DG
Recent epidemiological studies have emphasized the impact of elevated blood homocysteine levels on the pathogenesis of Alzheimer's disease (AD). In spite of a significant impact of a MTHFR C677T polymorphism on the blood homocysteine levels, the association between the C677T polymorphism and AD remains controversial. Therefore, other unidentified genetic factor(s) that regulate blood homocysteine levels may exist. Here, we have analyzed the 5'-upstream region of the MTHFR gene and examined AD patients (n = 223) and nondemented individuals (n = 323) for polymorphisms in the 5'-upstream region of the MTHFR gene. We identified two polymorphisms (-713G/A and -393C/A, upstream of the start codon). We found no significant relationship between AD and the 5'-upstream region polymorphisms of the MTHFR gene. Thus, our study does not reinforce the hypothesis of an independent involvement of the MTHFR gene upstream region polymorphisms in AD risk.