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Disease Markers
Volume 35, Issue 5, Pages 439–446
http://dx.doi.org/10.1155/2013/524106
Research Article

The MTHFR 677T Allele May Influence the Severity and Biochemical Risk Factors of Alzheimer’s Disease in an Egyptian Population

1Department of Medical Genetics, Faculty of Medicine, Umm Al-Qura University, P.O. Box 57543, Makkah 21955, Saudi Arabia
2Department of Molecular Genetics, Medical Genetics Center, Faculty of Medicine, Ain Shams University, Cairo 11566, Egypt
3Department of Psychiatry, Faculty of Medicine, Ain Shams University, Cairo 11566, Egypt
4Department of Psychology, Faculty of Arts and Humanities, King Abdulaziz University, P.O. Box 80200, Jeddah 21589, Saudi Arabia
5Department of Clinical Pathology, Medical Research Center, Faculty of Medicine, Ain Shams University, P.O. Box 80200, Cairo 11566, Egypt
6Department of Anatomy, Faculty of Medicine, Umm Al-Qura University, P.O. Box 7607, Makkah 21955, Saudi Arabia

Received 15 July 2013; Revised 18 September 2013; Accepted 20 September 2013

Academic Editor: Fabrizia Bamonti

Copyright © 2013 Nasser Attia Elhawary et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Objective. We evaluated whether the methylenetetrahydrofolate reductase (MTHFR) 677C>T marker influences the risk and severity of Alzheimer's disease (AD) and whether AD is associated with homocysteine, vitamin B12, and cholesterol levels in Egypt. Methods. Forty-three Alzheimer's cases and 32 non-AD controls were genotyped for the 677C>T polymorphism. Clinical characteristics and levels of homocysteine, vitamin B12, and cholesterol were assessed. Results. No significant differences in the frequencies of the MTHFR alleles or genotypes between AD cases and controls ( ) were identified. The 677T mutant allele was significantly overrepresented in AD cases compared to controls ( ; ). The 677T/T frequency was three times higher in AD patients than in controls, which could increase plasma homocysteine levels. Severe cases of AD were the most frequent in patients with the T/T genotype (11.6%). The effect of the MTHFR polymorphism on the risk of AD may be independent of homocysteine, vitamin B12, or even cholesterol levels. Conclusions. The MTHFR 677C>T polymorphism—especially the presence of one copy of the T allele—appears to confer a potential risk for the development of AD. The T/T genotype may contribute to hypercysteinemia as a sensitive marker.