Homozygous C677T mutation in the MTHFR gene as an independent risk factor for multiple small-artery occlusions.
BACKGROUND
Hyperhomocysteinemia is an independent risk factor for cerebrovascular disease and the homozygous C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene can induce hyperhomocysteinemia. However, the association between this 677TT genotype and ischemic stroke still remains controversial. Therefore, we carried out this study to determine whether the MTHFR TT genotype is associated with certain subtypes of ischemic stroke.


METHODS
We enrolled 195 ischemic stroke patients and 198 healthy individuals and checked their fasting plasma homocysteine levels and analyzed the C677T polymorphism in the MTHFR gene.


RESULTS
Our findings concur with previous reports that stroke occurrence is associated with hyperhomocysteinemia, but not with the 677TT genotype. However, when we re-analyzed the data based on a subtype classification, the adjusted odds ratio (AOR) and 95% confidence intervals (CI) of the 677TT genotype were found to be significantly higher in patients with small-artery occlusion than that in controls (AOR, 2.92; 95% CI, 1.01-8.48). Moreover, the AOR of the 677TT genotype was found to be much bigger in patients with multiple small-artery occlusions (AOR, 6.90; 95% CI, 1.70-27.99), but not in those with single small-artery occlusion (AOR, 1.19; 95% CI, 0.27-5.35).


CONCLUSIONS
The homozygous C677T mutation in the MTHFR gene is associated with multiple small-artery occlusions, but not with single small-artery occlusion. Our findings suggest a genetic basis for certain subtypes of ischemic stroke.
Choi
B O
BO
Department of Neurology, College of Medicine, Pochon CHA University, Sungnam, South Korea.
Kim
N K
NK
Kim
S H
SH
Kang
M S
MS
Lee
S
S
Ahn
J Y
JY
Kim
O J
OJ
Kim
S
S
Oh
D
D
D001157:Arterial Occlusive Diseases / Q000145:classification / Q000453:epidemiology / Q000235:genetics*; D001160:Arterioles; D003596:Cytosine; D005260:Female; D005838:Genotype; D006720:Homozygote; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008875:Middle Aged; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012307:Risk Factors; D013941:Thymine
D003596:Cytosine; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D013941:Thymine