Association of pre-eclampsia with hyperhomocysteinaemia and methylenetetrahydrofolate reductase gene C677T polymorphism in a Turkish population.
BACKGROUND
Hyperhomocysteinaemia is a common finding in a wide variety of pathological conditions that exhibit endothelial disturbances. In the pathogenesis of pre-eclampsia, endothelial cell activation or dysfunction has been proposed as a central feature, and the presence of hyperhomocysteinaemia in varying degrees has been detected. One of the known causes of hyperhomocysteinaemia is polymorphism in the methylenetetrahydrofolate reductase gene that lowers the activity of the enzyme.


OBJECTIVE
In the current study, we measured plasma homocysteine concentrations in pre-eclamptic pregnants, and searched for the altered methylenetetrahydrofolate reductase (MTHFR) gene in which the cytosine 677 was replaced by the thymine (C677T polymorphism).


METHODS
The study groups consisted of 64 pre-eclamptic and 47 normotensive healthy pregnant women in their third trimester. The C677T transition in the MTHFR gene was detected by HinfI restriction enzyme analysis and subsequent electrophoresis in a 3% agarose gel. Total homocysteine concentrations were measured by high performance liquid chromatography.


RESULTS
The prevalence of the homozygous mutant thymine-thymine genotype was non-significant in the pre-eclamptic group. Total homocysteine in the plasma of pre-eclamptic women was found to be increased in comparison with healthy pregnant women (P < 0.001). Any influence of the allelic distribution on plasma homocysteine concentrations was not detected in either group. However, pre-eclamptic patients bearing the non-mutated cytosine-cytosine genotype had significantly higher homocysteine levels than those with an uncomplicated pregnancy (P = 0.009), ruling out the possibility that the presence of a mutated allele is associated with the hyperhomocysteinaemia seen in pre-eclamptic women.


CONCLUSIONS
In our pre-eclamptic study population, a mild hyperhomocysteinaemia was observed. This finding seems to be a consequence of hypertension and vascular injury rather than an independent factor with a genetic origin.
Yilmaz
Hülya
H
Institute for Experimental Medical Research, Department of Molecular Medicine, Istanbul University, Istanbul, Turkey.
Unlüçerçi
Yesim
Y
Gürdöl
Figen
F
Isbilen
Elif
E
Isbir
Turgay
T
D000293:Adolescent; D000328:Adult; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006710:Homocysteine / Q000097:blood; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000201:enzymology / Q000235:genetics*; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D011110:Polymorphism, Genetic; D011225:Pre-Eclampsia / Q000097:blood*; D011247:Pregnancy; D014421:Turkey
D006710:Homocysteine; D042965:Methylenetetrahydrofolate Reductase (NADPH2)