Resumo

CASTANON, María Mercedes; LAURICELLA, Ana María; GENOUD, Valeria  e  QUINTANA, Irene Luisa. Importance of the determination of homocysteine and C667T polimorphism of methylenetetrahydrofolate reductase. Acta bioquím. clín. latinoam. [online]. 2006, vol.40, n.3, pp.335-339. ISSN 0325-2957.

Hyperhomocysteinemia (HHcy) is an independent risk factor for atherothrombotic diseases. Folic acid, vitamin B₁₂ and the enzyme methylene-tetrahydrofolate reductase (MTHFR) are some of the components involved in homocysteine (Hcy) metabolism. The aim of the present study was to evaluate the clinical usefulness of homocysteinemia determination and the C677T polymorphism analysis of the MTHFR. Homocysteine (ELISA); folic acid and vitamin B₁₂ levels (chemiluminescence) and C677T polymorphism of the MTHFR (PCR-RFLP) were evaluated in 112 healthy subjects. Twenty-five per cent of the population showed hyperhomocysteinemia (Hcy > 15 µM). Hcy levels in subjects with folate or B₁₂ deficiency were significantly higher than those found in non deficient individuals (mean: 15.8 µM or 15.6 µM vs 12.5 µM). Homozygote subjects (TT) showed higher Hcy levels than heterozygote and normal individuals (14.5 µM, 13.3 µM and 12.5 µM, respectively). Forty per cent of the B₁₂ deficient subjects, fifty-four per cent of the folate deficient individuals, forty-three per cent of the MTHFR-TT subjects and a hundred per cent of the MTHFR-TT individuals with B₁₂ deficiency turned out to be hyperhomocysteinemic. Therefore, homocysteinemia determination could evidence the presence of an atherothrombotic risk factor and likely vitamin deficiencies. Moreover, MTHFR polymorphism determination makes it possible to detect an important genetic factor of hyperhomocysteinemia.

Palavras-chave : hyperhomocysteinemia; folic acid; vitamin B₁₂; methylenetetrahydrofolate reductase.

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