Mild Hyperhomocysteinemias From Deficiency of MTHFR (C677T and C1298A) in Adults and Adolescents Attending Metabolic Unit: Is There Any Necessity for Their Differentiation and Treatment?

Česká verzia

Authors: J. Hyánek; V. Maťoška; L. Dubská; B. Míková; H. Pejznochová; J. Dvořáková; L. Táborský; L. Košan; V. Martiníková; J. Privarová; J. Brtnová
Authors place of work: Metabolická ambulance, OKBHI a Lékárna Nemocnice na Homolce, Praha
Published in the journal: Klin. Biochem. Metab., 25, 2017, No. 1, p. 18-26

Summary

Goal:
incidence and monitoring of mild hypeorhomocysteinemias in patients with cardiovascular risk attending the metabolic unit.

Type of Study:
retrospective analysis of a metabolic study.

Patients and Methods:
44 patients – from metabolic unit- selected homozygotes or heterozygotes confirmed by molecular-genetics methods for polymorphism of methylenetetrahydrofolate reductases (MTHFR C677T and A1298C) and accompanied with mild hyperhomocysteinemia (> 30 µmol/l of homocysteine in blood) were further metabolically analyzed and documented.

Results:
authors discuss and postulate till now not described form of mild hyperhomocysteinemia caused only by decreased enzymatic activity of MTHFR as a relatively often metabolic disturbance of folate metabolism. Due to defficient enzyme aktivity of MTHFR C677T in TT homozygotes (< 40%) the levels of plasmatic folates are decreased and the remethylation of homocysteine in the methionine cyclus is diminished.The negative correlation of lowered plasmatic folate with hyperhomocysteinemia in TT homozygotes (r= -0.853) and in CT heterozygotes (r = -0.635) was proved. In healthy control (r = +0.259). Supplementation of these patients with folic acid effectively increased folate plasmatic levels and decreased homocysteine levels. Typical clinical cases are documented with metabolic schemes or pedigrees. The therapeutical effect of homocysteine decrease on prognosis of cardiovascular risk has not been till now observed.

Conclusion:
mild hyperhomocysteinemias from folate defficiency due to homozygozity or heterozygozity of MTHFR in the Czech population represent the 3^rd most cause of hyperhomocysteinemias: 1^st kidney diseases, 2^nd deficiency of holotranscobalamin. All mild hyperhomocysteinemias detected within routine laboratory practice must be differenciated and with adequate therapeutical effort established. Otherwise the routine estimation of homocysteine could be missused only for economical purposes.

Key words:
Hyperhomocysteinemia, Methylenetetrahydrofolate Reductase, MTHFR, Plasma Folate Cardiovascular Risk, Spina Bifida.

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