title: [Hyperhomocystinemia and 677C T methylenetetrahydrofolate reductase polymorphism as a cardiovascular risk factor in childhood].
abstract: BACKGROUND
  Factors related to hyperhomocystinemia in the pediatric population of our geographical area with a parental history of premature coronary disease (PCD) are not well known.
  
  
  OBJECTIVE
  To evaluate the possible association between plasma total homocysteine (tHcy), the B vitamins involved in its metabolism (folate, vitamin B12 and B6), and 677C T polymorphism of methylenetetrahydrofolate reductase (MTHFR) in a group of children with a parental history of PCD.
  
  
  METHODS
  A cross-sectional analytical study of 80 children (aged 5-18 years old) with a parental history of PCD was performed. Values found in these children were compared with reference values for similar age groups. Plasma tHcy and vitamin B6 were evaluated by high-performance liquid chromatography with fluorometric detection. Folate and vitamin B12 concentrations were determined by radioimmunoassay. Detection of 677C T polymorphism of MTHFR was performed using polymerase chain reaction amplification and Hinfl digestion. Statistical analysis was performed using the SPSS program, version 10.0. Concentrations of tHcy and vitamins were compared using the Mann-Whitney U-test and Spearman's correlation coefficient. The association between phenotype, hyperhomocystinemia and low vitamin concentrations was analyzed using the chi-squared test. ResultsPlasma tHcy values in the children aged more than 10 years with a parental history of PCD were significantly higher (p < 0.001) than the reference values. Vitamin B12 levels were significantly lower (p 0.015), but neither folate nor vitamin B6 levels differed from the reference values. A negative correlation (p < 0.0001) was observed between tHcy and folate (r 0.47) and between tHcy and vitamin B12 levels (r 0.51). Eighty percent of the children with the TT genotype of MTHFR showed hyperhomocystinemia. Suboptimal vitamin B levels were also associated with the TT genotype of MTHFR.
  
  
  CONCLUSIONS
  Hyperhomocystinemia detected in children with a parental history of PCD is associated with the TT genotype of MTHFR and with low folate levels. Because hyperhomocystinemia can be corrected by vitamin B supplementation, tHcy determination is recommended in the offspring of patients with PCD.
authors.affiliation: Servicio de Pediatría, Hospital Universitario Sant Joan de Déu, Barcelona, Spain. mainou@medicina.ub.es
authors.forename: C
authors.initials: C
authors.lastname: Mainou Cid
authors.forename: N
authors.initials: N
authors.lastname: García Giralt
authors.forename: M A
authors.initials: MA
authors.lastname: Vilaseca Buscà
authors.forename: I
authors.initials: I
authors.lastname: Ferrer Codina
authors.forename: José F
authors.initials: JF
authors.lastname: Meco López
authors.forename: A
authors.initials: A
authors.lastname: Mainou Pintó
authors.forename: X
authors.initials: X
authors.lastname: Pintó Sala
authors.forename: D
authors.initials: D
authors.lastname: Grinberg Vaisman
authors.forename: S
authors.initials: S
authors.lastname: Balcells Comas
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003327:Coronary Disease / Q000235:genetics*; D003430:Cross-Sectional Studies; D003596:Cytosine; D005260:Female; D006801:Humans; D020138:Hyperhomocysteinemia / Q000201:enzymology / Q000235:genetics*; D008297:Male; D008754:Methylenetetrahydrofolate Dehydrogenase (NADP) / Q000235:genetics*; D011110:Polymorphism, Genetic; D014443:Tyrosine
chemical_list: D014443:Tyrosine; D003596:Cytosine; D008754:Methylenetetrahydrofolate Dehydrogenase (NADP)