title: Metabolic effects of C677T and A1298C mutations at the MTHFR gene in Brazilian children with neural tube defects.
abstract: BACKGROUND
  Methylenetetrahydrofolate reductase (MTHFR) deficiency leads to impairment in folate metabolism and is implicated as a risk factor for neural tube defects (NTDs). Both C677T and A1298C MTHFR mutations are associated with NTDs, in some populations.
  
  
  METHODS
  The frequencies of the C677T and A1298C MTHFR mutations were determined in 25 children with NTDs, case mothers and 75 healthy individuals from Sao Paulo City. Both C677T and A1298C mutations were analyzed by PCR-FLRP. The effects of MTHFR mutations on folate, vitamin B12 and homocysteine concentrations were also evaluated.
  
  
  RESULTS
  C677T and A1298C allele frequencies in NTDs children and mothers were similar to that found in controls. Eleven in 23 NTDs patients and 10 in 21 NTDs mothers had folate or vitamin B12 concentrations in the lower end of the normal range. In NTDs children, C677T MTHFR genotypes did not affect vitamins and homocysteine concentrations, but plasma homocysteine was higher (p=0.028) in patients with 1298AA MTHFR genotype. Moreover, 677CT/1298AA haplotype was associated with lower vitamin B12 concentrations (p<0.05) in NTDs children.
  
  
  CONCLUSIONS
  MTHFR gene mutations may affect vitamin B12 and homocysteine metabolism in Brazilian children with NTDs.
authors.affiliation: Department of Clinical and Toxicological Analysis of the Faculty of Pharmaceutical Sciences, University of Sao Paulo, Ave Prof. Lineu Prestes 580, B1 17, 05508-900, Brazil.
authors.forename: Andrea L A
authors.initials: AL
authors.lastname: Cunha
authors.forename: Mario H
authors.initials: MH
authors.lastname: Hirata
authors.forename: Chong A
authors.initials: CA
authors.lastname: Kim
authors.forename: Elvira M
authors.initials: EM
authors.lastname: Guerra-Shinohara
authors.forename: Kymio
authors.initials: K
authors.lastname: Nonoyama
authors.forename: Rosario D C
authors.initials: RD
authors.lastname: Hirata
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D005260:Female; D006710:Homocysteine / Q000097:blood; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D008875:Middle Aged; D020125:Mutation, Missense / Q000235:genetics; D009436:Neural Tube Defects / Q000201:enzymology* / Q000235:genetics*; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000172:deficiency* / Q000235:genetics*; D014815:Vitamins / Q000097:blood
chemical_list: D014815:Vitamins; D006710:Homocysteine; D000587:Oxidoreductases Acting on CH-NH Group Donors; D042965:Methylenetetrahydrofolate Reductase (NADPH2)