Methylene Tetrahydrofolate Reductase Polymorphisms and Homocysteine Level in Heart Defects

Background: While several single nucleotide polymorphisms are known to influence the metabolism of folate, the methylene tetrahydrofolate reductase (MTHFR) gene has been the most extensively studied. The aim of this study was to investigate the relationship between the MTHFR polymorphisms 1298A>C and 677C>T and congenital heart disease. In addition, the relationship between these gene polymorphisms and homocysteine level was determined in Turkish subjects.

Methods: Patients with non-syndromic congenital heart defects who were admitted to the Pediatric Cardiology Unit at Hacettepe University Ihsan Dogramaci Children's Hospital, Ankara, Turkey between June 2002 and June 2003 were recruited for the study. A total of 163 children with congenital heart defects (mean age, 7.63 ± 6.03 years; M/F, 93/70) and 93 healthy controls were analyzed.

Results: When evaluated either separately or together, there were no differences in the frequency of MTHFR 677C>T or 1298A>C polymorphisms between the children with congenital heart defects and the control group. The results were the same when considering only conotruncal defects. Those with the 677C>T polymorphism had significantly lower homocysteine level (P = 0.004), but the 1298A>C polymorphism was not related to homocysteine level.

Conclusion: No relationship was found between congenital heart defects and 1298A>C or 677C>T polymorphisms. The 677C>T polymorphism was related to low homocysteine level. Because there is often much heterogeneity between populations, this study should be conducted in different populations and with larger numbers of participants.