ABSTRACT
BACKGROUND: The aim of this study was to investigate the methylenetetrahydrofolate reductase (MTHFR) 677 C > T gene polymorphism in term infants born small (SGA), appropriate (AGA), and large for gestational age (LGA). METHODS: The study comprised 165 newborns with SGA, LGA and AGA. Genomic DNA was isolated from the peripheral blood. Samples were genotyped for MTHFR 677 C > T gene polymorphisms using PCR-RFLP. RESULTS: There was a statistically significant difference between the genotype and their allelic distribution of AGA, SGA, and LGA. The newborns carrying the TT genotype had higher birth weight than those carrying the CC and CT genotypes. The frequency of MTHFR 677 TT genotype and T allele was significantly higher and was found to be linked with a higher risk in LGA than in the AGA group. CONCLUSIONS: The MTHFR 677 C > T gene polymorphism can be used as a genetic marker in Turkish LGA newborns, but not in SGA.