Study of the determination of the polymorphic variants -1298A> C and -677C> T of the gene of methylenetetrahydrofolatereductase (MTHFR) in predicting the congenital pathology of the maxillofacial area. Objectives. To study the role of polymorphisms -1298A> C and -677C> T of the MTHFR folate cycle gene in the formation in patients with congenital pathology of the maxillofacial area. Methods. We analyzed the frequency distribution of genotypes and alleles according to polymorphism 1298 A> C of the MTHFR gene. We also analyzed the frequency distribution of genotypes and alleles according to polymorphism 677C> T of the MTHFR gene in a group of patients (n = 37) with congenital pathology of the maxillofacial area and control group (n = 46). Results. Genetic marker of the disease congenital pathology of the maxillofacial area is the genotype of the SS polymorphic locus 1298 A> C of the MTHFR gene. Its frequency was 13.6% against 2% in the control. In the calculation of odds ratios index following values were obtained: OR-7,32; CI95% -1.51-48.51. The results confirm the predictive value of a mutant CC genotype -1298A>C MTHFR gene as a risk of congenital disease pathology maxillofacial area. There was no statistically significant differences between patients and the control group for the distribution of frequencies of genotypes and alleles of the locus 677 C> T of the MTHFR gene. Conclusions. Genetic marker of congenital pathology of the maxillofacial area is the genotype of the SS polymorphic locus 1298 A> C of the MTHFR gene. The obtained data can be used, to predict a congenital pathology of the maxillofacial area with the purpose of treatment and prevention.