Abstract

Polymorphisms in key genes involving the folate pathway have been reported to be associated with the risk of orofacial cleft (OFC) and several studies were published with conflicting results. A meta-analysis of the previous studies of allelic association between OFC with A1298C polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene was carried out. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association between MTHFR A1298C polymorphism and OFC risk. A total of 11 studies including 1628 cases and 2676 controls were involved in this meta-analysis. No statistical relationship was found with any genetic model (C vs. A (Additive): OR = 1.14, 95%CI = 0.76-1.65, P = 0.47; CC vs. AA (homozygote): OR = 0.90, 95%CI = 0.72-1.15, P = 0.0.41; AC vs. AA (co-dominant): OR = 0.97, 95%CI = 0.85-1.11, P = 0.0.63; CC+AC vs. AA (Dominant): OR = 0.96, 95%CI = 0.84-1.1 , P = 0.51; CC vs. AC+AA (Recessive): OR = 0.93, 95%CI = 0.74-1.16, P = 0.52). The present meta-analysis supports that the common A1298C polymorphism of MTHFR gene is not risk factor for OFC.

Key words: Orofacial cleft, cleft lip, cleft palate, methylenetetrahydrofolate reductase (MTHFR), A1298C, folic acid.

Abbreviation

Orofacial cleft (OFC), methylenetetrahydrofolate reductase (MTHFR), C677T, S-adenosylmethionine (SAM).