Association Between MTHFD1 1958G > A Variant and non-Syndromic Cleft lip and Palate: An Updated Meta-Analysis

Introduction: Non-syndromic cleft lip and palate (NSCLP) is one of the most common and challenging congenital deformities worldwide. Previous research has linked the methylenetetrahydrofolate dehydrogenase1 (MTHFD1) gene to orofacial cleft (OFC) susceptibility via a complex metabolism. Studies analyzing the MTHFD1 1958G > A variant and NSCLP are contradictory. This study aims to evaluate the association between the MTHFD1 1958G > A variant and NSCLP by meta-analysis.

Methods: PubMed, Web of Science, MEDLINE, and Google Scholar databases were searched to retrieve the eligible studies. A fixed- or random-effect model was used to calculate pooled odds ratio (OR) and 95% confidence interval (CI). All analyses were calculated by Metagenyo software. To detect heterogeneity, the Cochrane Q and I² statistics were used. The publication bias was estimated using funnel plots and Egger's test.

Results: Our study suggested that the MTHFD1 1958G > A variant allele "A" does not appear to increase the risk of NSCLP (A vs G random effect model: Overall P = .501, OR = 1.07, CI = 0.88-1.31; Asians P = .245, OR = 1.29, CI = 0.84-1.97; Caucasians P = .658, OR = 0.95, CI = 0.76-1.19). Similarly, mutant genotypes also did not exhibit increased risk for NSCLP in the overall populations as well in subgroup analysis by ethnicity (AA + AG vs GG: Overall P = .684, OR = 1.06, CI = 0.80-1.39; Asians P = .240, OR = 1.47, CI = 0.77-2.78; Caucasians P = .923, OR = 0.99, CI = 0.85-1.16).

Conclusions: Our data suggest no association between the MTHFD1 1958G > A variant and NSCLP. Additional well-designed studies are needed to better understand the role of MTHFD1 polymorphisms in the etiopathogenesis of NSCLP.