Association of Fetal MTHFR 677C > T Polymorphism with Non-Syndromic Cleft Lip with or without Palate Risk: A Systematic Review and Meta-Analysis.

This study was conducted to estimate the precise association of fetal MTHFR 677 C > T polymorphism with risk of nonsyndromic cleft lip with or without cleft palate (NSCL ± P) using a large-scale meta-analysis.

Methods

A comprehensive literature search was performed using studies published on PubMed, Science Direct, Scopus and CNKI databases up to November 1, 2019.

Results

A total of 38 studies with 6,525 children with NSCL ± P and 8,606 controls were selected. Overall, there was a significant association between MTHFR 677 C > T polymorphism and NSCL ± P risk. Subgroup analysis by ethnicity revealed that MTHFR 677 C > T polymorphism contributed to development of NSCL ± P in Caucasian and Mixed populations, but not in Asians. When stratified by country of origin, we found a significant association in Brazilian, Turkish and Indian populations, but not in Chinese and US-American.

Conclusions

This meta-analysis provides strong evidence that fetal MTHFR 677 C > T polymorphism is significantly associated with NSCL ± P risk.