Transforming Growth Factor Alpha Taq I Polymorphisms and Nonsyndromic Cleft Lip and/or Palate Risk: A Meta-Analysis

A series of epidemiological studies were conducted to investigate the association between transforming growth factor alpha ( TGFA) polymorphism and nonsyndromic cleft lip and/or palate (CL/P) risk, but the findings remain conflicting. The present meta-analysis summarizes the association between the TGFA Taq I polymorphisms and nonsyndromic CL/P risk.

We searched PubMed, EMBASE, Web of Science, and Chinese Biomedical Literature databases from their inception to May 1, 2015. Fixed-effects or random-effects models were used to calculate the pooled odds ratio for two genetic comparisons (heterozygous mutation versus wild type, homozygous mutation versus wild type). All of the statistical tests were conducted by STATA 10.0 (StataCorp, College Station, TX).

A total of 26 case-control studies were identified for this meta-analysis. There was evidence of a significant association between the TGFA Taq I polymorphism and nonsyndromic CL/P risk in the overall population. The TGFA polymorphism was associated with nonsyndromic CL/P susceptibility in Asian populations under any of genetic models. However, in subgroup analysis, we did not find a significant association of TGFA gene polymorphisms with a reduced cancer risk in White and other populations and (recessive model, odds ratio = 2.37, 95% confidence intervals = 0.92-6.07; odds ratio = 3.45, 95% confidence intervals = 1.07-11.09, respectively).

Our study indicates that the TGFA gene polymorphism might be associated with nonsyndromic CL/P susceptibility. However, these findings still need to be confirmed by single, large, well-designed prospective studies.