Association of the polymorphisms and non-syndromic cleft lip with or without cleft palate: evidence from a meta-analysis.

Objective: This meta-analysis was conducted with the aim of investigating the association between gene polymorphisms and non-syndromic cleft lip (CL) with or without cleft palate (NSCL/P) predisposition.

Methods: A comprehensive literature search was performed in six online databases including PubMed, Embase, ISI Web of Science, CENTRAL, CNKI, and Wanfang from inception up to June 2018 without language restriction. Pooled odds ratios (ORs) and corresponding 95% confidence intervals (95%CIs) were calculated under allele model of inheritance to indicate the association between polymorphisms and NSCL/P.