Nonsyndromic cleft lip with or without cleft palate (NSCL/P) is the most common orofacial birth defect with a wide range prevalence among different populations. Previous association studies with populations from Europe and Asia have identified putative susceptibility markers for NSCL/P in fibroblast growth factor 12 (FGF12), vinculin (VCL), connexin 43 (CX43) and in a region close to the ventral anterior homeobox 1 (VAX1) gene. However, there have thus far been no studies of these markers in NSCL/P Brazilian patients, and as the genetic ancestry of the Brazilian population is highly varied, the predisposition to those disease markers can be different.

Herein we conducted a structured association study conditioned on the individual ancestry proportions to determine the role of 16 polymorphic markers within those genes in 300 patients with NSCL/P and 385 unaffected controls.

None of the alleles and genotypes showed association with NSCL/P, though there was a significant association of the haplotype formed by VAX1 rs10787760, rs6585429 and rs1871345 polymorphisms with NSCL/P that did not persist Bonferroni correction for multiple tests.

Our results are consistent with a lack of involvement of FGF12, VCL and CX43 variants with NSCL/P pathogenesis in Brazilian patients. Furthermore, the higher frequency of a haplotype of VAX1 with NSCL/P patients suggests a low penetrant gene for oral cleft, and warrants further studies.