Study of IRF 6 and 8q24 region in non‐syndromic oral clefts in the Brazilian population

Objectives We investigated the association between non‐syndromic oral cleft and variants in IRF 6 (rs2235371 and rs642961) and 8q24 region (rs987525) according to the ancestry contribution of the Brazilian population. Subjects and methods Subjects with oral cleft ( CL , CLP , or CP ) and their parents were selected from different geographic regions of Brazil. Polymorphisms were genotyped using a TaqMan assay and genomic ancestry was estimated using a panel of 48 INDEL polymorphisms. Results A total of 259 probands were analyzed. A TDT detected overtransmission of the rs2235371 G allele ( P  = 0.0008) in the total sample. A significant association of this allele was also observed in CLP ( P  = 0.0343) and CLP  +  CL ( P  = 0.0027). IRF 6 haplotype analysis showed that the G/A haplotype increased the risk for cleft in children (single dose: P  =   0.0038, double dose: P  =   0.0022) and in mothers (single dose: P  =   0.0016). The rs987525 (8q24) also exhibited an association between the A allele and the CLP  +  CL group ( P  = 0.0462). These results were confirmed in the probands with European ancestry. Conclusions The 8q24 region plays a role in CL /P and the IRF 6  G/A haplotype (rs2235371/rs642961) increases the risk for oral cleft in the Brazilian population.