Association between IRF6 SNPs and oral clefts in West China

Abstract

Analyses of previous data have confirmed the contribution of the IRF6 gene to susceptibility to non- syndromic oral clefts (NSOC) in some populations. We tested for associations between the rs2013162, rs2235375, and rs2235371 polymorphisms in IRF6 and the risk of NSOC, using both case-parent trio and case-control designs on samples from western China. Our study group consisted of 332 persons with NSOC, their parents (289 mothers and 243 fathers for 206 complete trios for these three SNPs), and 174 control individuals. We found strong evidence of over- and under-transmission of the C allele (the Val allele) at rs2235371, and the C allele at rs2235375 in cleft case-parent trios (P = 0.013 and P = 0.000, respectively). There were significant differences in the frequency distributions of both genotypes and alleles when cases were compared with control infants at rs2235371 and rs2235375. Five specific haplotypes showed significant over- and under-transmission. These results further support a role for IRF6 variants in western Chinese populations.

Figure.

Restriction fragment length polymorphism patterns for IRF6 rs2013162 (A), rs2235375 (B), and rs2235371 (C). (A) Lane M is the 50-bp DNA marker (pUC 19 DNA/MspI), with the arrowhead denoting the 250-bp band. Lanes 1 and 6 represent individuals who are homozygous AA, 3 and 4 represent homozygous CC, and 2 and 5 represent heterozygous CA, respectively. (B) Lane M is the 50-bp DNA marker, with the arrowhead denoting the 150-bp band. Lane 1 represents individuals who are homozygous C, 3 represents homozygous GG, and 2 and 4 represent heterozygous CG, respectively. (C) Lane M is the 50-bp DNA marker, with the arrowhead denoting the 250-bp band. Lane 2 represents individuals who are homozygous TT, 1 and 4 represent homozygous CC, and 3 represents heterozygous CT, respectively.