These results suggest that IRF6rs2235375 SNP play a major role in the pathogenesis and risk of developing non-syndromic cleft lip with or without palate.
We identified several regions associated with subtype differentiation: cleft type differences in 8q24 (p = 1.00 × 10<sup>-4</sup> ), laterality differences in IRF6, a gene previously implicated with wound healing (p = 2.166 × 10<sup>-4</sup> ), sex differences and side of unilateral CL differences in FGFR2 (p = 3.00 × 10<sup>-4</sup> ; p = 6.00 × 10<sup>-4</sup> ), and sex differences in VAX1 (p < 1.00 × 10<sup>-4</sup> ) among others.
Mutations in IRF6 cause Van der Woude and popliteal pterygium syndrome and contribute to nonsyndromic cleft lip phenotypes but have not previously been associated with a PRS phenotype.
IRF6 mutations are the major cause of VWS; however, variants in this gene show strong association with non-syndromic oral clefts, with a higher increased risk among cases with cleft lip only (CLO).
The Van der Woude syndrome is a mendelian CL/P, accounting for about 2% of all cases and caused by mutations in the interferon regulatory factor 6 (IRF6) gene, located on 1q32.2 chromosome.
SNPs near two genes not previously associated with cleft lip with and without cleft palate (MAFB, most significant SNP rs13041247, with odds ratio (OR) per minor allele = 0.704, 95% CI 0.635-0.778, P = 1.44 x 10(-11); and ABCA4, most significant SNP rs560426, with OR = 1.432, 95% CI 1.292-1.587, P = 5.01 x 10(-12)) and two previously identified regions (at chromosome 8q24 and IRF6) attained genome-wide significance.
Mutations in the interferon regulatory factor 6 (IRF6) gene are known to cause van der Woude syndrome (VWS), a common syndromic form of oro-facial clefting characterized by the familial occurrence of mixed clefting (cleft lip with or without a cleft palate and cleft palate alone in the same family) and lower lip pits.
Mutations in Interferon Regulatory Factor 6 (IRF6) have been identified in two human allelic syndromes with cleft lip and/or palate: Van der Woude (VWS) and Popliteal Pterygium syndromes (PPS).
SNPs near two genes not previously associated with cleft lip with and without cleft palate (MAFB, most significant SNP rs13041247, with odds ratio (OR) per minor allele = 0.704, 95% CI 0.635-0.778, P = 1.44 x 10(-11); and ABCA4, most significant SNP rs560426, with OR = 1.432, 95% CI 1.292-1.587, P = 5.01 x 10(-12)) and two previously identified regions (at chromosome 8q24 and IRF6) attained genome-wide significance.
Furthermore, to test whether rs642961 could modulate IRF6 expression in vivo, we surgically collected lip skin tissues within the adjacent region of lip cleft site and found rs642961 genotypes were associated with differential levels of IRF6 mRNA and protein expression in an allele-dosage manner, providing the first evidence that rs642961 affected IRF6 expression in vivo.
SNPs near two genes not previously associated with cleft lip with and without cleft palate (MAFB, most significant SNP rs13041247, with odds ratio (OR) per minor allele = 0.704, 95% CI 0.635-0.778, P = 1.44 x 10(-11); and ABCA4, most significant SNP rs560426, with OR = 1.432, 95% CI 1.292-1.587, P = 5.01 x 10(-12)) and two previously identified regions (at chromosome 8q24 and IRF6) attained genome-wide significance.
Evidence of gene-environment interaction for the IRF6 gene and maternal multivitamin supplementation in controlling the risk of cleft lip with/without cleft palate.
Mutations in IRF6 cause Van der Woude syndrome (VWS), one of the most common syndromes associated with cleft lip (CL) with or without cleft palate (CP).
Further, results were phenotype dependent in that the IRF6 region results were most significant for families in which affected individuals have CL alone, and the FOXE1 region results were most significant in families in which some or all of the affected individuals have CL with CP.