Variation in IRF6 contributes to nonsyndromic cleft lip and palate

Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common craniofacial birth defect which results in lifelong medical and social consequences. While there have been a number of attempts to identify the genes responsible for this disorder, the results have not been consistent among populations and no single gene has been identified as playing a major susceptibility role. Van der Woude syndrome, a disorder characterized by lower-lip pits with or without cleft lip/palate, results in many cases from mutations in the interferon regulatory factor 6 (IRF6) gene. Recently, Zucchero et al. [2004: N Engl J Med 351:769-780] detected an association between SNPs in IRF6 and NSCLP in a number of different populations. A subsequent study by Scapoli et al. [2005: Am J Hum Genet 76:180-183] confirmed this association in an Italian population. We examined the same SNPs as Scapoli et al. [2005] in our large, well-characterized sample of NSCLP families and trios, and also detected an altered transmission of IRF6 alleles. This additional confirmation further strengthens the IRF6 association and suggests that IRF6 plays a role in NSCLP susceptibility.