This finding underscores the need for evaluating additional variations in IRF6 across multiple populations to better determine its role in nonsyndromic cleft lip and palate.
DNA variation in Interferon Regulatory Factor 6 (IRF6) causes Van der Woude syndrome (VWS), the most common syndromic form of cleft lip and palate (CLP).
We identified the gene that encodes interferon regulatory factor 6 (IRF6) as a candidate gene on the basis of its involvement in an autosomal dominant form of cleft lip and palate, Van der Woude's syndrome.
Since tooth agenesis is commonly found in individuals with cleft lip/palate (CL/P), we used four large cohorts to evaluate if IRF6 and TGFA interaction contributes to CL/P.
The present work steps toward resolving these issues for at least one MSX1 allele: R151S, previously identified in a single Japanese proband with unilateral cleft lip and palate.
Three of them--namely T-box transcription factor-22 (TBX22), poliovirus receptor like-1 (PVRL1), and interferon regulatory factor-6 (IRF6)--are responsible for causing X-linked cleft palate, cleft lip/palate-ectodermal dysplasia syndrome, and Van der Woude's and popliteal pterygium syndromes, respectively; they are also implied in non-syndromic cleft lip and palate.
These data provide the first mechanistic insight into the heightened caries susceptibility associated with CLP and indicate a direct role for the major CLP gene Irf6 in salivary gland development and a significant role in regulating oral immunity.
Mutations in interferon regulatory factor 6 (IRF6) account for ∼70% of cases of Van der Woude syndrome (VWS), the most common syndromic form of cleft lip and palate.
Among these, variants in interferon regulatory factor 6 (IRF6) cause syndromic orofacial clefting and contribute risk toward isolated cleft lip and palate (1/700 live births).
Significantly, we also report the identification of 2 unique missense mutations in the NME proteins in patients with CLP (NME1 R18Q in an IRF6 and GRHL3 mutation-negative patient with van der Woude syndrome and NME2 G71V in a patient with nonsyndromic CLP).
With transmission disequilibrium test analysis, cleft lip with/without cleft palate, cleft lip with palate plus cleft palate only, and all datasets combined showed evidence of association with MSX1 (p = 0.004, p = 0.037, and p = 0.001, respectively).