Clinical and genetic features of Chinese kindreds with Van der Woude syndrome caused by interferon regulatory factor 6 mutation / 华西口腔医学杂志

OBJECTIVE@#This study aimed to investigate the clinical phenotype and genetic characteristics of Chinese families with Van der Woude syndrome (VWS).@*METHODS@#Clinical manifestations between 14 families and within each family were recorded. Possible inheritance modes and pathogenic genes were analyzed. Phenotypic distribution and gene frequencies were calculated.@*RESULTS@#Of the pedigrees investigated, an autosomal dominant inheritance pattern was suggested. All patients had typical symptoms. The pathogenic gene was interferon regulatory factor 6 (IRF6). Phenotypic distribution frequencies were as follows: lip pits (91.9%), cleft lip and/or palate (73.0%), and hyperdontia (8.1%). There were significant differences in clinical phenotypes among individuals of different families and individuals of the same family.@*CONCLUSIONS@#VWS in a Chinese population was dominantly inherited with high penetrance and variable expressivity. The pathogenic gene was IRF6. VWS in a Chinese population was genotyped as VWS1.

IRF6, RYK, and PAX9 expression in facial tissue of children with cleft palate / Expresión de IRF6, RYK y PAX9 en el tejido facial de niños con paladar fisurado

Cleft lip and palate (CLP) is a congenital anomaly characterized by the inappropriate fusion of the upper lip, alveolus, and secondary palate. This study investigated whether expression of interferon regulatory fac tor 6 (IRF6), receptor-like tyrosine kinase (RYK), and paired-box 9 (PAX9), which are essential for the normal development and morphogenesis of craniofacial structures, is dysregulated in children with CLP. Oral mucosa tissue samples were obtained from patients with complete bilateral (CB) CLP (n= 19) during corrective plastic surgery and unaffected control subjects (n= 7). IRF6, RYK, and PAX9 expression was assessed by immunohistochemistry, and data were analyzed with the Mann-Whitney test. In patients, IRF6 immunoreactivity in the connective tissue was moderate to high, but the overall number of IRF6-positive oral epithelial cells was lower than that in controls (z= -3.41; P= 0.01). RYK expression was observed only sporadically in the oral epithelium of 4 patients, in contrast to the control group (z= -3.75; P< 0.001). PAX9-positive epithelial cells were present in low to moderate numbers in patients with CBCLP, while an abundance of these cells was observed in the basal layer of the oral epithelium in controls (z= -3.60; P<0.001). IRF6 is the main connective tissue regulatory factor in CBCLP, and its low level of expression in the oral epithelium suggests a reduced potential for epitheliocyte differentiation, while low PAX9 and RYK expression may explain the decreased cell migration and cleft remodeling in CBCLP.

La fisura labial y palatina (FLP) son anomalías congénitas caracterizadas por la fusión inadecuada del labio superior, alvéolo y paladar secundario. En este estudio se investigó si en niños con FLP hay una desregulación de la expresión del factor regulador de interferón 6 (IRF6), del receptor de la tirosina quinasa (RYK), y del factor de transcripción PAX9, que son esenciales para el desarrollo normal y la morfogénesis de las estructuras craneofaciales. Se obtuvieron muestras de la mucosa oral de pacientes con FLP completa bilateral (CB) (n= 19), tomadas durante la realización de cirugía plástica correctiva, y de sujetos de control no afectados (n= 7). Se evaluó la expresión de IRF6, RYK y PAX9 por inmunohistoquímica, y los datos se analizaron con la prueba de Mann-Whitney. En los pacientes, la inmunoreactividad de IRF6 en el tejido conectivo fue de moderada a alta, pero el número total de células epiteliales orales positivas para IRF6 fue menor que en los controles (z= -3,41; P= 0,01). La expresión de RYK se observó sólo esporádicamente en el epitelio oral de 4 pacientes, en contraste con el grupo control (z= -3,75; P<0.001). Células epiteliales positivas para PAX9 estaban presentes en números bajos a moderados en pacientes con FLP completa bilateral, mientras que se observó una abundante cantidad de estas células en la capa basal del epitelio oral en los controles (z= -3,60; P<0,001). IRF6 es el principal factor regulador del tejido conectivo con FLP completa bilateral, y su bajo nivel de expresión en el epitelio oral sugiere un potencial reducido para la diferenciación del epitelio, mientras que la expresión baja de PAX9 y RYK pueden explicar la disminución de la migración celular y la remodelación de la fisura con FLP completa bilateral.

Significant association between SNPs in IRF6 and non-syndromic cleft lip with or without cleft palate in West China / 实用口腔医学杂志

Objective:To study the association between the rs2013162 and rs2235375 polymorphisms in IRF6 and risk of NSCL/P in west Chinese population. Methods: The study group consisted of 332 NSCL/P patients, their parents (289 mothers, 243 fathers and 206 complete families), and 174 controls. PCR-RFLP method was used to identify genotypes and both case-parent and case-control designs were carried out on samples from west China. Results: There were significant differences in the frequency distributions of both genotypes and alleles when cases were compared with control infants at the rs2235375(P<0.01, P<0.01 respectively). We found strong evidence of over-transmission of the G allele at rs2235375 in cleft case-parent trios(P<0.01). Five specific haplotypes showed significant over-and under-transmission. Conclusion: These results suggest IRF6 variants play a role in NSCL/P in west Chinese populations.