A Novel IRF6 Frameshift Mutation in a Large Chinese Pedigree With Van der Woude syndrome

Aims: Van der Woude syndrome (VWS) is one of the most common craniofacial anomalies, causing significant functional and psychological burden to the patients. This study aimed to identify the genetic cause of VWS in a Chinese family. Methods: Whole genome sequencing (WGS) was performed to screen for pathogenic mutations. Various Bioinformatics tools were used to assess the pathogenicity of the variants. Cosegregation analysis of the candidate variant was carried out. Interpretation of variants was performed according to the American College of Medical Genetics and Genomics guidelines. Results: A novel frameshift duplication c.373_374dupAA (p.Asn125Lys fs*43) was identified in exon 4 of the interferon regulatory factor 6 (IRF6) gene in all 3 affected members, which were not found in unaffected family members. The novel mutation leads to a frameshift and a premature stop codon which caused putative truncated protein. Protein alignment indicated high evolutionary conservation of the p.N125 residue, and this mutation was predicted by online tools to be damaging and deleterious. Conclusions: This study demonstrates that the novel mutation c.373_374dupAA (p.Asn125Lysfs*43) in the IRF6 gene corresponds to the VWS in this family. The discovery of this pathogenic variant enriches the genotypic spectrum of IRF6 gene and contributes to genetic diagnosis and counseling of families with VWS.

Detection of Single Nucleotide Polymorphism rs2013162 of IRF6 Gene in Patient with Cleft Lip and Palate

Background: Cleft lip and palate are congenital disorders which induce affected individuals medically, socially and psychologically. The objective of this study was to investigate the association of Single Nucleotide Polymorphism(SNP); rs2013162 of IRF6 Gene in Patient with Cleft Lip and Palate. Materials and Methods: Fifty patients with non-syndromic CL/P were included in present study alongwith fifty individuals with no psychiatric history as controls. In all of the these individuals, search for Single nucleotide polymorphism was carried out by designing sequence specific primers. The sequence was amplified by using Real time PCR and products were investigated by visualizing high resolution melting curve upon HRM-PCR. Results: The logistic regression and Hardy-Weinberg equilibrium were applied to investigate the association of IRF6 SNP rs2013162 with disease. Results revealed no association of this polymorphism with non-syndromic CL/P. Conclusion: We found no association of IRF6 SNP rs2013162 in patients with non-syndromic CL/P. Further study is required with larger sample size to validate the findings of the present study in Pakistani population and along with this SNP other polymorphisms of the same gene should be analyzed to find out the association with the non-syndromic CL/P.

Presence of sequence and SNP variation in the IRF6 gene in healthy residents of Guangdong Province

ObjectiveThis study was to investigate the single nucleotide polymorphism (SNP) in the interferon regulatory factor 6 (IRF6) gene in healthy residents of Guangdong Province, China, for further analysis of their associations with the development of cleft lip with or without palate (CL/P).MethodologyDNA was extracted from blood samples of 13 healthy residents. IRF6 genes were sequenced and analyzed by alignment to the reference sequences in GenBank.ResultsThe IRF6 genes containing 45.21% GC were 25016–25046 bp in length, and had 2215-bp exons and a 1404-bp coding region. There were 65 SNPs, including 58 SNPs in the 5′-untranslated region or introns and 7 SNPs in the exons. These sites had two alleles, including 39 transition sites and 26 transversion sites. Five novel SNPs were identified. c. 459G>T and c. 820G>A in the coding region represented silent and Val274Ile mutations, respectively. The SNPs made two sequences (GenBank HQ875393 and JF346417).ConclusionsThe sequences and SNP profiles of the IRF6 gene in healthy residents of Guangdong Province are consistent with the one in GenBank but with slight variations. Our findings form a basis for further investigation of the association between IRF6 gene polymorphisms and CL/P in residents of Guangdong Province.