Analysis of a Chinese pedigree affected with van der Woude syndrome due to variant of IRF6 gene / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic characteristics of a Chinese pedigree affected with van der Woude syndrome (VWS).@*METHODS@#A proband who had visited the Drum Tower Hospital Affiliated to Nanjing University Medical School in May 2020 for "two previous pregnancies with cleft lip and palate" was selected as the study subject. Trio-whole exome sequencing (trio-WES) was carried out for the patient. Candidate variants were verified by Sanger sequencing of her pedigree members (8 individuals from four generations) and bioinformatic analysis. Chromosomal microarray analysis (CMA) was used to rule out copy number variations in the fetuses.@*RESULTS@#Trio-WES revealed that the proband and her father had both harbored a heterozygous c.742G>T (p.G248C) missense variant of the IRF6 gene, for which her mother was of the wild type. The variant was located in a region with important functions and has not been reported previously. Prediction with several software suggested that it is likely to have a significant impact on the protein structure/function and is highly correlated with the specific phenotypes in this pedigree. Sanger sequencing confirmed co-segregation of the genotypes and phenotypes in the pedigree. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), this variant was rated as likely pathogenic (PM1+PM2_Supporting+PP1+PP3+PP4). Based on the above results, pre-implantation genetic diagnosis was carried out for the proband, which has led to birth of a healthy offspring with normal results for both site testing and CMA.@*CONCLUSION@#The IRF6: c.742G>T (p.G248C) heterozygous variant probably underlay the VWS in this pedigree. Above finding has also enabled reproductive guidance for the proband.

IRF4 and IRF8 expression are associated with clinical phenotype and clinico-hematological response to hydroxyurea in essential thrombocythemia / 医学前沿

The morbidity and mortality of myeloproliferative neoplasms (MPNs) are primarily caused by arterial and venous complications, progression to myelofibrosis, and transformation to acute leukemia. However, identifying molecular-based biomarkers for risk stratification of patients with MPNs remains a challenge. We have previously shown that interferon regulatory factor-8 (IRF8) and IRF4 serve as tumor suppressors in myeloid cells. In this study, we evaluated the expression of IRF4 and IRF8 and the JAK2V617F mutant allele burden in patients with MPNs. Patients with decreased IRF4 expression were correlated with a more developed MPN phenotype in myelofibrosis (MF) and secondary AML (sAML) transformed from MPNs versus essential thrombocythemia (ET). Negative correlations between the JAK2V617F allele burden and the expression of IRF8 (P < 0.05) and IRF4 (P < 0.001) and between white blood cell (WBC) count and IRF4 expression (P < 0.05) were found in ET patients. IRF8 expression was negatively correlated with the JAK2V617F allele burden (P < 0.05) in polycythemia vera patients. Complete response (CR), partial response (PR), and no response (NR) were observed in 67.5%,10%, and 22.5% of ET patients treated with hydroxyurea (HU), respectively, in 12 months. At 3 months, patients in the CR group showed high IRF4 and IRF8 expression compared with patients in the PR and NR groups. In the 12-month therapy period, low IRF4 and IRF8 expression were independently associated with the unfavorable response to HU and high WBC count. Our data indicate that the expression of IRF4 and IRF8 was associated with the MPN phenotype, which may serve as biomarkers for the response to HU in ET.

Identification of pathogenic variant in a Chinese pedigree affected with non-syndromic cleft lip and palate / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a Chinese pedigree affected with non-syndromic cleft lip and cleft palate (NSCLP).@*METHODS@#With informed consent obtained, members of the pedigree were subjected to clinical examination and history taking to exclude syndromic cleft lip and palate. One affected member was subjected to whole-exome sequencing and bioinformatics analysis. Candidate variant was verified by Sanger sequencing and co-segregation analysis of her family members and 100 unrelated healthy individuals.@*RESULTS@#Whole-exome sequencing and co-segregation analysis showed that all affected members of this pedigree have carried a heterozygous missense c.253A>G (p.Cys85Arg) variant in exon 4 of the IRF6 gene, which has co-segregated with the phenotype and was not found among the 100 unrelated healthy individuals.@*CONCLUSION@#The missense c.253A>G variant in exon 4 of the IRF6 gene probably underlay the NSCLP in this pedigree.

IRF6 polymorphisms in Brazilian patients with non-syndromic cleft lip with or without palate / Polimorfismos do gene IRF6 em pacientes brasileiros com fenda labial não sindrômica com ou sem fenda palatina

Abstract Introduction: Non-syndromic orofacial clefts have a complex etiology due to the contribution from both genetic and environmental risk factors, as well as the interaction between them. Among the more than 15 susceptibility loci for non-syndromic orofacial clefts with considerable statistical and biological support, the IRF6 is the most validated gene by the majority of studies. Nonetheless, in genetically heterogeneous populations such as Brazilian, the confirmation of association between non-syndromic orofacial clefts and IRF6 common variants is not a consolidated fact and unrecognized IRF6 variants are poorly investigated. Objective: The aim of this study was to investigate the association of IRF6 polymorphisms with non-syndromic orofacial clefts development in a population from northeast Brazil. Methods: Blood samples of 186 non-syndromic orofacial clefts patients and 182 controls from Rio Grande do Norte, Brazil, were obtained to analyze IRF6 polymorphisms (rs2235371, rs642961, rs2236907, rs861019, and rs1044516) by real-time polymerase chain reaction. Non-syndromic orofacial clefts patients were classified in cleft lip and palate, cleft palate only and cleft lip only groups. Results: The genotype and allele frequencies of single nucleotide polymorphism rs2235371 in IRF6 showed significant differences in patients with cleft palate when compared to the controls, whereas no association was shown between rs642961, rs2236907, rs861019, and rs1044516 and non-syndromic orofacial clefts. Conclusion: The association found between rs2235371 and isolated cleft palate should be interpreted with caution due to the low number of individuals investigated, and more studies with larger sample size are needed to confirm these association. In addition, there is a lack of association of the rs642961, rs2236907 and rs861019 polymorphisms with non-syndromic orofacial clefts susceptibility.

Resumo Introdução: As fendas orofaciais não sindrômicas possuem uma etiologia complexa devido à contribuição de fatores de risco genéticos e ambientais, assim como a interação entre eles. Dentre os mais de 15loci de susceptibilidade para as fendas orofaciais não sindrômicas com considerável suporte estatístico e biológico, o IRF6 é o gene mais validado pela maioria dos estudos. Apesar disso, em populações geneticamente heterogêneas como a brasileira, a confirmação da associação entre as fendas orofaciais não sindrômicas e as variantes mais comuns do IRF6 ainda não é um fato consolidado e outras variantes não tão conhecidas IRF6 são pouco investigadas. Objetivo: O objetivo deste estudo foi investigar a associação de variados polimorfismos do IRF6 com o desenvolvimento das fendas orofaciais não sindrômicas em uma população do nordeste do Brasil. Método: Amostras de sangue de 186 pacientes com fendas orofaciais não sindrômicas e 182 controles do estado do Rio Grande do Norte, Brasil, foram obtidas para analisar os polimorfismos do IRF6 (rs2235371, rs642961, rs2236907, rs861019 e rs1044516) por reação em cadeia da polimerase em tempo real. Os pacientes com fendas orofaciais não sindrômicas foram classificados em fenda labiopalatina, fenda palatina isolada e fenda labial isolada. Resultados: As frequências genotípica e alélica do polimorfismo de único nucleotídeo rs2235371 no IRF6 mostraram-se significativamente diferentes em pacientes com fenda palatina isolada quando comparadas às dos controles, enquanto que nenhuma associação foi encontrada entre rs642961, rs2236907, rs861019 e rs1044516 e risco para o desenvolvimento das fendas orofaciais não sindrômicas. Conclusão: A associação encontrada entre rs2235371 e fenda palatina isolada deve ser interpretada com cautela devido ao baixo número de indivíduos investigados, sendo necessários mais estudos com um tamanho amostral maior para confirmar essa associação. Além disso, não foram encontradas associações significativas entre os demais polimorfismos do IRF6 rs642961, rs2236907, rs861019 e rs1044516 e a susceptibilidade às fendas orofaciais não sindrômicas.

IRF6 rs2235375 single nucleotide polymorphism is associated with isolated non-syndromic cleft palate but not with cleft lip with or without palate in South Indian population / Polimorfismo de nucleotídeo único do gene IRF6 rs2235375 está associado com à fenda palatina isolada não sindrômica, mas não com fenda labial com ou sem fenda palatina em população do sul da Índia

Abstract Introduction Transcription factors are very diverse family of proteins involved in activating or repressing the transcription of a gene at a given time. Several studies using animal models demonstrated the role of transcription factor genes in craniofacial development. Objective We aimed to investigate the association of IRF6 intron-6 polymorphism in the non-syndromic cleft lip with or without palate in a South Indian population. Methods 173 unrelated nonsyndromic cleft lip with or without cleft palate patients and 176 controls without clefts patients were genotyped for IRF6 rs2235375 variant by allele-specific amplification using the KASPar single nucleotide polymorphism genotyping system. The association between interferon regulatory factor-6 gene intron-6 dbSNP208032210:g.G>C (rs2235375) single nucleotide polymorphism and non-syndromic cleft lip with or without palate risk was investigated by chi-square test. Results There were significant differences in genotype or allele frequencies of rs2235375 single nucleotide polymorphism between controls and cases with non-syndromic cleft lip with or without palate. IRF6 rs2235375 variant was significantly associated with increased risk of non-syndromic cleft lip with or without palate in co-dominant, dominant (OR: 1.19; 95% CI 1.03-2.51; p = 0.034) and allelic models (OR: 1.40; 95% CI 1.04-1.90; p = 0.028). When subset analysis was applied significantly increased risk was observed in cleft palate only group (OR dominant: 4.33; 95% CI 1.44-12.97; p = 0.005). Conclusion These results suggest that IRF6 rs2235375 SNP play a major role in the pathogenesis and risk of developing non-syndromic cleft lip with or without palate.

Resumo Introdução Fatores de transcrição constituem uma família de proteínas muito diversa envolvida na ativação ou repressão da transcrição de um gene, em um determinado momento. Vários estudos usando modelos animais demonstraram o papel dos genes do fator de transcrição no desenvolvimento craniofacial. Objetivo Nosso objetivo foi investigar a associação do polimorfismo IRF6 intron-6 na fenda labial não sindrômica com ou sem fenda palatina em uma população do sul da Índia. Método Um total de 173 pacientes com fenda labial não sindrômica com ou sem fenda palatina e 176 controles sem fendas foram genotipados para a variante IRF6 rs2235375 por amplificação alelo-específica utilizando o sistema KASPar de genotipagem de polimorfismo de nucleotídeo único. A associação entre o polimorfismo de nucleotídeo único Fator 6 Regulatório do Interferon (IRF6) intron-6 dbSNP208032210:g.G>C (rs2235375) e o risco de fenda labial não sindrômica com ou sem fenda palatina foi investigado pelo teste qui-quadrado. Resultados Houve diferenças significativas nas frequências de genótipos ou alelos do rs2235375 SNP entre controles e casos com fenda labial não sindrômica com ou sem fenda palatina. A variante IRF6 rs2235375 foi significativamente associada ao aumento do risco de fenda labial não sindrômica com ou sem fenda palatina em modelos codominantes, dominantes (OR: 1,19; IC 95%: 1,03-2,51; p = 0,034) e alélicos (OR: 1,40; IC 95%: 1,04-1,90; p = 0,028). Quando a análise do subgrupo foi realizada, um risco significativamente aumentado foi observado no grupo Fenda Palatina Isolada (OR dominante: 4,33; IC 95%: 1,44-12,97; p = 0,005). Conclusões Esses resultados sugerem que o polimorfismo de nucleotídeo único IRF6 rs2235375 desempenha um papel importante na patogênese e no risco de desenvolvimento de fenda labial não sindrômica com ou sem fenda palatina.

Association of single nucleotide polymorphisms in AXIN2, BMP4, and IRF6 with Non-Syndromic Cleft Lip with or without Cleft Palate in a sample of the southeast Iranian population

Abstract Non-syndromic cleft lip with or without palate (NSCL/P) is a common congenital malformation worldwide, with complex etiology. It has been proposed that interaction of genes and environmental factors play a role in the predisposition to this disease. Objectives: The aim of this study was to examine the association between AXIN2 (axis inhibition protein 2) rs7224837, BMP4 (bone morphogenetic protein 4) rs17563, and IRF6 (interferon regulatory factor 6) rs861019 and 2235371 polymorphisms and NSCL/P in an Iranian population. Material and Methods: This case-control study was carried out on 132 unrelated NSCL/P patients and 156 healthy subjects. The variants were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: The findings suggest that BMP4 rs17563 polymorphism significantly decreased the risk of NSCL/P in codominant (OR=0.36, 95%CI=0.17-0.79, p=0.012, CT vs CC and OR=0.11, 95%CI=0.01-0.88, p = 0.019, TT vs CC), dominant (OR=0.30, 95%CI=0.15-0.62, p = 0.0007, CT+TT vs CC), recessive (OR=0.12, 95%CI=0.02-0.99, p = 0.023, TT vs CC+CT), overdominant (OR=0.39, 95%CI = 0.18-0.84, p=0.021, CT vs CC+TT), and allele (OR=0.28, 95%CI=0.15-0.55, p<0.0001, T vs C) inheritance models. Our findings did not support an association between AXIN2 rs7224837 and IRF6 rs861019 polymorphism and risk/protection of NSCL/P. The IRF6 2235371 variant was not polymorphic in our population. Conclusion: The results indicate that the BMP4 rs17563 variant is likely to confer a protective effect against the occurrence of NSCL/P in a sample of the southeast Iranian population.

Identification of Novel Methylation Markers in Hepatocellular Carcinoma using a Methylation Array

Promoter CpG island hypermethylation has become recognized as an important mechanism for inactivating tumor suppressor genes or tumor-related genes in human cancers of various tissues. Gene inactivation in association with promoter CpG island hypermethylation has been reported to be four times more frequent than genetic changes in human colorectal cancers. Hepatocellular carcinoma is also one of the human cancer types in which aberrant promoter CpG island hypermethylation is frequently found. However, the number of genes identified to date as hypermethylated for hepatocellular carcinoma (HCC) is fewer than that for colorectal cancer or gastric cancer, which can be attributed to fewer attempts to perform genome-wide methylation profiling for HCC. In the present study, we used bead-array technology and coupled methylation-specific PCR to identify new genes showing cancer-specific methylation in HCC. Twenty-four new genes have been identified as hypermethylated at their promoter CpG island loci in a cancer-specific manner. Of these, TNFRSF10C, HOXA9, NPY, and IRF5 were frequently hypermethylated in hepatocellular carcinoma tissue samples and their methylation was found to be closely associated with inactivation of gene expression. Further study will be required to elucidate the clinicopathological implications of these newly found DNA methylation markers in hepatocellular carcinoma.

Triagem de mutação no éxon 3 do gene IRF6 em indivíduos com fissura labiopalatina e agenesia dentária: padronização de protocolo para seqüenciamento de DNA genômico a partir de saliva / Screening of mutation in IRF6 gene of subjects with cleft lip and palate and tooth agenesis: protocol standardization for sequencing of genomic DNA extracted from saliva

A fissura labiopalatina e a agenesia dentária são consideradas alterações do desenvolvimento embrionário. Esses fenótipos ocorrem em decorrência da interação de fatores genéticos e ambientais, caracterizando um padrão de herança multifatorial. Entre os genes candidatos a esses fenótipos destaca-se o IRF6. Para esses estudos genéticos podem ser usadas diferentes metodologias, dentre elas o seqüenciamento direto. A proposta deste estudo foi primeiramente padronizar um protocolo para seqüenciamento direto de DNA genômico a partir de saliva e então investigar mutações ou polimorfismos no éxon 3 do gene IRF6 em indivíduos com fissura de lábio e palato unilateral não-sindrômica e agenesia dentária. Fizeram parte do estudo 120 voluntários distribuídos em quatro grupos: Grupo 1 30 indivíduos com fissura e agenesia dentária; Grupo 2 - 30 indivíduos somente com fissura; Grupo 3 - 30 indivíduos somente com agenesia dentária e Grupo 4 - Controle. Para análise do éxon 3 do gene IRF6 foi coletada saliva, e a partir desse material foram testados três protocolos para extração de DNA genômico. Além disso, durante a padronização do protocolo para seqüenciamento direto foram avaliadas metodologias diferentes para outras três etapas da preparação das amostras: purificação do produto de PCR, otimização na utilização do BigDye® v3.1 Terminator na reação de seqüenciamento e purificação do produto da reação de seqüenciamento. As amostras foram seqüenciadas em Analisador Genético ABI 3130XL e os resultados analisados por meio de programas de computador específicos. Foram pesquisadas, nos eletroferogramas referentes ao éxon 3 do gene IRF6, variações nas seqüências de cada indivíduo. Os resultados mostraram que o protocolo de extração de DNA a partir de saliva utilizando InstaGeneTM Matrix associado à proteinase K e dodecil sulfato de sódio 1% foi o que apresentou melhores resultados na quantidade e qualidade do DNA extraído. Em relação à purificação do produto de PCR, o método de...

Cleft lip and palate and tooth agenesis are considered changes in embryonic development. These phenotypes occur as a result of the interaction of genetic and environmental factors, suggesting a multifactorial inheritance pattern. Among the candidate genes for these phenotypes IRF6 appears as one of the most important. Direct sequencing, among other techniques, can be used to perform such genetic studies. The aim of this study was to standardize a protocol for direct sequencing of genomic DNA extracted from whole saliva to allow further search of mutations or polymorphisms in exon 3 of IRF6 gene in individuals with nonsyndromic cleft lip and palate and tooth agenesis. Volunteers were 120 subjects divided into four groups: Group 1 - 30 individuals with tooth agenesis and cleft, Group 2 - 30 individuals with cleft only, Group 3 - 30 individuals with tooth agenesis only, and Group 4 - Control. For the analysis of the exon 3 of IRF6 gene, saliva was collected to test three protocols for the extraction of genomic DNA. Additionally, during the protocol standardization for direct sequencing, different methodologies for the other three steps of sample preparation were evaluated: purification of PCR product, optimization of the use of BigDye® v3.1 Terminator, and purification of the sequencing product. The samples were sequenced on ABI 3130XL Genetic Analyzer, and the results were analyzed using specific softwares. Heterozygous and homozygous variations in the sequences of the exon 3 of IRF6 gene of each individual were searched in the electropherograms. The results showed that the protocol for DNA extraction from saliva using InstageneTM Matrix associated with proteinase K and 1% sodium dodecyl sulfate showed the best results in the quantity and quality of the extracted DNA. As far as the purification of the PCR product, the method of choice was the purification in specific columns. BigDye® v3.1 was used with success in a volume 2 L per reaction, and the purification...

Development of Monoclonal Antibodies Against Human IRF-5 and Their Use in Identifying the Binding of IRF-5 to Nuclear Import Proteins Karyopherin-alpha1 and -beta1

PURPOSE: IRF-5 is a direct transducer of virus-mediated and TLR-mediated signaling pathways for the expression of cytokines and chemokines which form homodimers or heterodimers with IRF-7. However, direct IRF-5-specific monoclonal antibodies (mAbs) are not available at present. These could be used to further evaluate the functions of IRF-5. In this study, we produced and characterized three mouse mAbs to human IRF-5. The binding of IRF-5 to nuclear import proteins was first identified using a mAb. MATERIALS AND METHODS: His-tagged human IRF-5 protein spanning amino acid residues 193- 257 was used as an antigen and three mAbs were produced. The mAbs were tested with ELISA, Western blot analysis (WB), immunofluorescent staining (IF), and immunoprecipitation (IP). In addition, the nuclear import protein which carried phosphorylated IRF-5 was identified using one of these mAbs. RESULTS: MAbs 5IRF8, 5IRF10 and 5IRF24 which reacted with the recombinant His-IRF-5(193-257) protein were produced. All mAbs bound to human IRF-5, but not to IRF-3 or IRF-7. They could be used for WB, IF, and IP studies. The binding of phosphorylated IRF-5 to karyopherin-alpha1 and -beta1 was also identified. CONCLUSION: Human IRF-5-specific mAbs are produced for studying the immunologic roles related to IRF-5. Phosphorylated IRF-5 is transported to the nucleus by binding to nuclear import proteins karyopherin-alpha1 and -beta1.