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Cassim A, Hettiarachchi D, Dissanayake VHW. Genetic determinants of syndactyly: perspectives on pathogenesis and diagnosis. Orphanet J Rare Dis 2022; 17:198. [PMID: 35549993 PMCID: PMC9097448 DOI: 10.1186/s13023-022-02339-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 04/26/2022] [Indexed: 12/04/2022] Open
Abstract
The formation of the digits is a tightly regulated process. During embryogenesis, disturbance of genetic pathways in limb development could result in syndactyly; a common congenital malformation consisting of webbing in adjacent digits. Currently, there is a paucity of knowledge regarding the exact developmental mechanism leading to this condition. The best studied canonical interactions of Wingless‐type–Bone Morphogenic Protein–Fibroblast Growth Factor (WNT–BMP–FGF8), plays a role in the interdigital cell death (ICD) which is thought to be repressed in human syndactyly. Animal studies have displayed other pathways such as the Notch signaling, metalloprotease and non-canonical WNT-Planar cell polarity (PCP), to also contribute to failure of ICD, although less prominence has been given. The current diagnosis is based on a clinical evaluation followed by radiography when indicated, and surgical release of digits at 6 months of age is recommended. This review discusses the interactions repressing ICD in syndactyly, and characterizes genes associated with non-syndromic and selected syndromes involving syndactyly, according to the best studied canonical WNT-BMP-FGF interactions in humans. Additionally, the controversies regarding the current syndactyly classification and the effect of non-coding elements are evaluated, which to our knowledge has not been previously highlighted. The aim of the review is to better understand the developmental process leading to this condition.
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Affiliation(s)
- Afraah Cassim
- Human Genetics Unit, Faculty of Medicine, University of Colombo, 25, Kynsey Road, Colombo, Sri Lanka.
| | - Dineshani Hettiarachchi
- Human Genetics Unit, Faculty of Medicine, University of Colombo, 25, Kynsey Road, Colombo, Sri Lanka
| | - Vajira H W Dissanayake
- Human Genetics Unit, Faculty of Medicine, University of Colombo, 25, Kynsey Road, Colombo, Sri Lanka
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Peng Q, Qin W, Li S, Huang M, Rao C, Lu X. A Novel IRF6 Frameshift Mutation in a Large Chinese Pedigree With Van der Woude syndrome. Cleft Palate Craniofac J 2021; 59:548-553. [PMID: 33906476 DOI: 10.1177/10556656211010909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
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.
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Affiliation(s)
- Qi Peng
- Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, Guangdong, China.,Medical Laboratory, Dongguan Children's Hospital, Dongguan, Guangdong, China.,Key Laboratory for Children's Genetics and Infectious Diseases of Dongguan, Dongguan, Guangdong, China
| | - Wenyan Qin
- CapitalBio Technology Corporation, Beijing, China
| | - Siping Li
- Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, Guangdong, China.,Medical Laboratory, Dongguan Children's Hospital, Dongguan, Guangdong, China.,Key Laboratory for Children's Genetics and Infectious Diseases of Dongguan, Dongguan, Guangdong, China
| | - Meihua Huang
- Department of Stomatology, Dongguan Eighth People's Hospital, Dongguan, Guangdong, China
| | - Chunbao Rao
- Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, Guangdong, China.,Medical Laboratory, Dongguan Children's Hospital, Dongguan, Guangdong, China.,Key Laboratory for Children's Genetics and Infectious Diseases of Dongguan, Dongguan, Guangdong, China
| | - Xiaomei Lu
- Department of Medical and Molecular Genetics, Dongguan Institute of Pediatrics, Dongguan, Guangdong, China.,Medical Laboratory, Dongguan Children's Hospital, Dongguan, Guangdong, China.,Key Laboratory for Children's Genetics and Infectious Diseases of Dongguan, Dongguan, Guangdong, China
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Yu Y, Wan Y, Qin C, Yue H, Bian Z, He M. Novel IRF6 mutations in Chinese Han families with Van der Woude syndrome. Mol Genet Genomic Med 2020; 8:e1196. [PMID: 32108996 PMCID: PMC7216816 DOI: 10.1002/mgg3.1196] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 02/02/2020] [Accepted: 02/14/2020] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Interferon Regulatory Factor 6 (IRF6) gene encodes a member of the IRF family of transcription factors. Mutations in IRF6 cause Van der Woude Syndrome (VWS), which is the most common malformation of syndromic orofacial clefts in humans. METHODS Here, we performed sequencing studies of six families with VWS in the Chinese Han population. The entire IRF6-coding region and the exon-intron boundaries including exons 3-8 and part of exon 9 were screened among all the collected family members by Sanger sequencing. RESULTS We found a novel splice site variant c.175-6T>A, two novel missense variants (p.Lys66Arg and p.Pro107Thr), in addition with a previously reported missense variant (p.Leu87Phe), which were all located in and nearby exon 4 of IRF6. Meanwhile, a novel frameshift variant p.G257Vfs*46 in exon 7 of IRF6 was also detected. All the mutations presented to be co-segregated in each family. CONCLUSION Our study has advanced the understanding of the genetic architecture of VWS and provides the basis for genetic counseling, antenatal diagnosis, and gene therapy of high risk groups.
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Affiliation(s)
- Yanqin Yu
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Yatao Wan
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, Wuhan University, Wuhan, China
| | - Chuanqi Qin
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Haitang Yue
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Zhuan Bian
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Miao He
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, China
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